View source for Medicine:Coronavirus disease 2019

{{short description|Infectious respiratory disease caused by severe acute respiratory syndrome coronavirus 2}}
{{Use Commonwealth English|date=March 2020}}
{{Infobox medical condition
| name = Coronavirus disease 2019<br>(COVID-19)
| synonyms =
* Coronavirus
* Corona
* COVID
* 2019-nCoV acute respiratory disease
* Sars-Cov
* Novel coronavirus pneumonia<ref name="chinamortality" /><ref>{{cite journal |vauthors=Han X, Cao Y, Jiang N, Chen Y, Alwalid O, Zhang X, Gu J, Dai M, Liu J, Zhu W, Zheng C, Shi H |display-authors=6 |title=Novel Coronavirus Pneumonia (COVID-19) Progression Course in 17 Discharged Patients: Comparison of Clinical and Thin-Section CT Features During Recovery |journal=Clinical Infectious Diseases |date=March 2020 |pmid=32227091 |pmc=7184369 |doi=10.1093/cid/ciaa271 |doi-access=free}}</ref>
* Severe pneumonia with novel pathogens<ref>{{cite web |title=Special Act for Prevention, Relief and Revitalization Measures for Severe Pneumonia with Novel Pathogens–Article Content–Laws & Regulations Database of The Republic of China |url=https://law.moj.gov.tw/ENG/LawClass/LawAll.aspx?pcode=L0050039 |website=law.moj.gov.tw |access-date=10 May 2020}}</ref>
| pronounce = {{ubl|{{IPAc-en|k|ə|ˈ|r|oʊ|n|ə|ˌ|v|aɪ|r|ə|s|_|d|ɪ|ˈ|z|i:|z}}|{{IPAc-en|ˌ|k|oʊ|v|ɪ|d|n|aɪ|n|ˈ|t|iː|n|,_|ˌ|k|ɒ|v|ɪ|d|-}}<ref>{{cite web |url=https://oed.com/view/Entry/88575495 |title=Covid-19, n. |website=Oxford English Dictionary |access-date=15 April 2020}}</ref>}}
| image = File:Novel Coronavirus SARS-CoV-2.jpg
| image_size = 250px
| caption = {{longitem|[[False color]] transmission electron microscope image of Coronavirus}}
| specialty = [[Medicine:Infectious disease (medical specialty)|Infectious disease]]
| symptoms = Fever, cough, fatigue, shortness of breath, loss of smell; sometimes no symptoms at all<ref name=CDC2020Sym/><ref name="WHO2020QA" />
| complications = [[Medicine:Viral pneumonia|Pneumonia]], viral sepsis, [[Medicine:Acute respiratory distress syndrome|acute respiratory distress syndrome]], [[Medicine:Acute kidney injury|kidney failure]], [[Medicine:Cytokine release syndrome|cytokine release syndrome]]
| onset = 2–14 days (typically 5) from infection
| duration =
| types =
| cause = [[Biology:Severe acute respiratory syndrome coronavirus 2|Severe acute respiratory syndrome coronavirus 2]] (SARS-CoV-2)
| risks = 
| diagnosis = [[Biology:Reverse transcription polymerase chain reaction|rRT-PCR testing]], [[CT scan]]
| differential =
| prevention = Hand washing, face coverings, [[Medicine:Quarantine|quarantine]], [[Medicine:Social distancing|social distancing]]<ref name=Quar2020>{{cite journal |vauthors=Nussbaumer-Streit B, Mayr V, Dobrescu AI, Chapman A, Persad E, Klerings I, Wagner G, Siebert U, Christof C, Zachariah C, Gartlehner G |display-authors=6 |title=Quarantine alone or in combination with other public health measures to control COVID-19: a rapid review |journal=The Cochrane Database of Systematic Reviews |volume=4 |pages=CD013574 |date=April 2020 |pmid=32267544 |pmc=7141753 |doi=10.1002/14651858.CD013574}}</ref>
| treatment = [[Medicine:Symptomatic treatment|Symptomatic and supportive]]
| medication =
| prognosis =
| frequency = {{Cases in the COVID-19 pandemic|confirmed|editlink=|ref=yes}} confirmed cases
| deaths = {{Cases in the COVID-19 pandemic|deaths|editlink=|ref=no}} ({{Cases in the COVID-19 pandemic|ratio|editlink=|ref=no}} of confirmed cases){{Cases in the COVID-19 pandemic|ref=yes}}
}}
<!-- 1) Definition and epidemiology -->
'''Coronavirus disease 2019''' ('''COVID-19''') is an [[Medicine:Infectious disease|infectious disease]] caused by [[Biology:Severe acute respiratory syndrome coronavirus 2|severe acute respiratory syndrome coronavirus 2]] (SARS-CoV-2).<ref>{{cite web |url=https://www.mayoclinic.org/diseases-conditions/coronavirus/symptoms-causes/syc-20479963 |title=Coronavirus disease 2019 (COVID-19)—Symptoms and causes |website=Mayo Clinic |access-date=14 April 2020}}</ref> It was first identified in December 2019 in [[Place:Wuhan|Wuhan]], Hubei, China, and has resulted in an ongoing pandemic.<ref name="Hui14Jan2020">{{cite journal |vauthors=Hui DS, I Azhar E, Madani TA, Ntoumi F, Kock R, Dar O, Ippolito G, Mchugh TD, Memish ZA, Drosten C, Zumla A, Petersen E |display-authors=6 |title=The continuing 2019-nCoV epidemic threat of novel coronaviruses to global health—The latest 2019 novel coronavirus outbreak in Wuhan, China |journal=International Journal of Infectious Diseases |volume=91 |issue= |pages= 264–266 |date=February 2020 |pmid=31953166 |pmc=7128332 |doi=10.1016/j.ijid.2020.01.009 |doi-access=free}}</ref><ref name="WHOPandemic">{{cite press release |title=WHO Director-General's opening remarks at the media briefing on COVID-19 |website=[[Organization:World Health Organization|World Health Organization]] (WHO) |date=11 March 2020 |url=https://www.who.int/dg/speeches/detail/who-director-general-s-opening-remarks-at-the-media-briefing-on-covid-19---11-march-2020 |access-date=12 March 2020 |url-status=live |archive-url=https://web.archive.org/web/20200311212521/https://www.who.int/dg/speeches/detail/who-director-general-s-opening-remarks-at-the-media-briefing-on-covid-19---11-march-2020 |archive-date=11 March 2020}}</ref> The first confirmed case has been traced back to 17 November 2019 in Hubei.<ref name="tracedback">{{Cite web|last=Ma|first=Josephine|date=13 March 2020|title=Coronavirus: China's first confirmed Covid-19 case traced back to November 17|url=https://www.scmp.com/news/china/society/article/3074991/coronavirus-chinas-first-confirmed-covid-19-case-traced-back|url-status=live|archive-url=https://web.archive.org/web/20200313004217/https://www.scmp.com/news/china/society/article/3074991/coronavirus-chinas-first-confirmed-covid-19-case-traced-back|archive-date=13 March 2020|access-date=28 May 2020|website=South China Morning Post}}</ref> As of {{Cases in the COVID-19 pandemic|date|editlink=|ref=no}}, more than {{Cases in the COVID-19 pandemic|conround|editlink=|ref=no}} cases have been reported across {{Cases in the COVID-19 pandemic|territories|ref=no}} countries and territories, resulting in more than {{Cases in the COVID-19 pandemic|dround|editlink=|ref=no}} deaths. More than {{Cases in the COVID-19 pandemic|recround|editlink=|ref=no}} people have recovered.{{Cases in the COVID-19 pandemic|ref=yes}}

<!-- 2) Symptoms -->
Common symptoms include fever, cough, fatigue, shortness of breath, and [[Medicine:Anosmia|loss of smell]] and taste.<ref name=autogenerated1>{{cite journal |last1=Grant |first1=Michael C. |last2=Geoghegan |first2=Luke |last3=Arbyn |first3=Marc |last4=Mohammed |first4=Zakaria |last5=McGuinness |first5=Luke |last6=Clarke |first6=Emily L. |last7=Wade |first7=Ryckie G. |last8=Hirst |first8=Jennifer A. |s2cid=220046286 |title=The prevalence of symptoms in 24,410 adults infected by the novel coronavirus (SARS-CoV-2; COVID-19): A systematic review and meta-analysis of 148 studies from 9 countries |journal=PLOS ONE |date=23 June 2020 |volume=15 |issue=6 |pages=e0234765 |doi=10.1371/journal.pone.0234765|pmid=32574165 |pmc=7310678 }}</ref><ref name="CDC2020Sym" /><ref name="WHO2020QA" /><ref name="entuk-anosmia" /> While the majority of cases result in mild symptoms, some progress to [[Medicine:Acute respiratory distress syndrome|acute respiratory distress syndrome]] (ARDS) possibly precipitated by [[Medicine:Cytokine storm|cytokine storm]],<ref>{{cite journal |vauthors=Ye Q, Wang B, Mao J |title=The pathogenesis and treatment of the 'Cytokine Storm' in COVID-19 |journal=J. Infect. |volume=80 |issue=6 |pages=607–613 |date=June 2020 |pmid=32283152 |pmc=7194613 |doi=10.1016/j.jinf.2020.03.037 |url=}}</ref> [[Medicine:Multiple organ dysfunction syndrome|multi-organ failure]], [[Medicine:Septic shock|septic shock]], and blood clots.<ref name="auto">{{cite journal |vauthors=Murthy S, Gomersall CD, Fowler RA |title=Care for Critically Ill Patients With COVID-19 |journal=JAMA |volume=323 |issue=15 |pages=1499 |date=March 2020 |pmid=32159735 |doi=10.1001/jama.2020.3633 |doi-access=free}}</ref><ref>{{cite book |title=StatPearls |vauthors=Cascella M, Rajnik M, Cuomo A, Dulebohn SC, Di Napoli R |date=2020 |publisher=StatPearls Publishing |location=Treasure Island (FL) |chapter=Features, Evaluation and Treatment Coronavirus (COVID-19) |pmid=32150360 |access-date=18 March 2020 |chapter-url=http://www.ncbi.nlm.nih.gov/books/NBK554776/}}</ref><ref>{{cite journal |vauthors=Bikdeli B, Madhavan MV, Jimenez D, Chuich T, Dreyfus I, Driggin E, Nigoghossian C, Ageno W, Madjid M, Guo Y, Tang LV, Hu Y, Giri J, Cushman M, Quéré I, Dimakakos EP, Gibson CM, Lippi G, Favaloro EJ, Fareed J, Caprini JA, Tafur AJ, Burton JR, Francese DP, Wang EY, Falanga A, McLintock C, Hunt BJ, Spyropoulos AC, Barnes GD, Eikelboom JW, Weinberg I, Schulman S, Carrier M, Piazza G, Beckman JA, Steg PG, Stone GW, Rosenkranz S, Goldhaber SZ, Parikh SA, Monreal M, Krumholz HM, Konstantinides SV, Weitz JI, Lip GY |display-authors=6 |title=COVID-19 and Thrombotic or Thromboembolic Disease: Implications for Prevention, Antithrombotic Therapy, and Follow-up |journal=Journal of the American College of Cardiology |date=April 2020 |volume=75 |issue=23 |pages=2950–2973 |pmid=32311448 |doi=10.1016/j.jacc.2020.04.031 |pmc=7164881}}</ref> The [[Medicine:Incubation period|time from exposure to onset of symptoms]] is typically around five days, but may range from two to fourteen days.<ref name="CDC2020Sym" /><ref>{{cite journal |vauthors=Velavan TP, Meyer CG |title=The COVID-19 epidemic |journal=Tropical Medicine & International Health |volume=25 |issue=3 |pages=278–280 |date=March 2020 |pmid=32052514 |pmc=7169770 |doi=10.1111/tmi.13383 |doi-access=free}}</ref>

<!-- 3) Spread and diagnosis --><!-- DO NOT INTERFERE WITH THE SECTION BEGIN/END TAGS, AS IT WILL BREAK THE PANDEMIC ARTICLE --><section begin="Spread"/>The virus is primarily [[Medicine:Transmission|spread]] between people during close contact,{{efn|Close contact is defined as less than one metre (~3.3 feet) by the WHO<ref name="WHO2020QA">{{cite web |url=https://www.who.int/emergencies/diseases/novel-coronavirus-2019/question-and-answers-hub/q-a-detail/q-a-coronaviruses |title=Q&A on coronaviruses (COVID-19) |date=17 April 2020 |publisher=[[Organization:World Health Organization|World Health Organization]] |archive-url=https://web.archive.org/web/20200514224315/https://www.who.int/emergencies/diseases/novel-coronavirus-2019/question-and-answers-hub/q-a-detail/q-a-coronaviruses |archive-date=14 May 2020 |url-status=live |access-date=14 May 2020}}</ref> and within ~1.8 metres (six feet) by the US Centers for Disease Control and Prevention (CDC).<ref name="CDCTrans">{{cite web |url=https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/how-covid-spreads.html |title=How COVID-19 Spreads |date=2 April 2020 |website=U.S. Centers for Disease Control and Prevention (CDC) |url-status=live |archive-url=https://web.archive.org/web/20200403001235/https://www.cdc.gov/coronavirus/2019-ncov/prepare/transmission.html |archive-date=3 April 2020 |access-date=3 April 2020}}</ref>|name=|group=}} most often via small droplets produced by coughing,{{efn|An uncovered cough can travel up to {{convert|8.2|m|ft|abbr=off}}.<ref name="Bourouiba, JAMA, 26 March">{{cite journal |vauthors=Bourouiba L |title=Turbulent Gas Clouds and Respiratory Pathogen Emissions: Potential Implications for Reducing Transmission of COVID-19 |journal=JAMA |date=March 2020 |pmid=32215590 |doi=10.1001/jama.2020.4756 |doi-access=free}}</ref>}} sneezing, and talking.<ref name="WHO2020QA"/><ref name=CDCTrans/><ref name="ECDCQA">{{cite web |url=https://www.ecdc.europa.eu/en/covid-19/questions-answers |title=Q & A on COVID-19 |website=European Centre for Disease Prevention and Control |access-date=30 April 2020}}</ref> The droplets usually fall to the ground or onto surfaces rather than travelling through air over long distances.<ref name="WHO2020QA"/><!-- These droplets are relatively heavy, do not travel far and quickly sink to the ground. --><ref>{{cite journal | vauthors = Stadnytskyi V, Bax CE, Bax A, Anfinrud P | title = The airborne lifetime of small speech droplets and their potential importance in SARS-CoV-2 transmission | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 117 | issue = 22 | pages = 11875–11877 | date = June 2020 | pmid = 32404416 | pmc = 7275719 | doi = 10.1073/pnas.2006874117 }}</ref> Transmission may also occur through [[Chemistry:Aerosol|smaller droplets]] that are able to stay suspended in the air for longer periods of time.<!-- Some medical procedures can produce very small droplets (called aerosolized droplet nuclei or aerosols) that are able to stay suspended in the air for longer periods of time. [...] aerosol transmission, particularly in these indoor locations where there are crowded and inadequately ventilated spaces where infected persons spend long periods of time with others, cannot be ruled out. --><ref name=":9">{{Cite web|title=Q&A: How is COVID-19 transmitted?|url=https://www.who.int/news-room/q-a-detail/q-a-how-is-covid-19-transmitted|access-date=2020-07-12|website=www.who.int|language=en}}</ref> Less commonly, people may become infected by touching a contaminated surface and then touching their face.<ref name="WHO2020QA" /><!-- These droplets land on objects and surfaces around the person. Other people then catch COVID-19 by touching these objects or surfaces, then touching their eyes, nose or mouth. --><ref name="CDCTrans" /><!-- The virus is thought to spread mainly from person-to-person [...] Between people who are in close contact with one another --> It is most contagious during the first three days after the onset of symptoms, although spread is possible before symptoms appear, and from people who do not show symptoms.<ref name="WHO2020QA" /><ref name="CDCTrans" /><!-- DO NOT REMOVE THE FOLLOWING TAG --><section end="Spread" /> The standard method of [[Medicine:Diagnosis|diagnosis]] is by real-time reverse transcription polymerase chain reaction (rRT-PCR) from a [[Nasopharyngeal swab|nasopharyngeal swab]].<ref name="CDC2020Testing">{{cite web |title=Interim Guidelines for Collecting, Handling, and Testing Clinical Specimens from Persons for Coronavirus Disease 2019 (COVID-19)|url=https://www.cdc.gov/coronavirus/2019-ncov/lab/guidelines-clinical-specimens.html |website=U.S. Centers for Disease Control and Prevention (CDC) |access-date=26 March 2020 |date=11 February 2020 |archive-url=https://web.archive.org/web/20200304165907/https://www.cdc.gov/coronavirus/2019-nCoV/lab/guidelines-clinical-specimens.html |archive-date=4 March 2020 |url-status=live }}</ref> Chest CT imaging may also be helpful for diagnosis in individuals where there is a high suspicion of infection based on symptoms and risk factors; however, guidelines do not recommend using CT imaging for routine screening.<ref name=":0">{{cite journal | vauthors = Salehi S, Abedi A, Balakrishnan S, Gholamrezanezhad A | title = Coronavirus Disease 2019 (COVID-19): A Systematic Review of Imaging Findings in 919 Patients | journal = AJR. American Journal of Roentgenology | pages = 87–93 | date = March 2020 | volume = 215 | issue = 1 | pmid = 32174129 | doi = 10.2214/AJR.20.23034 | doi-access = free }}</ref><ref name="acr.org">{{cite web|url=https://www.acr.org/Advocacy-and-Economics/ACR-Position-Statements/Recommendations-for-Chest-Radiography-and-CT-for-Suspected-COVID19-Infection|title=ACR Recommendations for the use of Chest Radiography and Computed Tomography (CT) for Suspected COVID-19 Infection | date=22 March 2020|website=American College of Radiology|url-status=live|archive-url=https://web.archive.org/web/20200328055813/https://www.acr.org/Advocacy-and-Economics/ACR-Position-Statements/Recommendations-for-Chest-Radiography-and-CT-for-Suspected-COVID19-Infection|archive-date=28 March 2020|access-date=}}</ref>

<!-- 4) Prevention -->
Recommended measures to prevent infection include frequent hand washing, [[Medicine:Social distancing|maintaining physical distance from others]] (especially from those with symptoms), [[Medicine:Quarantine|quarantine]] (especially for those with symptoms), covering coughs, and keeping unwashed hands away from the face.<ref name=Quar2020/><ref name="Advice for public">{{cite web|url=https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public|title=Advice for public|website=[[Organization:World Health Organization|World Health Organization]] (WHO)|access-date=25 February 2020|archive-url=https://web.archive.org/web/20200126025750/https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public|archive-date=26 January 2020|url-status=live| name-list-format = vanc}}</ref><ref>{{cite web|url=https://www.gov.uk/government/publications/covid-19-guidance-on-social-distancing-and-for-vulnerable-people/guidance-on-social-distancing-for-everyone-in-the-uk-and-protecting-older-people-and-vulnerable-adults|title=Guidance on social distancing for everyone in the UK|website=GOV.UK|access-date=25 March 2020|archive-url=https://web.archive.org/web/20200324214400/https://www.gov.uk/government/publications/covid-19-guidance-on-social-distancing-and-for-vulnerable-people/guidance-on-social-distancing-for-everyone-in-the-uk-and-protecting-older-people-and-vulnerable-adults|archive-date=24 March 2020|url-status=live}}</ref> The use of cloth face coverings such as a scarf or a bandana has been recommended by health officials in public settings to minimise the risk of transmissions, with some authorities requiring their use.<ref name=":2">{{Cite web|title=Recommendations for Cloth Face Covers|url=https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover.html|last=|date=3 April 2020|website=U.S. Centers for Disease Control and Prevention (CDC) |url-status=live|archive-url=|archive-date=|access-date=3 June 2020}}</ref><!-- Quote: "In light of this new evidence, CDC recommends wearing cloth face coverings in public settings where other social distancing measures are difficult to maintain" --><ref>{{cite journal|vauthors=Feng S, Shen C, Xia N, Song W, Fan M, Cowling BJ|date=May 2020|title=Rational use of face masks in the COVID-19 pandemic|journal=The Lancet. Respiratory Medicine|volume=8|issue=5|pages=434–436|doi=10.1016/S2213-2600(20)30134-X|pmc=7118603|pmid=32203710|doi-access=free}}</ref> Health officials also stated that medical-grade face masks, such as N95 masks, should only be used by healthcare workers, first responders, and those who directly care for infected individuals.<ref name="CDC2020IfSick">{{cite web|url=https://www.cdc.gov/coronavirus/2019-ncov/if-you-are-sick/steps-when-sick.html |title=What to Do if You Are Sick |vauthors=((Centers for Disease Control and Prevention)) |date=5 April 2020|website=U.S. Centers for Disease Control and Prevention (CDC)|url-status=live|archive-url=https://web.archive.org/web/20200214153016/https://www.cdc.gov/coronavirus/2019-ncov/about/steps-when-sick.html|archive-date=14 February 2020|access-date=24 April 2020 }}</ref><!-- Quote: "Note: During the COVID-19 pandemic, medical grade facemasks are reserved for healthcare workers and some first responders. You may need to make a cloth face covering using a scarf or bandana." --><ref name=WHO2020masks>{{cite web |title=When and how to use masks |url=https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public/when-and-how-to-use-masks |website=[[Organization:World Health Organization|World Health Organization]] (WHO) |access-date=24 April 2020 |archive-url=https://web.archive.org/web/20200307013848/https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public/when-and-how-to-use-masks |archive-date=7 March 2020 |url-status=live }}</ref><!-- Quote: "If you are healthy, you only need to wear a mask if you are taking care of a person with suspected 2019-nCoV infection." -->

<!-- 5) Management and history -->
There are no [[Medicine:COVID-19 vaccine|vaccines]] nor [[Biology:COVID-19 drug development|specific]] antiviral treatments for COVID-19.<ref name="WHO2020QA"/> Management involves the treatment of symptoms, supportive care, [[Medicine:Isolation (health care)|isolation]], and experimental measures.<ref name="cdc21Jan20202">{{cite web|url=https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/prevention.html |title=How to Protect Yourself & Others |date=8 April 2020|publisher=U.S. Centers for Disease Control and Prevention (CDC)|url-status=live|archive-url=https://web.archive.org/web/20200226145347/https://www.cdc.gov/coronavirus/2019-ncov/about/prevention-treatment.html|archive-date=26 February 2020|access-date=9 April 2020 }}</ref> The [[Organization:World Health Organization|World Health Organization]] (WHO) declared the COVID‑19 [[Medicine:Outbreak|outbreak]] a [[Social:Public health emergency of international concern|public health emergency of international concern]] (PHEIC)<ref>{{cite web|url=https://www.who.int/news-room/detail/30-01-2020-statement-on-the-second-meeting-of-the-international-health-regulations-(2005)-emergency-committee-regarding-the-outbreak-of-novel-coronavirus-(2019-ncov)|title=Statement on the second meeting of the International Health Regulations (2005) Emergency Committee regarding the outbreak of novel coronavirus (2019-nCoV)|website=[[Organization:World Health Organization|World Health Organization]] (WHO)|access-date=11 February 2020|archive-url=https://web.archive.org/web/20200131005904/https://www.who.int/news-room/detail/30-01-2020-statement-on-the-second-meeting-of-the-international-health-regulations-(2005)-emergency-committee-regarding-the-outbreak-of-novel-coronavirus-(2019-ncov)|archive-date=31 January 2020|url-status=live| name-list-format = vanc}}</ref><ref>{{cite news | vauthors = Mahtani S, Berger M, O'Grady S, Iati M | url = https://www.washingtonpost.com/world/asia_pacific/coronavirus-china-live-updates/2020/02/05/114ced8a-479c-11ea-bc78-8a18f7afcee7_story.html |title = Hundreds of evacuees to be held on bases in California; Hong Kong and Taiwan restrict travel from mainland China | work = {{wipe|The Washington Post}} | date = 6 February 2020 | access-date = 11 February 2020 | archive-url = https://web.archive.org/web/20200207134650/https://www.washingtonpost.com/world/asia_pacific/coronavirus-china-live-updates/2020/02/05/114ced8a-479c-11ea-bc78-8a18f7afcee7_story.html | archive-date = 7 February 2020 | url-status = live | name-list-format = vanc}}</ref> on 30 January 2020 and a [[Finance:Pandemic|pandemic]] on 11 March 2020.<ref name="WHOPandemic" /> Local transmission of the disease has occurred in most countries across all six WHO regions.<ref>{{cite web|url=https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200416-sitrep-87-covid-19.pdf?sfvrsn=9523115a_2|title=WHO Situation Report #87 | date=16 April 2020|website=[[Organization:World Health Organization|World Health Organization]] (WHO) |url-status=live|archive-url=|archive-date=|access-date=}}</ref>
thumb|thumbtime=0:02|upright=1.4|Video summary ([[Wikipedia:VideoWiki/Coronavirus disease 2019|script)]]

==Signs and symptoms==
{| class="wikitable" style = "float:right; margin-left:1em; text-align:center"
|+ Symptoms of COVID-19<ref name="CDC Interim Guidance">{{cite web|url=https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-guidance-management-patients.html|title=Interim Clinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19) |date=6 April 2020|website=U.S. Centers for Disease Control and Prevention (CDC) |access-date=19 April 2020|archive-url=https://web.archive.org/web/20200302201644/https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-guidance-management-patients.html|archive-date=2 March 2020|url-status=live}}</ref>
|-
! scope="col" | Symptom
! scope="col" | Range
|-
|Fever
|83–99%
|-
|Cough
|59–82%
|-
|Loss of appetite
|40–84%
|-
|Fatigue
|44–70%
|-
|Shortness of breath
|31–40%
|-
|Coughing up sputum
|28–33%
|-
|Muscle aches and pains
|11–35%
|}
[[File:Symptoms_of_coronavirus_disease_2019_4.0.svg|thumb|Symptoms of COVID-19.]]

[[Medicine:Fever|Fever]] is the most common symptom of COVID-19,<ref name=autogenerated1 /> but is highly variable in severity and presentation, with some older, immunocompromised, or critically ill people not having fever at all.<ref>{{cite journal | vauthors = Chavez S, Long B, Koyfman A, Liang SY | title = Coronavirus Disease (COVID-19): A primer for emergency physicians | journal = The American Journal of Emergency Medicine | date = March 2020 | pmid = 32265065 | pmc = 7102516 | doi = 10.1016/j.ajem.2020.03.036 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Tu H, Tu S, Gao S, Shao A, Sheng J | title = Current epidemiological and clinical features of COVID-19; a global perspective from China | journal = The Journal of Infection | date = April 2020 | volume = 81 | issue = 1 | pages = 1–9 | pmid = 32315723 | pmc = 7166041 | doi = 10.1016/j.jinf.2020.04.011 | doi-access = free }}</ref> In one study, only 44% of people had fever when they presented to the hospital, while 89% went on to develop fever at some point during their hospitalization.<ref>{{cite journal | last1=Guan | first1=Wei-jie | last2=Ni | first2=Zheng-yi | last3=Hu | first3=Yu | last4=Liang | first4=Wen-hua | last5=Ou | first5=Chun-quan | last6=He | first6=Jian-xing | last7=Liu | first7=Lei | last8=Shan | first8=Hong | last9=Lei | first9=Chun-liang | last10=Hui | first10=David S.C. | last11=Du | first11=Bin | last12=Li | first12=Lan-juan | last13=Zeng | first13=Guang | last14=Yuen | first14=Kwok-Yung | last15=Chen | first15=Ru-chong | last16=Tang | first16=Chun-li | last17=Wang | first17=Tao | last18=Chen | first18=Ping-yan | last19=Xiang | first19=Jie | last20=Li | first20=Shi-yue | last21=Wang | first21=Jin-lin | last22=Liang | first22=Zi-jing | last23=Peng | first23=Yi-xiang | last24=Wei | first24=Li | last25=Liu | first25=Yong | last26=Hu | first26=Ya-hua | last27=Peng | first27=Peng | last28=Wang | first28=Jian-ming | last29=Liu | first29=Ji-yang | last30=Chen | first30=Zhong | last31=Li | first31=Gang | last32=Zheng | first32=Zhi-jian | last33=Qiu | first33=Shao-qin | last34=Luo | first34=Jie | last35=Ye | first35=Chang-jiang | last36=Zhu | first36=Shao-yong | last37=Zhong | first37=Nan-shan | title=Clinical Characteristics of Coronavirus Disease 2019 in China | journal=New England Journal of Medicine | publisher=Massachusetts Medical Society | volume=382 | issue=18 | date=30 April 2020 | issn=0028-4793 | doi=10.1056/nejmoa2002032 | pages=1708–1720| pmid=32109013 | pmc=7092819 }}</ref>

Other common symptoms include cough, loss of appetite, fatigue, shortness of breath, sputum production, and [[Medicine:Myalgia|muscle]] and [[Medicine:Arthralgia|joint pains]].<ref name=autogenerated1 /><ref name="chinamortality" /><ref name="CDC2020Sym"><!-- KEEP THIS NAMED REFERENCE -->{{cite web|url=https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/symptoms.html |title=Symptoms of Coronavirus |date=13 May 2020|website=U.S. Centers for Disease Control and Prevention (CDC) |url-status=live|archive-url=https://web.archive.org/web/20200617081119/https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/symptoms.html|archive-date=17 June 2020|access-date=18 June 2020}}</ref><ref name="Hessen27Jan2020">{{cite web |url=https://www.elsevier.com/connect/coronavirus-information-center |title=Novel Coronavirus Information Center: Expert guidance and commentary |last=Hessen |first=Margaret Trexler | name-list-format = vanc |date=27 January 2020 |website=Elsevier Connect |url-status=live |access-date=31 January 2020 |archive-url=https://web.archive.org/web/20200130171622/https://www.elsevier.com/connect/coronavirus-information-center |archive-date=30 January 2020 }}</ref> Symptoms such as nausea, vomiting, and diarrhoea have been observed in varying percentages.<ref name=":10">{{cite ssrn|title=Clinical Characteristics of SARS-CoV-2 Infected Pneumonia with Diarrhea| vauthors = Wei XS, Wang X, Niu YR, Ye LL, Peng WB, Wang ZH, Yang WB, Yang BH, Zhang JC, Ma WL, Wang XR | display-authors = 6 |date=February 2020|ssrn = 3546120 }}</ref><ref name="Huang24Jan2020">{{cite journal | vauthors = Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y, Zhang L, Fan G, Xu J, Gu X, Cheng Z, Yu T, Xia J, Wei Y, Wu W, Xie X, Yin W, Li H, Liu M, Xiao Y, Gao H, Guo L, Xie J, Wang G, Jiang R, Gao Z, Jin Q, Wang J, Cao B | display-authors = 6 | title = Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China | journal = Lancet | volume = 395 | issue = 10223 | pages = 497–506 | date = February 2020 | pmid = 31986264 | pmc = 7159299 | doi = 10.1016/S0140-6736(20)30183-5 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Lai CC, Shih TP, Ko WC, Tang HJ, Hsueh PR | title = Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus disease-2019 (COVID-19): The epidemic and the challenges | journal = International Journal of Antimicrobial Agents | volume = 55 | issue = 3 | pages = 105924 | date = March 2020 | pmid = 32081636 | pmc = 7127800 | doi = 10.1016/j.ijantimicag.2020.105924 }}</ref> Less common symptoms include sneezing, runny nose, sore throat, and skin lesions.<ref name="WHOReport24Feb2020">{{cite report|url=https://www.who.int/docs/default-source/coronaviruse/who-china-joint-mission-on-covid-19-final-report.pdf|title=Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19)|date=16–24 February 2020|publisher=[[Organization:World Health Organization|World Health Organization]] (WHO)|access-date=21 March 2020|archive-url=https://web.archive.org/web/20200229221222/https://www.who.int/docs/default-source/coronaviruse/who-china-joint-mission-on-covid-19-final-report.pdf|archive-date=29 February 2020|url-status=live}}</ref> Some cases in China initially presented with only [[Medicine:Chest pain|chest tightness]] and [[Medicine:Palpitations|palpitations]].<ref name="Zheng Ma Zhang Xie p.">{{cite journal | vauthors = Zheng YY, Ma YT, Zhang JY, Xie X | title = COVID-19 and the cardiovascular system | journal = Nature Reviews. Cardiology | volume = 17 | issue = 5 | pages = 259–260 | date = May 2020 | pmid = 32139904 | pmc = 7095524 | doi = 10.1038/s41569-020-0360-5 | doi-access = free }}</ref> A decreased sense of smell or disturbances in taste may occur.<ref name="LancetIDSmell">{{cite journal |vauthors=Xydakis MS, Dehgani-Mobaraki P, Holbrook EH, Geisthoff UW, Bauer C, Hautefort C, Herman P, Manley GT, Lyon DM, Hopkins C |display-authors=6 |title=Smell and taste dysfunction in patients with COVID-19 |journal=The Lancet. Infectious Diseases |date=April 2020 |pmid=32304629 |pmc=7159875 |doi=10.1016/S1473-3099(20)30293-0 |url=https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30293-0/fulltext#%20}}</ref><ref>{{cite web |url=https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/symptoms.html |title=Symptoms of Coronavirus |date=27 April 2020 |website= |publisher=U.S. Centers for Disease Control and Prevention (CDC) |url-status=live |archive-url= |archive-date= |access-date=28 April 2020}}</ref><!-- Even though loss of smell as a symptom was first hyped and then fell back down to Earth, and even though other upper respiratory infections can cause loss of smell, I thought I'd keep some of technical terms which were here still available: anosmia means loss of smell, hyposmia means partial loss of smell, and dysgeusia means disturbance in taste. --> [[Medicine:Anosmia|Loss of smell]] was a presenting symptom in 30% of confirmed cases in South Korea.<ref name="entuk-anosmia">{{cite web |url=https://www.entuk.org/loss-sense-smell-marker-covid-19-infection |title=Loss of sense of smell as marker of COVID-19 infection |last=Hopkins |first=Claire |name-list-format=vanc |date= |website=Ear, Nose and Throat surgery body of United Kingdom |access-date=28 March 2020}}</ref><ref name="Iacobucci2020">{{cite journal |vauthors=Iacobucci G |title=Sixty seconds on ... anosmia |journal=BMJ |volume=368 |pages=m1202 |date=March 2020 |pmid=32209546 |doi=10.1136/bmj.m1202 |doi-access=free}}</ref>

As is common with infections, there is a delay between the moment a person is first infected and the time he or she develops symptoms. This is called the [[Medicine:Incubation period|incubation period]]. The typical incubation period for COVID‑19 is five or six days, but it can range from one to fourteen days<ref name="WHO2020QA" /><ref>{{cite report |vauthors=((World Health Organization)) |title=Coronavirus disease 2019 (COVID-19): situation report, 29 |date=19 February 2020 |publisher=World Health Organization |hdl=10665/331118 |hdl-access=free}}</ref> with approximately ten percent of cases taking longer.<ref>{{cite book |title=Rapid Expert Consultation Update on SARS-CoV-2 Surface Stability and Incubation for the COVID-19 Pandemic |website=TheNational Academies Press |date=27 March 2020 |doi=10.17226/25763 |isbn=978-0-309-67610-6 |url=https://www.nap.edu/read/25763/chapter/1 |access-date=18 May 2020}}</ref><ref>{{cite web |title=Interim Guidance: Public Health Management of cases and contacts associated with novel coronavirus (COVID-19) in the community |website=BC Centre for Disease Control |date=15 May 2020 |url=http://www.bccdc.ca/resource-gallery/Documents/Guidelines%20and%20Forms/Guidelines%20and%20Manuals/Epid/CD%20Manual/Chapter%201%20-%20CDC/2019-nCoV-Interim_Guidelines.pdf |access-date=18 May 2020}}</ref><ref>{{cite web |title=Rapid Review of the literature: Assessing the infection prevention and control measures for the prevention and management of COVID-19 in health and care settings |website=NHS Scotland |date=20 April 2020 |url=https://hpspubsrepo.blob.core.windows.net/hps-website/nss/2985/documents/1_covid-19-rapid-review-ipc-for-covid-19.pdf |access-date=18 May 2020}}</ref>

An early key to the diagnosis is the tempo of the illness. Early symptoms may include a wide variety of symptoms but infrequently involves shortness of breath. Shortness of breath usually develops several days after initial symptoms. Shortness of breath that begins immediately along with fever and cough is more likely to be anxiety than COVID-19. The most critical days of illness tend to be those following the development of shortness of breath.<ref>{{cite journal | vauthors = Cohen PA, Hall LE, John JN, Rapoport AB | title = The Early Natural History of SARS-CoV-2 Infection: Clinical Observations From an Urban, Ambulatory COVID-19 Clinic | journal = Mayo Clinic Proceedings | volume = 95 | issue = 6 | pages = 1124–1126 | date = June 2020 | pmid = 32451119 | doi = 10.1016/j.mayocp.2020.04.010 | pmc = 7167572 | doi-access = free }}</ref>
{{anchor|AsymptomaticAnchor}}
A minority of cases do not develop noticeable symptoms at any point in time.<ref name="Asymptomatic">{{cite journal | title=A systematic review of asymptomatic infections with COVID-19 | journal=Journal of Microbiology, Immunology and Infection | date=15 May 2020 | issn=1684-1182 | doi=10.1016/j.jmii.2020.05.001 | url=https://www.sciencedirect.com/science/article/pii/S1684118220301134 | access-date=13 June 2020 | page=| last1=Gao | first1=Zhiru | last2=Xu | first2=Yinghui | last3=Sun | first3=Chao | last4=Wang | first4=Xu | last5=Guo | first5=Ye | last6=Qiu | first6=Shi | last7=Ma | first7=Kewei | pmid=32425996 | pmc=7227597 }}</ref> These [[Medicine:Asymptomatic|asymptomatic]] carriers tend not to get tested, and their role in transmission is not fully known.<ref>{{cite web|url=https://www.cdc.gov/coronavirus/2019-ncov/hcp/faq.html|title=Clinical Questions about COVID-19: Questions and Answers |last=|date=11 February 2020|website=U.S. Centers for Disease Control and Prevention (CDC) |access-date=31 March 2020|archive-url=https://web.archive.org/web/20200214023335/https://www.cdc.gov/coronavirus/2019-ncov/hcp/faq.html|archive-date=14 February 2020|url-status=live}}</ref><ref>{{cite journal | vauthors = Lai CC, Liu YH, Wang CY, Wang YH, Hsueh SC, Yen MY, Ko WC, Hsueh PR | display-authors = 6 | title = Asymptomatic carrier state, acute respiratory disease, and pneumonia due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): Facts and myths | journal = Journal of Microbiology, Immunology, and Infection = Wei Mian Yu Gan Ran Za Zhi | date = March 2020 | volume = 53 | issue = 3 | pages = 404–412 | pmid = 32173241 | pmc = 7128959 | doi = 10.1016/j.jmii.2020.02.012 }}</ref> Preliminary evidence suggested they may contribute to the spread of the disease.<ref name="pmid32364890">{{cite journal | vauthors = Furukawa NW, Brooks JT, Sobel J | title = Evidence Supporting Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 While Presymptomatic or Asymptomatic | journal = Emerging Infectious Diseases | volume = 26 | issue = 7 | date = May 2020 | pmid = 32364890 | doi = 10.3201/eid2607.201595 | pmc = 7323549 | doi-access = free }}</ref> In June 2020, a spokeswoman of WHO said that asymptomatic transmission appears to be "rare," but the evidence for the claim was not released.<ref>{{Cite web|last1=Feuer|first1=William|last2=Higgins-Dunn|first2=Noah|date=8 June 2020|title=Asymptomatic spread of coronavirus is 'very rare,' WHO says|url=https://www.cnbc.com/2020/06/08/asymptomatic-coronavirus-patients-arent-spreading-new-infections-who-says.html|url-status=live|archive-url=|archive-date=|access-date=8 June 2020|website=CNBC}}</ref> The next day, WHO clarified that they had intended a narrow definition of "asymptomatic" that did not include pre-symptomatic or paucisymptomatic (weak symptoms) transmission and that up to 41% of transmission may be asymptomatic. Transmission without symptoms does occur.<ref name="Asymptomatic"/>

==Cause==
===Transmission===

<!-- DO NOT INTERFERE WITH THE SECTION BEGIN/END TAGS, AS IT WILL BREAK THE PANDEMIC ARTICLE -->
<section begin="Transmission"/>
alt=Cough/sneeze droplets visualised in dark background using Tyndall scattering|thumb|Respiratory droplets produced when a man [[sneezes, visualised using Tyndall scattering]]

COVID‑19 is a new disease, and many of the details of its [[Medicine:Transmission|spread]] are still under investigation.<ref name="WHO2020QA" /><ref name="CDCTrans" /><ref name="ECDCQA" /> It spreads easily between people—easier than [[Medicine:Influenza|influenza]] but not as easily as [[Medicine:Measles|measles]].<ref name="CDCTrans" /> People are most infectious when they show symptoms (even mild or non-specific symptoms), but may be infectious for up to two days before symptoms appear (pre-symptomatic transmission).<ref name="ECDCQA" /> They remain infectious an estimated seven to twelve days in moderate cases and an average of two weeks in severe cases.<ref name="ECDCQA" /> People can also transmit the virus without showing any symptom ([[Medicine:Asymptomatic|asymptomatic]] transmission), but it is unclear how often this happens.<ref name="WHO2020QA" /><ref name="CDCTrans" /><ref name="ECDCQA" /> A June 2020 review found that 40–45% of infected people are asymptomatic.<ref>{{cite journal|last1=Oran|first1=DP|last2=Topol|first2=EJ|date=3 June 2020|title=Prevalence of Asymptomatic SARS-CoV-2 Infection: A Narrative Review.|journal=Annals of Internal Medicine|doi=10.7326/M20-3012|pmc=7281624|pmid=32491919}}</ref> 

COVID-19 spreads primarily when people are in close contact and one person inhales small droplets produced by an infected person (symptomatic or not) coughing, sneezing, talking, or singing.<ref name="ECDCQA" /><ref>{{cite journal |vauthors=Hamner L, Dubbel P, Capron I, Ross A, Jordan A, Lee J, Lynn J, Ball A, Narwal S, Russell S, Patrick D, Leibrand H | s2cid=218647339 | display-authors=6 |title=High SARS-CoV-2 Attack Rate Following Exposure at a Choir Practice—Skagit County, Washington, March 2020 |journal=MMWR Morb. Mortal. Wkly. Rep. |volume=69 |issue=19 |pages=606–610 |date=May 2020 |pmid=32407303 |doi=10.15585/mmwr.mm6919e6 |url=https://www.cdc.gov/mmwr/volumes/69/wr/pdfs/mm6919e6-H.pdf }}</ref> The WHO recommends {{convert|1|m|ft|0}} of social distance;<ref name="WHO2020QA" /> the US Centers for Disease Control and Prevention (CDC) recommends {{convert|6|ft|m|0|order=flip}}.<ref name="CDCTrans" />

Transmission may also occur through [[Chemistry:Aerosol|aerosols]], smaller droplets that are able to stay suspended in the air for longer periods of time.<!--Some medical procedures can produce very small droplets (called aerosolized droplet nuclei or aerosols) that are able to stay suspended in the air for longer periods of time. [...] aerosol transmission, particularly in these indoor locations where there are crowded and inadequately ventilated spaces where infected persons spend long periods of time with others, cannot be ruled out.--><ref name=":9" />  Experimental results show the virus can survive in aerosol up to three hours.<ref>{{Cite journal |URL=https://oem.bmj.com/content/early/2020/06/30/oemed-2020-106707 |title=How should data on airborne transmission of SARS-CoV-2 change occupational health guidelines? |date=30 Jun 2020 |publisher=Occupational and Environmental Medicine |authors=Jean François Gehanno, Vincent Bonneterre, Pascal Andujar, Jean-Claude Pairon, Christophe Paris, Audrey Petit, Catherine Verdun-Esquer, Alexis Descatha, Quentin V Durand-Moreau, Patrick Brochard |archive-url=https://web.archive.org/web/20200705055235/https://oem.bmj.com/content/early/2020/06/30/oemed-2020-106707 |archive-date=5 Jul 2020}}</ref> Some outbreaks have also been reported in crowded and inadequately ventilated indoor locations where infected persons spend long periods of time (such as restaurants and nightclubs).<ref>{{Cite journal|last=Lewis|first=Dyani|date=2020-07-08|title=Mounting evidence suggests coronavirus is airborne — but health advice has not caught up|url=https://www.nature.com/articles/d41586-020-02058-1|journal=Nature|language=en|doi=10.1038/d41586-020-02058-1}}</ref> Aerosol transmission in such locations has not been ruled out.<ref name=":9" /> [[Medicine:Aerosol-generating procedure|Some medical procedures]] performed on COVID-19 patients in health facilities can generate those smaller droplets,<ref name="pmid22563403">{{cite journal|vauthors=Tran K, Cimon K, Severn M, Pessoa-Silva CL, Conly J|year=2012|title=Aerosol generating procedures and risk of transmission of acute respiratory infections to healthcare workers: a systematic review|journal=PLOS ONE|volume=7|issue=4|pages=e35797|bibcode=2012PLoSO...735797T|doi=10.1371/journal.pone.0035797|pmc=3338532|pmid=22563403}}</ref> and result in the virus being transmitted more easily than normal.<ref name="WHO2020QA" /><ref name="ECDCQA" /> 

When the contaminated droplets fall to floors or surfaces they can, though less commonly, remain infectious if people touch contaminated surfaces and then their eyes, nose or mouth with unwashed hands.<ref name="WHO2020QA" /> On surfaces the amount of viable active virus decreases over time until it can no longer cause infection,<ref name=ECDCQA/> and surfaces are thought not to be the main way the virus spreads.<ref name="CDCTrans" /> It is unknown what amount of virus on surfaces is required to cause infection via this method, but it can be detected for up to four hours on copper, up to one day on cardboard, and up to three days on plastic ([[Chemistry:Polypropylene|polypropylene]]) and [[Chemistry:Stainless steel|stainless steel]] (AISI 304).<ref name=ECDCQA/><ref name="StableNIH">{{cite web|url=https://www.nih.gov/news-events/news-releases/new-coronavirus-stable-hours-surfaces|title=New coronavirus stable for hours on surfaces|date=17 March 2020|publisher=[[Organization:National Institutes of Health|National Institutes of Health]]|url-status=live|archive-url=https://web.archive.org/web/20200323032520/https://www.nih.gov/news-events/news-releases/new-coronavirus-stable-hours-surfaces|archive-date=23 March 2020|access-date=30 April 2020}}</ref><!-- Quote: The scientists found that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was detectable in aerosols for up to three hours, up to four hours on copper, up to twenty-four hours on cardboard and up to two to three days on plastic and stainless steel. --><ref name="Doremalen">{{cite journal | vauthors = van Doremalen N, Bushmaker T, Morris DH, Holbrook MG, Gamble A, Williamson BN, Tamin A, Harcourt JL, Thornburg NJ, Gerber SI, Lloyd-Smith JO, de Wit E, Munster VJ | display-authors = 6 | title = Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1 | journal = New England Journal of Medicine | volume = 382 | issue = 16 | pages = 1564–1567 | date = April 2020 | pmid = 32182409 | pmc = 7121658 | doi = 10.1056/NEJMc2004973 | doi-access = free }}</ref> Surfaces are easily decontaminated with household disinfectants which destroy the virus outside the human body or on the hands.<ref name="WHO2020QA" /> Disinfectants or bleach are not a treatment for COVID‑19, and cause health problems when not used properly, such as when used inside the human body.<ref>{{cite web|title=Household cleaners and disinfectants can cause health problems when not used properly.|url=https://twitter.com/cdcgov/status/1253742258853199872?lang=en |date=24 April 2020|publisher=U.S. Centers for Disease Control and Prevention (CDC) |access-date=6 May 2020}}</ref>

Sputum and [[Biology:Saliva|saliva]] carry large amounts of virus.<ref name="WHO2020QA" /><ref name="CDCTrans" /><ref name=ECDCQA/><ref name="Saliva2020"/> Although COVID‑19 is not a [[Medicine:Sexually transmitted infection|sexually transmitted infection]], direct contact such as kissing, intimate contact, and [[Biology:Fecal–oral route|fecal–oral routes]] are suspected to transmit the virus.<ref>{{cite web|url=https://www.acon.org.au/what-we-are-here-for/covid19/ |title=COVID-19 and Our Communities–ACON–We are a New South Wales based health promotion organisation specialising in HIV prevention, HIV support and lesbian, gay, bisexual, transgender and intersex (LGBTI) health |publisher=Acon.org.au |date= |access-date=29 April 2020}}</ref><ref>{{cite web|url=https://www1.nyc.gov/assets/doh/downloads/pdf/imm/covid-sex-guidance.pdf|title=Sex and Coronavirus Disease 2019 (COVID-19) | date=27 March 2020|website=nyc.gov|url-status=live|archive-url=|archive-date=|access-date=29 April 2020}}</ref> The virus may occur in breast milk, but it's unknown whether it's infectious and transmittable to the baby.<ref>{{cite web |url=https://www.uni-ulm.de/en/med/faculty/med-detailseiten/news-detail/article/moeglicher-uebertragungsweg-von-sars-cov-2-erstmals-neues-coronavirus-in-muttermilch-nachgewiesen-1/ |title=Latest findings by Ulm virologists – New coronavirus detected in breast milk |last=Bingmann |first=Annika | name-list-format = vanc |date=22 May 2020 |access-date=5 June 2020}}</ref><ref>{{cite journal | vauthors = Groß R, Conzelmann C, Müller JA, Stenger S, Steinhart K, Kirchhoff F, Münch J | title = Detection of SARS-CoV-2 in human breastmilk | language = English | journal = Lancet | volume = 0 | issue = 10239 | pages = 1757–1758 | date = May 2020 | pmid = 32446324 | pmc = 7241971 | doi = 10.1016/S0140-6736(20)31181-8 | url = https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)31181-8/fulltext }}</ref>

Estimates of the number of people infected by one person with COVID-19, the [[Medicine:Basic reproduction number|R0]], have varied. The WHO's initial estimates of R0 were 1.4–2.5 (average 1.95), however an early April 2020 review found the ''basic'' R0 (without control measures) to be higher at 3.28 and the median R0 to be 2.79.<ref>{{Cite web|title=Novel Coronavirus—Information for Clinicians|url=https://www.health.gov.au/sites/default/files/documents/2020/03/coronavirus-covid-19-information-for-clinicians.pdf|last=|first=|date=|website=Australian Government Dept of Health|url-status=live|archive-url=|archive-date=|access-date=}}</ref><section end="Transmission" />

===Virology===

{{main|Biology:Severe acute respiratory syndrome coronavirus 2}}
thumb|Illustration of [[SARSr-CoV virion]]

Severe acute respiratory syndrome coronavirus{{nbsp}}2 (SARS-CoV-2) is a [[Biology:Novel virus|novel]] severe acute respiratory syndrome coronavirus, first isolated from three people with pneumonia connected to the [[Medicine:Disease cluster|cluster]] of acute respiratory illness cases in Wuhan.<ref name="ECDC risk assessment">{{cite web |url=https://www.ecdc.europa.eu/sites/default/files/documents/SARS-CoV-2-risk-assessment-14-feb-2020.pdf |title=Outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): increased transmission beyond China—fourth update |publisher=European Centre for Disease Prevention and Control |date=14 February 2020 |access-date=8 March 2020}}</ref> All features of the novel SARS-CoV-2 virus occur in related coronaviruses in nature.<ref name="NM-20200317" />
Outside the human body, the virus is destroyed by household soap, which bursts its [[Biology:Viral envelope|protective bubble]].<ref name=":0"/>

SARS-CoV-2 is closely related to the original SARS-CoV.<ref name="Zhu24Jan2020">{{cite journal | vauthors = Zhu N, Zhang D, Wang W, Li X, Yang B, Song J, Zhao X, Huang B, Shi W, Lu R, Niu P, Zhan F, Ma X, Wang D, Xu W, Wu G, Gao GF, Tan W | display-authors = 6 | title = A Novel Coronavirus from Patients with Pneumonia in China, 2019 | journal = New England Journal of Medicine | volume = 382 | issue = 8 | pages = 727–733 | date = February 2020 | pmid = 31978945 | pmc = 7092803 | doi = 10.1056/NEJMoa2001017 }}</ref> It is thought to have an animal ([[Biology:Zoonosis|zoonotic]]) origin. Genetic analysis has revealed that the coronavirus genetically clusters with the genus ''[[Biology:Betacoronavirus|Betacoronavirus]]'', in subgenus [[Biology:Severe acute respiratory syndrome-related coronavirus|''Sarbecovirus'']] (lineage B) together with two [[Biology:Bat|bat]]-derived strains. It is 96% identical at the whole [[Biology:Genome|genome]] level to other bat coronavirus samples (BatCov RaTG13).<ref name="WHOReport24Feb2020" /> In February 2020, Chinese researchers found that there is only one [[Chemistry:Amino acid|amino acid]] difference in the binding domain of the [[Biology:Peplomer|S protein]] between the coronaviruses from pangolins and those from humans; however, whole-genome comparison to date{{when|date=June 2020}} found that at most 92% of genetic material was shared between pangolin coronavirus and [[Biology:SARS-CoV-2|SARS-CoV-2]], which is insufficient to prove pangolins to be the intermediate host.<ref name="Cyranoski26Feb2020">{{cite journal | vauthors = Cyranoski D | title = Mystery deepens over animal source of coronavirus | journal = Nature | volume = 579 | issue = 7797 | pages = 18–19 | date = March 2020 | pmid = 32127703 | doi = 10.1038/d41586-020-00548-w | doi-access = free | bibcode = 2020Natur.579...18C }}</ref>

==Pathophysiology==

The lungs are the organs most affected by COVID‑19 because the virus accesses host cells via the enzyme [[Biology:Angiotensin-converting enzyme 2|angiotensin-converting enzyme 2]] (ACE2), which is most abundant in type II alveolar cells of the lungs.<ref>{{cite journal | vauthors = Verdecchia P, Cavallini C, Spanevello A, Angeli F | title = The pivotal link between ACE2 deficiency and SARS-CoV-2 infection | journal = European Journal of Internal Medicine | volume = 76 | pages = 14–20 | date = June 2020 | pmid = 32336612 | pmc = 7167588 | doi = 10.1016/j.ejim.2020.04.037 }}</ref> The virus uses a special surface glycoprotein called a "spike" ([[Biology:Peplomer|peplomer]]) to connect to ACE2 and enter the host cell.<ref name="Nature Microbiology">{{cite journal | vauthors = Letko M, Marzi A, Munster V | title = Functional assessment of cell entry and receptor usage for SARS-CoV-2 and other lineage B betacoronaviruses | journal = Nature Microbiology | volume = 5 | issue = 4 | pages = 562–569 | date = April 2020 | pmid = 32094589 | pmc = 7095430 | doi = 10.1038/s41564-020-0688-y | doi-access = free }}</ref> The density of ACE2 in each tissue correlates with the severity of the disease in that tissue and some have suggested decreasing ACE2 activity might be protective,<ref name="Zhang Penninger Li Zhong p.">{{cite journal | vauthors = Zhang H, Penninger JM, Li Y, Zhong N, Slutsky AS | title = Angiotensin-converting enzyme 2 (ACE2) as a SARS-CoV-2 receptor: molecular mechanisms and potential therapeutic target | journal = Intensive Care Medicine | volume = 46 | issue = 4 | pages = 586–590 | date = April 2020 | pmid = 32125455 | pmc = 7079879 | doi = 10.1007/s00134-020-05985-9 | doi-access = free }}</ref><ref name="Xu Zhong Deng Peng p.">{{cite journal | vauthors = Xu H, Zhong L, Deng J, Peng J, Dan H, Zeng X, Li T, Chen Q | display-authors = 6 | title = High expression of ACE2 receptor of 2019-nCoV on the epithelial cells of oral mucosa | journal = International Journal of Oral Science | volume = 12 | issue = 1 | pages = 8 | date = February 2020 | pmid = 32094336 | pmc = 7039956 | doi = 10.1038/s41368-020-0074-x | doi-access = free }}</ref>{{medrs |reason=primary source used to support biomedical claim |sure=yes |date=May 2020}} though another view is that increasing ACE2 using [[Chemistry:Angiotensin II receptor blocker|angiotensin II receptor blocker]] medications could be protective.<ref>{{cite journal | vauthors = Gurwitz D | title = Angiotensin receptor blockers as tentative SARS-CoV-2 therapeutics | journal = Drug Development Research | date = March 2020 | pmid = 32129518 | doi = 10.1002/ddr.21656 | pmc = 7228359 | doi-access = free }}</ref> As the alveolar disease progresses, respiratory failure might develop and death may follow.<ref name="Xu Zhong Deng Peng p." />{{medrs |reason=primary source used to support biomedical claim |sure=yes |date=May 2020}}

SARS-CoV-2 may also cause respiratory failure through affecting the brainstem as other coronaviruses have been found to invade the [[Biology:Central nervous system|central nervous system (CNS)]]. While virus has been detected in cerebrospinal fluid of autopsies, the exact mechanism by which it invades the CNS remains unclear and may first involve invasion of peripheral nerves given the low levels of ACE2 in the brain.<ref>{{cite journal | vauthors = Li YC, Bai WZ, Hashikawa T | title = The neuroinvasive potential of SARS-CoV2 may play a role in the respiratory failure of COVID-19 patients | journal = Journal of Medical Virology | volume = 92 | issue = 6 | pages = 552–555 | date = February 2020 | pmid = 32104915 | doi = 10.1002/jmv.25728 | pmc = 7228394 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Baig AM, Khaleeq A, Ali U, Syeda H | title = Evidence of the COVID-19 Virus Targeting the CNS: Tissue Distribution, Host-Virus Interaction, and Proposed Neurotropic Mechanisms | journal = ACS Chemical Neuroscience | volume = 11 | issue = 7 | pages = 995–998 | date = April 2020 | pmid = 32167747 | pmc = 7094171 | doi = 10.1021/acschemneuro.0c00122 }}</ref>{{medrs |reason=primary source used to support biomedical claim |sure=yes |date=May 2020}}

The virus also affects gastrointestinal organs as ACE2 is abundantly expressed in the glandular cells of [[Biology:Stomach|gastric]], [[Biology:Duodenum|duodenal]] and [[Biology:Rectum|rectal]] [[Biology:Epithelium|epithelium]]<ref name=":11">{{cite journal | vauthors = Gu J, Han B, Wang J | title = COVID-19: Gastrointestinal Manifestations and Potential Fecal-Oral Transmission | journal = Gastroenterology | volume = 158 | issue = 6 | pages = 1518–1519 | date = May 2020 | pmid = 32142785 | pmc = 7130192 | doi = 10.1053/j.gastro.2020.02.054 }}</ref> as well as [[Biology:Endothelium|endothelial]] cells and [[Biology:Enterocyte|enterocyte]]s of the [[Biology:Small intestine|small intestine]].<ref>{{cite journal | vauthors = Hamming I, Timens W, Bulthuis ML, Lely AT, Navis G, van Goor H | title = Tissue distribution of ACE2 protein, the functional receptor for SARS coronavirus. A first step in understanding SARS pathogenesis | journal = The Journal of Pathology | volume = 203 | issue = 2 | pages = 631–7 | date = June 2004 | pmid = 15141377 | pmc = 7167720 | doi = 10.1002/path.1570 }}</ref>{{medrs |reason=primary source used to support biomedical claim |sure=yes |date=May 2020}}

The virus can cause [[Medicine:Myocardial infarction|acute myocardial injury]] and chronic damage to the [[Biology:Circulatory system|cardiovascular system]].<ref name=":3">{{cite journal | vauthors = Zheng YY, Ma YT, Zhang JY, Xie X | title = COVID-19 and the cardiovascular system | journal = Nature Reviews. Cardiology | volume = 17 | issue = 5 | pages = 259–260 | date = May 2020 | pmid = 32139904 | pmc = 7095524 | doi = 10.1038/s41569-020-0360-5 }}</ref> An acute cardiac injury was found in 12% of infected people admitted to the hospital in Wuhan, China,<ref name="Huang24Jan2020"/> and is more frequent in severe disease.<ref>{{cite journal | vauthors = Wang D, Hu B, Hu C, Zhu F, Liu X, Zhang J, Wang B, Xiang H, Cheng Z, Xiong Y, Zhao Y, Li Y, Wang X, Peng Z | display-authors = 6 | title = Clinical Characteristics of 138 Hospitalized Patients With 2019 Novel Coronavirus-Infected Pneumonia in Wuhan, China | journal = JAMA | volume = 323 | issue = 11 | pages = 1061–1069 | date = February 2020 | pmid = 32031570 | pmc = 7042881 | doi = 10.1001/jama.2020.1585 }}</ref>{{medrs |reason=primary source used to support biomedical claim |sure=yes |date=May 2020}} Rates of cardiovascular symptoms are high, owing to the systemic inflammatory response and immune system disorders during disease progression, but acute myocardial injuries may also be related to ACE2 receptors in the heart.<ref name=":3" /> ACE2 receptors are highly expressed in the heart and are involved in heart function.<ref name=":3" /><ref>{{cite journal | vauthors = Turner AJ, Hiscox JA, Hooper NM | title = ACE2: from vasopeptidase to SARS virus receptor | journal = Trends in Pharmacological Sciences | volume = 25 | issue = 6 | pages = 291–4 | date = June 2004 | pmid = 15165741 | pmc = 7119032 | doi = 10.1016/j.tips.2004.04.001 | url = https://www.cell.com/trends/pharmacological-sciences/abstract/S0165-6147(04)00097-5 }}</ref> A high incidence of [[Medicine:Thrombosis|thrombosis]] (31%) and venous thromboembolism (25%) have been found in ICU patients with COVID‑19 infections, and may be related to poor prognosis.<ref name=":4">{{cite journal | vauthors = Klok FA, Kruip MJ, van der Meer NJ, Arbous MS, Gommers DA, Kant KM, Kaptein FH, van Paassen J, Stals MA, Huisman MV, Endeman H | display-authors = 6 | title = Incidence of thrombotic complications in critically ill ICU patients with COVID-19 | journal = Thrombosis Research | date = April 2020 | volume = 191 | pages = 145–147 | pmid = 32291094 | pmc = 7146714 | doi = 10.1016/j.thromres.2020.04.013}}</ref>{{medrs |reason=primary source used to support biomedical claim |sure=yes |date=May 2020}}<ref>{{cite journal |vauthors=Cui S, Chen S, Li X, Liu S, Wang F |title=Prevalence of venous thromboembolism in patients with severe novel coronavirus pneumonia |journal=Journal of Thrombosis and Haemostasis |date=April 2020 |volume=18 |issue=6 |pages=1421–1424 |pmid=32271988 |doi=10.1111/jth.14830 |pmc=7262324 |doi-access=free}}</ref>{{medrs |reason=primary source used to support biomedical claim |sure=yes |date=May 2020}} Blood vessel dysfunction and clot formation (as suggested by high D-dimer levels) are thought to play a significant role in mortality, incidences of clots leading to [[Medicine:Pulmonary embolism|pulmonary embolism]]s, and [[Medicine:Stroke|ischaemic events]] within the brain have been noted as complications leading to death in patients infected with SARS-CoV-2. Infection appears to set off a chain of [[Chemistry:Vasoconstriction|vasoconstrictive responses]] within the body, constriction of blood vessels within the [[Biology:Pulmonary circulation|pulmonary circulation]] has also been posited as a mechanism in which oxygenation decreases alongside the presentation of viral pneumonia.<ref name="Science">{{cite journal |last=Wadman |first=Meredith |name-list-format=vanc |doi=10.1126/science.abc3208 |title=How does coronavirus kill? Clinicians trace a ferocious rampage through the body, from brain to toes |journal=Science |date=April 2020 |doi-access=free}}</ref>{{better source |reason=popsci source used to support biomedical claim |date=May 2020}}

Another common cause of death is complications related to the kidneys.<ref name="Science"/>{{better source |reason=popsci source used to support biomedical claim |date=May 2020}} Early reports show that up to 30% of hospitalized patients in both China and New York have experienced some injury to their kidneys, including some persons with no previous kidney problems.<ref>[https://www.hopkinsmedicine.org/health/conditions-and-diseases/coronavirus/coronavirus-kidney-damage-caused-by-covid19 Coronavirus: Kidney Damage Caused by COVID-19], ''Johns Hopkins Medicine'', C. John Sperati, updated 14 May 2020.</ref>

Autopsies of people who died of COVID‑19 have found diffuse alveolar damage (DAD), and lymphocyte-containing inflammatory infiltrates within the lung.<ref name="AJCPCOVID">{{cite journal |vauthors=Barton LM, Duval EJ, Stroberg E, Ghosh S, Mukhopadhyay S |title=COVID-19 Autopsies, Oklahoma, USA |journal=[[Medicine:American Journal of Clinical Pathology|American Journal of Clinical Pathology]] |volume=153 |issue=6 |pages=725–733 |date=May 2020 |pmid=32275742 |pmc=7184436 |doi=10.1093/ajcp/aqaa062}}</ref>{{medrs |reason=primary source (case report) used to support biomedical claim |sure=yes |date=May 2020}}

===Immunopathology===

Although SARS-CoV-2 has a tropism for ACE2-expressing epithelial cells of the respiratory tract, patients with severe COVID‑19 have symptoms of systemic hyperinflammation. Clinical laboratory findings of elevated [[Biology:Interleukin 2|IL-2]], [[Medicine:Interleukin 7|IL-7]], IL-6, [[Chemistry:Granulocyte-macrophage colony-stimulating factor|granulocyte-macrophage colony-stimulating factor]] (GM-CSF), [[Biology:CXCL10|interferon-γ inducible protein 10]] (IP-10), monocyte chemoattractant protein{{nbsp}}1 (MCP-1), [[Biology:Macrophage inflammatory protein|macrophage inflammatory protein 1-α]] (MIP-1α), and [[Biology:Tumor necrosis factor alpha|tumour necrosis factor-α]] (TNF-α) indicative of [[Medicine:Cytokine release syndrome|cytokine release syndrome]] (CRS) suggest an underlying immunopathology.<ref name="Huang24Jan2020"/>

Additionally, people with COVID‑19 and [[Medicine:Acute respiratory distress syndrome|acute respiratory distress syndrome]] (ARDS) have classical [[Biology:Serum (blood)|serum]] [[Medicine:Biomarker|biomarker]]s of CRS, including elevated [[Chemistry:C-reactive protein|C-reactive protein]] (CRP), [[Biology:Lactate dehydrogenase|lactate dehydrogenase]] (LDH), [[Chemistry:D-dimer|D-dimer]], and [[Biology:Ferritin|ferritin]].<ref>{{cite journal | vauthors = Zhang C, Wu Z, Li JW, Zhao H, Wang GQ | title = The cytokine release syndrome (CRS) of severe COVID-19 and Interleukin-6 receptor (IL-6R) antagonist Tocilizumab may be the key to reduce the mortality | journal = International Journal of Antimicrobial Agents | pages = 105954 | date = March 2020 | volume = 55 | issue = 5 | pmid = 32234467 | pmc = 7118634 | doi = 10.1016/j.ijantimicag.2020.105954 }}</ref>

Systemic inflammation results in [[Medicine:Vasodilation|vasodilation]], allowing inflammatory lymphocytic and monocytic infiltration of the lung and the heart. In particular, pathogenic GM-CSF-secreting T-cells were shown to correlate with the recruitment of inflammatory IL-6-secreting [[Biology:Monocyte|monocyte]]s and severe lung pathology in COVID‑19 patients.{{citation needed|date=May 2020}} Lymphocytic infiltrates have also been reported at autopsy.<ref name="AJCPCOVID"/>{{medrs |reason=primary source (case report) used to support biomedical claim |sure=yes |date=May 2020}}

==Diagnosis==

[[file:Infektionsschutzzentrum im Rautenstrauch-Joest-Museum, Köln-6313 (cropped).jpg|thumb|Demonstration of a [[Nasopharyngeal swab|nasopharyngeal swab]] for COVID-19 testing]]
thumb|[[Centers for Disease Control and Prevention|US CDC rRT-PCR test kit for COVID-19<ref>{{cite web |url=https://www.cdc.gov/coronavirus/2019-ncov/about/testing.html |title=CDC Tests for 2019-nCoV |author= |date=5 February 2020 |website=U.S. Centers for Disease Control and Prevention |url-status=live |archive-url=https://web.archive.org/web/20200214023335/https://www.cdc.gov/coronavirus/2019-ncov/about/testing.html |archive-date=14 February 2020 |access-date=12 February 2020 |name-list-format=vanc}}</ref>]]

The WHO has published several testing protocols for the disease.<ref>{{cite web|url=https://www.who.int/publications-detail/laboratory-testing-for-2019-novel-coronavirus-in-suspected-human-cases-20200117|title=Laboratory testing for 2019 novel coronavirus (2019-nCoV) in suspected human cases|website=[[Organization:World Health Organization|World Health Organization]] (WHO)|access-date=13 March 2020|archive-url=https://web.archive.org/web/20200317023052/https://www.who.int/publications-detail/laboratory-testing-for-2019-novel-coronavirus-in-suspected-human-cases-20200117|archive-date=17 March 2020|url-status=live}}</ref> The standard method of testing is real-time reverse transcription polymerase chain reaction (rRT-PCR).<ref name="20200130cdc">{{cite web |url=https://www.cdc.gov/coronavirus/2019-ncov/summary.html |title=2019 Novel Coronavirus (2019-nCoV) Situation Summary |date=30 January 2020 |website=U.S. Centers for Disease Control and Prevention (CDC) |url-status=live |archive-url=https://web.archive.org/web/20200126210549/https://www.cdc.gov/coronavirus/2019-nCoV/summary.html |archive-date=26 January 2020 |access-date=30 January 2020| name-list-format = vanc}}</ref> The test is typically done on respiratory samples obtained by a [[Nasopharyngeal swab|nasopharyngeal swab]]; however, a nasal swab or sputum sample may also be used.<ref name="CDC2020Testing"/><ref name="20200129cdc">{{cite web |url=https://www.cdc.gov/coronavirus/2019-ncov/lab/rt-pcr-detection-instructions.html |title=Real-Time RT-PCR Panel for Detection 2019-nCoV |date=29 January 2020 |website=U.S. Centers for Disease Control and Prevention (CDC) |access-date=1 February 2020 |archive-url=https://web.archive.org/web/20200130202031/https://www.cdc.gov/coronavirus/2019-ncov/lab/rt-pcr-detection-instructions.html |archive-date=30 January 2020 |url-status=live | name-list-format = vanc}}</ref> Results are generally available within a few hours to two days.<ref name="globenewswire1977226">{{cite web |url=https://www.globenewswire.com/news-release/2020/01/30/1977226/0/en/Curetis-Group-Company-Ares-Genetics-and-BGI-Group-Collaborate-to-Offer-Next-Generation-Sequencing-and-PCR-based-Coronavirus-2019-nCoV-Testing-in-Europe.html |title=Curetis Group Company Ares Genetics and BGI Group Collaborate to Offer Next-Generation Sequencing and PCR-based Coronavirus (2019-nCoV) Testing in Europe |date=30 January 2020 |website=GlobeNewswire News Room |access-date=1 February 2020 |archive-url=https://web.archive.org/web/20200131201626/https://www.globenewswire.com/news-release/2020/01/30/1977226/0/en/Curetis-Group-Company-Ares-Genetics-and-BGI-Group-Collaborate-to-Offer-Next-Generation-Sequencing-and-PCR-based-Coronavirus-2019-nCoV-Testing-in-Europe.html |archive-date=31 January 2020 |url-status=live | name-list-format = vanc}}</ref><ref name="20200130businessinsider">{{cite web |url=https://www.businessinsider.com/how-to-know-if-you-have-the-coronavirus-pcr-test-2020-1 |title=There's only one way to know if you have the coronavirus, and it involves machines full of spit and mucus |last=Brueck |first=Hilary | name-list-format = vanc |date=30 January 2020 |website=Business Insider |access-date=1 February 2020 |archive-url= https://web.archive.org/web/20200201034232/https://www.businessinsider.com/how-to-know-if-you-have-the-coronavirus-pcr-test-2020-1 |archive-date=1 February 2020 |url-status=live }}</ref> Blood tests can be used, but these require two blood samples taken two weeks apart, and the results have little immediate value.<ref>{{cite web |url=https://www.who.int/publications-detail/laboratory-testing-for-2019-novel-coronavirus-in-suspected-human-cases-20200117 |title=Laboratory testing for 2019 novel coronavirus (2019-nCoV) in suspected human cases |access-date=26 February 2020 |archive-url=https://web.archive.org/web/20200221192745/https://www.who.int/publications-detail/laboratory-testing-for-2019-novel-coronavirus-in-suspected-human-cases-20200117 |archive-date=21 February 2020 |url-status=live }}</ref> Chinese scientists were able to isolate a strain of the coronavirus and publish the [[Biology:Nucleic acid sequence|genetic sequence]] so laboratories across the world could independently develop [[Biology:Polymerase chain reaction|polymerase chain reaction]] (PCR) tests to detect infection by the virus.<ref name="Hui14Jan2020" /><ref name="Cohen17Jan20202">{{cite journal | vauthors = Cohen J, Normile D | s2cid = 210701594 | title = New SARS-like virus in China triggers alarm | journal = Science | volume = 367 | issue = 6475 | pages = 234–235 | date = January 2020 | pmid = 31949058 | doi = 10.1126/science.367.6475.234 | url = https://mcb.uconn.edu/wp-content/uploads/sites/2341/2020/01/WuhanScience24Jan2020.pdf | access-date = 11 February 2020 | url-status = live | bibcode = 2020Sci...367..234C | archive-url = https://web.archive.org/web/20200211230310/https://mcb.uconn.edu/wp-content/uploads/sites/2341/2020/01/WuhanScience24Jan2020.pdf | archive-date = 11 February 2020 }}</ref><ref name="ncbiWuhanGenomes">{{cite web |url=https://www.ncbi.nlm.nih.gov/labs/virus/vssi/#/virus?SeqType_s=Nucleotide&VirusLineage_ss=Wuhan%20seafood%20market%20pneumonia%20virus,%20taxid:2697049 |title=Severe acute respiratory syndrome coronavirus 2 data hub |website=NCBI |url-status=live |access-date=4 March 2020 |name-list-format=vanc |archive-url=https://web.archive.org/web/20200321235550/https://www.ncbi.nlm.nih.gov/labs/virus/vssi/#/virus?SeqType_s=Nucleotide&VirusLineage_ss=Wuhan%20seafood%20market%20pneumonia%20virus,%20taxid:2697049 |archive-date=21 March 2020 }}</ref> {{As of|2020|April|4}}, antibody tests (which may detect active infections and whether a person had been infected in the past) were in development, but not yet widely used.<ref>{{cite journal | vauthors = Petherick A | title = Developing antibody tests for SARS-CoV-2 | journal = Lancet | volume = 395 | issue = 10230 | pages = 1101–1102 | date = April 2020 | pmid = 32247384 | doi = 10.1016/s0140-6736(20)30788-1 | pmc = 7270070 | doi-access = free }}</ref><ref name="Vogel2020">{{cite journal |title=New blood tests for antibodies could show true scale of coronavirus pandemic |last=Vogel| first=Gretchen | name-list-format = vanc |journal=Science |doi=10.1126/science.abb8028|date=March 2020 |doi-access=free }}</ref><ref>{{cite journal | vauthors = Pang J, Wang MX, Ang IY, Tan SH, Lewis RF, Chen JI, Gutierrez RA, Gwee SX, Chua PE, Yang Q, Ng XY, Yap RK, Tan HY, Teo YY, Tan CC, Cook AR, Yap JC, Hsu LY | display-authors = 6 | title = Potential Rapid Diagnostics, Vaccine and Therapeutics for 2019 Novel Coronavirus (2019-nCoV): A Systematic Review | journal = Journal of Clinical Medicine | volume = 9 | issue = 3 | pages = 623 | date = February 2020 | pmid = 32110875 | pmc = 7141113 | doi = 10.3390/jcm9030623 | doi-access = free }}</ref> Antibody tests may be most accurate 2–3 weeks after a person's symptoms start.<ref>{{Cite journal|last=Deeks|first=Jonathan J.|last2=Dinnes|first2=Jacqueline|last3=Takwoingi|first3=Yemisi|last4=Davenport|first4=Clare|last5=Spijker|first5=René|last6=Taylor-Phillips|first6=Sian|last7=Adriano|first7=Ada|last8=Beese|first8=Sophie|last9=Dretzke|first9=Janine|last10=Ferrante di Ruffano|first10=Lavinia|last11=Harris|first11=Isobel M.|date=June 25, 2020|title=Antibody tests for identification of current and past infection with SARS-CoV-2|url=https://www.ncbi.nlm.nih.gov/pubmed/32584464|journal=The Cochrane Database of Systematic Reviews|volume=6|pages=CD013652|doi=10.1002/14651858.CD013652|issn=1469-493X|pmid=32584464|via=}}</ref> The Chinese experience with testing has shown the [[Sensitivity and specificity|accuracy]] is only 60 to 70%.<ref>AFP News Agency (11 April 2020). "How false negatives are complicating COVID-19 testing". [https://www.aljazeera.com/news/2020/04/false-negatives-complicating-covid-19-testing-200411100741669.html Al Jazeera website] Retrieved 12 April 2020.</ref> The US [[Organization:Food and Drug Administration|Food and Drug Administration]] (FDA) approved the first [[Medicine:Point-of-care testing|point-of-care test]] on 21 March 2020 for use at the end of that month.<ref>{{cite press release |title= Coronavirus (COVID-19) Update: FDA Issues first Emergency Use Authorization for Point of Care Diagnostic |date= 21 March 2020 |publisher= U.S. [[Organization:Food and Drug Administration|Food and Drug Administration]] (FDA) |url= https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-issues-first-emergency-use-authorization-point-care-diagnostic |access-date= 22 March 2020 |archive-url= https://web.archive.org/web/20200321224700/https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-issues-first-emergency-use-authorization-point-care-diagnostic |archive-date= 21 March 2020 |url-status= live }}</ref> The absence or presence of COVID-19 signs and symptoms alone is not reliable enough for an accurate diagnosis.<ref>{{Cite journal|last=Struyf|first=Thomas|last2=Deeks|first2=Jonathan J.|last3=Dinnes|first3=Jacqueline|last4=Takwoingi|first4=Yemisi|last5=Davenport|first5=Clare|last6=Leeflang|first6=Mariska Mg|last7=Spijker|first7=René|last8=Hooft|first8=Lotty|last9=Emperador|first9=Devy|last10=Dittrich|first10=Sabine|last11=Domen|first11=Julie|date=2020|title=Signs and symptoms to determine if a patient presenting in primary care or hospital outpatient settings has COVID-19 disease|url=https://www.ncbi.nlm.nih.gov/pubmed/32633856|journal=The Cochrane Database of Systematic Reviews|volume=7|pages=CD013665|doi=10.1002/14651858.CD013665|issn=1469-493X|pmid=32633856|via=}}</ref>

Diagnostic guidelines released by Zhongnan Hospital of Wuhan University suggested methods for detecting infections based upon clinical features and epidemiological risk. These involved identifying people who had at least two of the following symptoms in addition to a history of travel to Wuhan or contact with other infected people: fever, imaging features of pneumonia, normal or reduced white blood cell count, or reduced [[Biology:Lymphocyte|lymphocyte]] count.<ref name="Jin2020">{{cite journal | vauthors = Jin YH, Cai L, Cheng ZS, Cheng H, Deng T, Fan YP, Fang C, Huang D, Huang LQ, Huang Q, Han Y, Hu B, Hu F, Li BH, Li YR, Liang K, Lin LK, Luo LS, Ma J, Ma LL, Peng ZY, Pan YB, Pan ZY, Ren XQ, Sun HM, Wang Y, Wang YY, Weng H, Wei CJ, Wu DF, Xia J, Xiong Y, Xu HB, Yao XM, Yuan YF, Ye TS, Zhang XC, Zhang YW, Zhang YG, Zhang HM, Zhao Y, Zhao MJ, Zi H, Zeng XT, Wang YY, Wang XH | display-authors = 6 | title = A rapid advice guideline for the diagnosis and treatment of 2019 novel coronavirus (2019-nCoV) infected pneumonia (standard version) | journal = Military Medical Research | volume = 7 | issue = 1 | pages = 4 | date = February 2020 | pmid = 32029004 | pmc = 7003341 | doi = 10.1186/s40779-020-0233-6 | doi-access = free }}</ref>

A study asked hospitalised COVID‑19 patients to cough into a sterile container, thus producing a saliva sample, and detected the virus in eleven of twelve patients using RT-PCR. This technique has the potential of being quicker than a swab and involving less risk to health care workers (collection at home or in the car).<ref name="Saliva2020">{{cite journal | vauthors = To KK, Tsang OT, Chik-Yan Yip C, Chan KH, Wu TC, Chan JM, Leung WS, Chik TS, Choi CY, Kandamby DH, Lung DC, Tam AR, Poon RW, Fung AY, Hung IF, Cheng VC, Chan JF, Yuen KY | display-authors = 6 | title = Consistent detection of 2019 novel coronavirus in saliva | journal = Clinical Infectious Diseases | date = February 2020 | pmid = 32047895 | pmc = 7108139 | doi = 10.1093/cid/ciaa149 | publisher = Oxford University Press | }}</ref><!-- from "Consistent Detection of 2019 Novel Coronavirus in Saliva", 12 February 2020: "Each saliva specimen was inoculated in duplicate; one tube contained tosylsulfonyl phenylalanyl chloromethyl [[Chemistry:Ketone|ketone]]-treated [[Biology:Trypsin|trypsin]] (0.5 μg/mL) in serum-free MEM and the other tube contained MEM with 1% fetal calf serum{{nbsp}}... Virus-induced cytopathic effect was examined daily for up to seven days{{nbsp}}... The median viral load of the first available saliva specimens was 3.3 × 10^6 copies/mL (range, 9.9 × 10^2 to 1.2 × 10^8 copies/mL)." -->

Along with laboratory testing, chest CT scans may be helpful to diagnose COVID‑19 in individuals with a high clinical suspicion of infection but are not recommended for routine screening.<ref name=":0" /><ref name="acr.org"/> Bilateral multilobar ground-glass opacities with a peripheral, asymmetric, and posterior distribution are common in early infection.<ref name=":0" /> Subpleural dominance, [[Medicine:Crazy paving|crazy paving]] (lobular septal thickening with variable alveolar filling), and [[Medicine:Pulmonary consolidation|consolidation]] may appear as the disease progresses.<ref name=":0" /><ref>{{cite journal | vauthors = Lee EY, Ng MY, Khong PL | title = COVID-19 pneumonia: what has CT taught us? | journal = The Lancet. Infectious Diseases | volume = 20 | issue = 4 | pages = 384–385 | date = April 2020 | pmid = 32105641 | pmc = 7128449 | doi = 10.1016/S1473-3099(20)30134-1 | url = https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30134-1/fulltext | access-date = 13 March 2020 | url-status = live | archive-url = https://web.archive.org/web/20200308143943/https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30134-1/fulltext | archive-date = 8 March 2020 }}</ref>

In late 2019, the WHO assigned emergency [[Medicine:ICD-10|ICD-10]] disease codes [[Medicine:ICD-10 Chapter XXII: Codes for special purposes|U07.1]] for deaths from lab-confirmed SARS-CoV-2 infection and U07.2 for deaths from clinically or epidemiologically diagnosed COVID‑19 without lab-confirmed SARS-CoV-2 infection.<ref name="ICD10_2019_U07p2">{{cite web | title = ICD-10 Version:2019 | website = [[Organization:World Health Organization|World Health Organization]] | quote = U07.2—COVID-19, virus not identified—COVID-19 NOS—Use this code when COVID-19 is diagnosed clinically or epidemiologically but laboratory testing is inconclusive or not available. Use additional code, if desired, to identify pneumonia or other manifestations | year = 2019 | url = https://icd.who.int/browse10/2019/en#/U07.1 | access-date = 31 March 2020 | archive-url = https://archive.today/20200331004754/https://icd.who.int/browse10/2019/en%23/U07.1#/U07.1 | archive-date = 31 March 2020 | url-status = live | url-access = <!-- (subscription/registration/limited) default=free -->}}</ref>
{{Multiple image
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|image1=COVID19CT2.webp| caption1= Typical CT imaging findings
|image2=COVID19CT1.webp|caption2=CT imaging of rapid progression stage
}}

===Pathology===

Few data are available about microscopic lesions and the pathophysiology of COVID‑19.<ref>{{cite journal | vauthors = Hanley B, Lucas SB, Youd E, Swift B, Osborn M | title = Autopsy in suspected COVID-19 cases | journal = Journal of Clinical Pathology | volume = 73 | issue = 5 | pages = 239–242 | date = May 2020 | pmid = 32198191 | doi = 10.1136/jclinpath-2020-206522 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Yao XH, Li TY, He ZC, Ping YF, Liu HW, Yu SC, Mou HM, Wang LH, Zhang HR, Fu WJ, Luo T, Liu F, Chen C, Xiao HL, Guo HT, Lin S, Xiang DF, Shi Y, Li QR, Huang X, Cui Y, Li XZ, Tang W, Pan PF, Huang XQ, Ding YQ, Bian XW | s2cid = 212729698 | display-authors = 6 | title = [A pathological report of three COVID-19 cases by minimally invasive autopsies] | language = Chinese | journal = Zhonghua Bing Li Xue Za Zhi = Chinese Journal of Pathology | volume = 49 | pages = 411–417 | date = March 2020 | issue = 5 | pmid = 32172546 | doi = 10.3760/cma.j.cn112151-20200312-00193 }}</ref> The main pathological findings at autopsy are:{{citation needed|date=June 2020}}
* [[Physics:Macroscopic scale|Macroscopy]]: [[Medicine:Pleurisy|pleurisy]], [[Medicine:Pericarditis|pericarditis]], lung consolidation and pulmonary oedema
* Four types of severity of [[Medicine:Viral pneumonia|viral pneumonia]] can be observed:
** minor [[Medicine:Pneumonia|pneumonia]]: minor serous [[Biology:Exudate|exudation]], minor [[Biology:Fibrin|fibrin]] exudation
** mild pneumonia: pulmonary oedema, pneumocyte [[Medicine:Hyperplasia|hyperplasia]], large atypical pneumocytes, interstitial [[Medicine:Inflammation|inflammation]] with lymphocytic [[Medicine:Infiltration (medical)|infiltration]] and [[Biology:Giant cell|multinucleated giant cell]] formation
** severe pneumonia: [[Medicine:Diffuse alveolar damage|diffuse alveolar damage]] (DAD) with diffuse alveolar exudates. DAD is the cause of [[Medicine:Acute respiratory distress syndrome|acute respiratory distress syndrome]] (ARDS) and severe [[Medicine:Hypoxemia|hypoxemia]].
** healing pneumonia: [[Biology:Healing|organisation]] of [[Biology:Exudate|exudate]]s in alveolar cavities and [[Medicine:Pulmonary fibrosis|pulmonary interstitial fibrosis]]
** [[Biology:Plasma cell|plasmocytosis]] in [[Medicine:Bronchoalveolar lavage|BAL]]<ref>{{cite journal | vauthors = Giani M, Seminati D, Lucchini A, Foti G, Pagni F | title = Exuberant Plasmocytosis in Bronchoalveolar Lavage Specimen of the First Patient Requiring Extracorporeal Membrane Oxygenation for SARS-CoV-2 in Europe | journal = Journal of Thoracic Oncology | volume = 15 | issue = 5 | pages = e65–e66 | date = May 2020 | pmid = 32194247 | pmc = 7118681 | doi = 10.1016/j.jtho.2020.03.008 }}</ref>
* [[Biology:Blood|Blood]]: [[Medicine:Disseminated intravascular coagulation|disseminated intravascular coagulation]] (DIC);<ref>{{cite journal | vauthors = Lillicrap D | title = Disseminated intravascular coagulation in patients with 2019-nCoV pneumonia | journal = Journal of Thrombosis and Haemostasis | volume = 18 | issue = 4 | pages = 786–787 | date = April 2020 | pmid = 32212240 | pmc = 7166410 | doi = 10.1111/jth.14781 }}</ref> leukoerythroblastic reaction<ref>{{cite journal | vauthors = Mitra A, Dwyre DM, Schivo M, Thompson GR, Cohen SH, Ku N, Graff JP | title = Leukoerythroblastic reaction in a patient with COVID-19 infection | journal = American Journal of Hematology | date = March 2020 | pmid = 32212392 | doi = 10.1002/ajh.25793 | pmc = 7228283 | doi-access = free }}</ref>
* [[Biology:Liver|Liver]]: microvesicular [[Medicine:Steatosis|steatosis]]{{citation needed|date=May 2020}}

==Prevention==
[[File:20200609 Effect of pandemic containment measures.gif|thumb|upright=1.5| Without pandemic containment measures—such as social distancing, vaccination, and use of face masks—pathogens can spread exponentially.<ref name=Science_20200515>{{cite journal |last1=Maier |first1=Benjamin F. |last2=Brockmann |first2=Dirk |title=Effective containment explains subexponential growth in recent confirmed COVID-19 cases in China |journal=Science |date=15 May 2020 |volume=368 |issue=6492 |pages=742–746 |doi=10.1126/science.abb4557 |pmid=32269067 |pmc=7164388 |bibcode=2020Sci...368..742M }} ("...initial exponential growth expected for an unconstrained outbreak.")</ref> This graphic shows how early adoption of containment measures tends to protect wider swaths of the population.]]
thumb|upright=1.5|Progressively stronger mitigation efforts to reduce the number of active cases at any given time—"[[flattening the curve"—allows healthcare services to better manage the same volume of patients.<ref>{{cite web |last=Wiles |first=Siouxsie | name-list-format = vanc |title=The three phases of Covid-19—and how we can make it manageable |url=https://thespinoff.co.nz/society/09-03-2020/the-three-phases-of-covid-19-and-how-we-can-make-it-manageable/ |website=The Spinoff |access-date=9 March 2020 |date=9 March 2020 |archive-url=https://web.archive.org/web/20200327120015/https://thespinoff.co.nz/society/09-03-2020/the-three-phases-of-covid-19-and-how-we-can-make-it-manageable/ |archive-date=27 March 2020 |url-status=live }}</ref><ref name="Lancet2020Flatten">{{cite journal | vauthors = Anderson RM, Heesterbeek H, Klinkenberg D, Hollingsworth TD | title = How will country-based mitigation measures influence the course of the COVID-19 epidemic? | journal = Lancet | volume = 395 | issue = 10228 | pages = 931–934 | date = March 2020 | pmid = 32164834 | pmc = 7158572 | doi = 10.1016/S0140-6736(20)30567-5 | quote = A key issue for epidemiologists is helping policy makers decide the main objectives of mitigation—e.g. minimising morbidity and associated mortality, avoiding an epidemic peak that overwhelms health-care services, keeping the effects on the economy within manageable levels, and flattening the epidemic curve to wait for vaccine development and manufacture on scale and antiviral drug therapies. | doi-access = free }}</ref><ref>{{cite web|url=https://www.vox.com/2020/3/10/21171481/coronavirus-us-cases-quarantine-cancellation|title=How canceled events and self-quarantines save lives, in one chart|first=Eliza|last=Barclay| name-list-format = vanc |date=10 March 2020|website=Vox|access-date=12 March 2020|archive-url=https://web.archive.org/web/20200312161852/https://www.vox.com/2020/3/10/21171481/coronavirus-us-cases-quarantine-cancellation|archive-date=12 March 2020|url-status=live}}</ref> Likewise, progressively greater increases in healthcare capacity—called ''raising the line''—such as by increasing bed count, personnel, and equipment, helps to meet increased demand.<ref name="Vox_20200407">{{cite web |last1=Barclay |first1=Eliza |last2=Scott |first2=Dylan |last3=Animashaun |first3=Animashaun | name-list-format = vanc |title=The US doesn't just need to flatten the curve. It needs to "raise the line." |url=https://www.vox.com/2020/4/7/21201260/coronavirus-usa-chart-mask-shortage-ventilators-flatten-the-curve |work=Vox |date=7 April 2020 |archive-url=https://web.archive.org/web/20200407155950/https://www.vox.com/2020/4/7/21201260/coronavirus-usa-chart-mask-shortage-ventilators-flatten-the-curve |archive-date=7 April 2020 |url-status=live }}</ref>]]
thumb|upright=1.5|Mitigation attempts that are inadequate in strictness or duration—such as premature relaxation of distancing rules or stay-at-home orders—can allow a resurgence after the initial surge and mitigation.<ref name="Lancet2020Flatten"/><ref name="Wiles">{{cite web |last=Wiles |first=Siouxsie | name-list-format = vanc |title=After 'Flatten the Curve', we must now 'Stop the Spread'. Here's what that means |url=https://thespinoff.co.nz/society/14-03-2020/after-flatten-the-curve-we-must-now-stop-the-spread-heres-what-that-means/ |website=The Spinoff |access-date=13 March 2020 |date=14 March 2020 |archive-url=https://web.archive.org/web/20200326232315/https://thespinoff.co.nz/society/14-03-2020/after-flatten-the-curve-we-must-now-stop-the-spread-heres-what-that-means/ |archive-date=26 March 2020 |url-status=live }}</ref>

A [[Medicine:COVID-19 vaccine|COVID-19 vaccine]] is not expected until 2021 at the earliest.<ref>{{cite web | url = https://www.sciencealert.com/who-says-a-coronavirus-vaccine-is-18-months-away | title = Here's Why It's Taking So Long to Develop a Vaccine for the New Coronavirus | website = Science Alert | first1 = Rob | last1 = Grenfell | first2 = Trevor | last2 = Drew | name-list-format = vanc | date = 17 February 2020 | access-date = 26 February 2020 | archive-url = https://web.archive.org/web/20200228010631/https://www.sciencealert.com/who-says-a-coronavirus-vaccine-is-18-months-away | archive-date = 28 February 2020 | url-status = live }}</ref> The US [[Organization:National Institutes of Health|National Institutes of Health]] guidelines do not recommend any medication for prevention of COVID‑19, before or after exposure to the SARS-CoV-2 virus, outside the setting of a clinical trial.<ref name="NIHGuidelines2020"/><ref name="Sanders20202" /> Without a vaccine, other prophylactic measures, or effective treatments, a key part of managing COVID‑19 is trying to decrease and delay the epidemic peak, known as "flattening the [[Epidemic curve|curve]]".<ref name="Lancet2020Flatten" /> This is done by slowing the infection rate to decrease the risk of health services being overwhelmed, allowing for better treatment of current cases, and delaying additional cases until effective treatments or a vaccine become available.<ref name="Lancet2020Flatten" /><ref name="Wiles"/>

Preventive measures to reduce the chances of infection include staying at home, wearing a mask in public, avoiding crowded places, keeping distance from others, washing hands with soap and water often and for at least 20 seconds, practising good respiratory hygiene, and avoiding touching the eyes, nose, or mouth with unwashed hands.<ref name="CDC042020">{{cite web|date=28 June 2020|title=Recommendation Regarding the Use of Cloth Face Coverings, Especially in Areas of Significant Community-Based Transmission|work=U.S. Centers for Disease Control and Prevention (CDC) |url=https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover.html|url-status=live|access-date=}}</ref><ref name="CDC-Prevention & Treatment">{{cite web | url = https://www.cdc.gov/coronavirus/about/prevention.html | vauthors = ((Centers for Disease Control and Prevention)) | title = Coronavirus Disease 2019 (COVID-19): Prevention & Treatment | date = 3 February 2020 | access-date = 10 February 2020 | archive-url = https://web.archive.org/web/20191215193934/https://www.cdc.gov/coronavirus/about/prevention.html | archive-date = 15 December 2019 | url-status = live| author-link = Centers for Disease Control and Prevention] }}</ref><ref name="WHO Advice for Public">{{cite web | url = https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public | title = Advice for Public | vauthors = ((World Health Organization)) | access-date = 10 February 2020 | archive-url = https://web.archive.org/web/20200126025750/https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public | archive-date = 26 January 2020 | url-status = live| author-link = World Health Organization | name-list-format = vanc}}</ref><ref>{{cite web|url=https://www.npr.org/sections/goatsandsoda/2020/03/17/814221111/my-hand-washing-song-readers-offer-lyrics-for-a-20-second-scrub|title=My Hand-Washing Song: Readers Offer Lyrics For A 20-Second Scrub|website=NPR.org|access-date=20 March 2020|archive-url=https://web.archive.org/web/20200320145553/https://www.npr.org/sections/goatsandsoda/2020/03/17/814221111/my-hand-washing-song-readers-offer-lyrics-for-a-20-second-scrub|archive-date=20 March 2020|url-status=live}}</ref>

The US Centers for Disease Control and Prevention (CDC) and the [[Organization:World Health Organization|World Health Organization]] (WHO) recommend individuals wear non-medical face coverings in public settings where there is an increased risk of transmission and where social distancing measures are difficult to maintain.<ref>{{Cite news|date=2020-06-05|title=Wear masks in public says WHO, in update of COVID-19 advice|work=Reuters|url=https://www.reuters.com/article/us-health-coronavirus-who-masks-idUSKBN23C27Y|access-date=2020-07-03}}</ref><ref name=":2"/><ref>{{Cite web|last=|first=|date=|title=When and how to use masks|url=https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public/when-and-how-to-use-masks|url-status=live|archive-url=|archive-date=|access-date=2020-07-03|website=WHO}}</ref> This recommendation is meant to reduce the spread of the disease by asymptomatic and pre-symtomatic individuals and is complementary to established preventive measures such as social distancing.<ref name=":2" /><ref name=":5">{{cite web|last=|date=8 April 2020|title=Using face masks in the community—Technical Report|url=https://www.ecdc.europa.eu/sites/default/files/documents/COVID-19-use-face-masks-community.pdf|url-status=live|archive-url=|archive-date=|access-date=|website=ECDC}}</ref> Face coverings limit the volume and travel distance of expiratory droplets dispersed when talking, breathing, and coughing.<ref name=":2" /><ref name=":5" /> Many countries and local jurisdictions encourage or mandate the use of face masks or cloth face coverings by members of the public to limit the spread of the virus.<ref name="NewshubMasks">{{cite news |title=Which countries have made wearing face masks compulsory? |url=https://www.aljazeera.com/news/2020/04/countries-wearing-face-masks-compulsory-200423094510867.html |publisher=Al Jazeera |date=2020-05-20}}</ref><ref>{{cite web|title=Recommendation Regarding the Use of Cloth Face Coverings, Especially in Areas of Significant Community-Based Transmission|url=https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover.html|date=2020-02-11|website=U.S. Centers for Disease Control and Prevention (CDC)|access-date=2020-04-17}}</ref><ref name="nhc_masks">{{cite web|date=7 February 2020|title=For different groups of people: how to choose masks|url=http://en.nhc.gov.cn/2020-02/07/c_76337.htm|archive-url=|archive-date=|access-date=22 March 2020|work=NHC.gov.cn|publisher=National Health Commission of the People's Republic of China|quote="Disposable medical masks: Recommended for: · People in crowded places · Indoor working environment with a relatively dense population · People going to medical institutions · Children in kindergarten and students at school gathering to study and do other activities"}}</ref><ref>{{cite journal | vauthors = Greenhalgh T, Schmid MB, Czypionka T, Bassler D, Gruer L | s2cid = 215516381 | title = Face masks for the public during the covid-19 crisis | journal = BMJ | volume = 369 | pages = m1435 | date = April 2020 | pmid = 32273267 | doi = 10.1136/bmj.m1435 | url = https://www.bmj.com/content/369/bmj.m1435.short }}</ref>

Masks are also strongly recommended for those who may have been infected and those taking care of someone who may have the disease.<ref>{{Cite web|last=CDC|date=2020-02-11|title=Caring for Someone Sick at Home|url=https://www.cdc.gov/coronavirus/2019-ncov/if-you-are-sick/care-for-someone.html|url-status=live|archive-url=|archive-date=|access-date=2020-07-03|website=U.S. Centers for Disease Control and Prevention (CDC) }}</ref> When not wearing a mask, the CDC recommends covering the mouth and nose with a tissue when coughing or sneezing and recommends using the inside of the elbow if no tissue is available.<ref name="CDC-Prevention & Treatment" /> Proper hand hygiene after any cough or sneeze is encouraged.<ref name="CDC-Prevention & Treatment" />

[[Medicine:Social distancing|Social distancing]] strategies aim to reduce contact of infected persons with large groups by closing schools and workplaces, restricting travel, and cancelling large public gatherings.<ref name="JHUSocialDistancing">{{cite web | first = Lisa Lockerd | last = Maragakis | name-list-format = vanc | title = Coronavirus, Social Distancing and Self Quarantine | url = https://www.hopkinsmedicine.org/health/conditions-and-diseases/coronavirus/coronavirus-social-distancing-and-self-quarantine | website = www.hopkinsmedicine.org | publisher = Johns Hopkins University | access-date = 18 March 2020 | archive-url = https://web.archive.org/web/20200318012357/https://www.hopkinsmedicine.org/health/conditions-and-diseases/coronavirus/coronavirus-social-distancing-and-self-quarantine | archive-date = 18 March 2020 | url-status = live }}</ref> Distancing guidelines also include that people stay at least {{Convert|6|ft||abbr=}} apart.<ref>{{cite news|last=Parker-Pope|first=Tara|  name-list-format = vanc |url=https://www.nytimes.com/2020/03/19/well/live/coronavirus-quarantine-social-distancing.html|title=Deciding How Much Distance You Should Keep|date=19 March 2020|work={{wipe|The New York Times}}|access-date=20 March 2020|issn=0362-4331|archive-url=https://web.archive.org/web/20200320003705/https://www.nytimes.com/2020/03/19/well/live/coronavirus-quarantine-social-distancing.html|archive-date=20 March 2020|url-status=live }}</ref>  After the implementation of [[Medicine:Social distancing|social distancing]] and [[Social:Shelter in place|stay-at-home]] orders, many regions have been able to sustain an effective transmission rate ("R<sub>t</sub>") of less than one, meaning the disease is in remission in those areas.<ref>{{cite web |last1=Systrom |first1=Kevin |last2=Krieger |first2=Mike |last3=O'Rourke |first3=Ryan |last4=Stein |first4=Robby |first5=Frank |last5=Dellaert |first6=Adam |last6=Lerer | name-list-format = vanc |title=R<sub>t</sub> Covid-19 |url=https://rt.live/ |website=rt.live |access-date=19 April 2020 |date=11 April 2020}} Based on {{cite journal | vauthors = Bettencourt LM, Ribeiro RM | title = Real time bayesian estimation of the epidemic potential of emerging infectious diseases | journal = PLOS ONE | volume = 3 | issue = 5 | pages = e2185 | date = May 2008 | pmid = 18478118 | pmc = 2366072 | doi = 10.1371/journal.pone.0002185 | bibcode = 2008PLoSO...3.2185B }}</ref>

The CDC also recommends that individuals wash hands often with soap and water for at least 20 seconds, especially after going to the toilet or when hands are visibly dirty, before eating and after blowing one's nose, coughing or sneezing. The CDC further recommends using an alcohol-based hand sanitiser with at least 60% alcohol, but only when soap and water are not readily available.<ref name="CDC-Prevention & Treatment" /> For areas where commercial hand sanitisers are not readily available, the WHO provides two formulations for local production. In these formulations, the antimicrobial activity arises from [[Chemistry:Ethanol|ethanol]] or isopropanol. [[Chemistry:Hydrogen peroxide|Hydrogen peroxide]] is used to help eliminate bacterial spores in the alcohol; it is "not an active substance for hand antisepsis". [[Chemistry:Glycerol|Glycerol]] is added as a [[Chemistry:Humectant|humectant]].<ref>{{cite book | chapter-url = https://www.ncbi.nlm.nih.gov/books/NBK144054/ | chapter = WHO-recommended handrub formulations | title = WHO Guidelines on Hand Hygiene in Health Care: First Global Patient Safety Challenge Clean Care Is Safer Care. |date=19 March 2009 |publisher=World Health Organization|access-date=19 March 2020 }}</ref>

Those diagnosed with COVID‑19 or who believe they may be infected are advised by the CDC to stay home except to get medical care, call ahead before visiting a healthcare provider, wear a face mask before entering the healthcare provider's office and when in any room or vehicle with another person, cover coughs and sneezes with a tissue, regularly wash hands with soap and water and avoid sharing personal household items.<ref name="CDC2020IfSick" /><ref>{{cite web | url = https://www.cdc.gov/coronavirus/2019-ncov/about/prevention.html | title = Coronavirus Disease 2019 (COVID-19)—Prevention & Treatment | date = 10 March 2020 | work = U.S. Centers for Disease Control and Prevention (CDC) | access-date = 11 March 2020 | archive-url = https://web.archive.org/web/20200311163637/https://www.cdc.gov/coronavirus/2019-ncov/about/prevention.html | archive-date = 11 March 2020 | url-status = live }}</ref>

Sanitizing of frequently touched surfaces is also recommended or required by regulation for businesses and public facilities; the United States Environmental Protection Agency maintains a list of products expected to be effective.<ref>{{Cite web|url=https://www.epa.gov/pesticide-registration/list-n-disinfectants-use-against-sars-cov-2-covid-19|title=List N: Disinfectants for Use Against SARS-CoV-2 (COVID-19)|first=OCSPP|last=US EPA|date=13 March 2020|website=US EPA}}</ref>

On 7 July 2020, the WHO said in a press conference that it will issue new guidelines about airborne transmission in settings with close contact and poor ventilation.<ref>{{Cite journal|last=Lewis|first=Dyani|date=2020-07-08|title=Mounting evidence suggests coronavirus is airborne — but health advice has not caught up|url=https://www.nature.com/articles/d41586-020-02058-1|journal=Nature|language=en|doi=10.1038/d41586-020-02058-1}}</ref>

For health care professionals who may come into contact with COVID-19 positive bodily fluids, using personal protective coverings on exposed body parts improves protection from the virus.<ref name=":7">{{Cite journal|last=Verbeek|first=Jos H.|last2=Rajamaki|first2=Blair|last3=Ijaz|first3=Sharea|last4=Sauni|first4=Riitta|last5=Toomey|first5=Elaine|last6=Blackwood|first6=Bronagh|last7=Tikka|first7=Christina|last8=Ruotsalainen|first8=Jani H.|last9=Kilinc Balci|first9=F. Selcen|date=May 15, 2020|title=Personal protective equipment for preventing highly infectious diseases due to exposure to contaminated body fluids in healthcare staff|url=https://www.ncbi.nlm.nih.gov/pubmed/32412096|journal=The Cochrane Database of Systematic Reviews|volume=5|pages=CD011621|doi=10.1002/14651858.CD011621.pub5|issn=1469-493X|pmid=32412096}}</ref> Breathable personal protective equipment improves user-satisfaction and may offer a similar level of protection from the virus.<ref name=":7" /> In addition, adding tabs and other modifications to the protective equipment may reduce the risk of contamination during donning and doffing (putting on and taking off the equipment).<ref name=":7" /> Implementing an evidence-based donning and doffing protocol such as a one-step glove and gown removal technique, giving oral instructions while donning and doffing, double gloving, and the use of glove disinfection may also improve protection for health care professionals.<ref name=":7" />

==Management==


People are managed with supportive care, which may include [[Medicine:Fluid replacement|fluid therapy]], oxygen support, and supporting other affected vital organs.<ref name="NatureDale Fisher & David Heymann">{{cite journal | vauthors = Fisher D, Heymann D | title = Q&A: The novel coronavirus outbreak causing COVID-19 | journal = BMC Medicine | volume = 18 | issue = 1 | pages = 57 | date = February 2020 | pmid = 32106852 | pmc = 7047369 | doi = 10.1186/s12916-020-01533-w | doi-access = free }}</ref><ref name="KuiFang2020">{{cite journal | vauthors = Liu K, Fang YY, Deng Y, Liu W, Wang MF, Ma JP, Xiao W, Wang YN, Zhong MH, Li CH, Li GC, Liu HG | display-authors = 6 | title = Clinical characteristics of novel coronavirus cases in tertiary hospitals in Hubei Province | journal = Chinese Medical Journal | volume = 133 | issue = 9 | pages = 1025–1031 | date = May 2020 | pmid = 32044814 | pmc = 7147277 | doi = 10.1097/CM9.0000000000000744 | doi-access = free }}</ref><ref name="Wang Du Zhu Cao 2020 p.">{{cite journal | vauthors = Wang T, Du Z, Zhu F, Cao Z, An Y, Gao Y, Jiang B | title = Comorbidities and multi-organ injuries in the treatment of COVID-19 | journal = Lancet | volume = 395 | issue = 10228 | pages = e52 | date = March 2020 | pmid = 32171074 | doi = 10.1016/s0140-6736(20)30558-4 | pmc = 7270177 | doi-access = free }}</ref> The CDC recommends those who suspect they carry the virus wear a simple face mask.<ref name=CDC2020IfSick/> [[Engineering:Extracorporeal membrane oxygenation|Extracorporeal membrane oxygenation]] (ECMO) has been used to address the issue of respiratory failure, but its benefits are still under consideration.{{citation needed|date=June 2020}}<ref name="Henry 2020 p.">{{cite journal | vauthors = Henry BM | title = COVID-19, ECMO, and lymphopenia: a word of caution | journal = The Lancet. Respiratory Medicine | volume = 8 | issue = 4 | pages = e24 | date = April 2020 | pmid = 32178774 | pmc = 7118650 | doi = 10.1016/s2213-2600(20)30119-3 }}</ref> Personal hygiene and a healthy lifestyle and diet have been recommended to improve immunity.<ref>{{cite journal | vauthors = Wang L, Wang Y, Ye D, Liu Q | title = Review of the 2019 novel coronavirus (SARS-CoV-2) based on current evidence | journal = International Journal of Antimicrobial Agents | pages = 105948 | date = March 2020 | volume = 55 | issue = 6 | pmid = 32201353 | pmc = 7156162 | doi = 10.1016/j.ijantimicag.2020.105948 | url = https://www.sciencedirect.com/science/article/pii/S0924857920300984 | access-date = 27 March 2020 | url-status = live | archive-url = https://web.archive.org/web/20200327232545/https://www.sciencedirect.com/science/article/pii/S0924857920300984 | archive-date = 27 March 2020 }}</ref> Supportive treatments may be useful in those with mild symptoms at the early stage of infection.<ref>{{cite journal | vauthors = Wang Y, Wang Y, Chen Y, Qin Q | title = Unique epidemiological and clinical features of the emerging 2019 novel coronavirus pneumonia (COVID-19) implicate special control measures | journal = Journal of Medical Virology | volume = n/a | issue = n/a | pages = 568–576 | date = March 2020 | pmid = 32134116 | doi = 10.1002/jmv.25748 | pmc = 7228347 | doi-access = free }}</ref>

The WHO, the Chinese National Health Commission, and the United States' [[Organization:National Institutes of Health|National Institutes of Health]] have published recommendations for taking care of people who are hospitalised with COVID‑19.<ref name="NIHGuidelines2020">{{cite web |title=COVID-19 Treatment Guidelines |url=https://covid19treatmentguidelines.nih.gov/introduction/ |website=www.nih.gov |publisher=National Institutes of Health |access-date=21 April 2020}}</ref><ref name="Cheng2020">{{cite journal | vauthors = Cheng ZJ, Shan J | title = 2019 Novel coronavirus: where we are and what we know | journal = Infection | volume = 48 | issue = 2 | pages = 155–163 | date = April 2020 | pmid = 32072569 | pmc = 7095345 | doi = 10.1007/s15010-020-01401-y | doi-access = free }}</ref><ref>{{cite web|url=https://www.who.int/publications-detail/clinical-management-of-severe-acute-respiratory-infection-when-novel-coronavirus-(ncov)-infection-is-suspected|title=Clinical management of severe acute respiratory infection when novel coronavirus (nCoV) infection is suspected|website=[[Organization:World Health Organization|World Health Organization]] (WHO)|access-date=13 February 2020|archive-url=https://web.archive.org/web/20200131032122/https://www.who.int/publications-detail/clinical-management-of-severe-acute-respiratory-infection-when-novel-coronavirus-(ncov)-infection-is-suspected|archive-date=31 January 2020|url-status=live }}</ref> Intensivists and pulmonologists in the US have compiled treatment recommendations from various agencies into a free resource, the IBCC.<ref name="IBCC">{{cite book |last=Farkas |first=Josh | name-list-format = vanc |date=March 2020 |title=COVID-19—The Internet Book of Critical Care |url=https://emcrit.org/ibcc/covid19/ |url-status=live |format=digital |type=Reference manual |location=USA |publisher=EMCrit |archive-url=https://web.archive.org/web/20200311195758/https://emcrit.org/ibcc/covid19/ |archive-date=11 March 2020 |access-date=13 March 2020}}</ref><ref name="UPenn-IBCC">{{cite web |url=https://guides.library.upenn.edu/covid-19 |title=COVID19—Resources for Health Care Professionals |publisher=Penn Libraries |date=11 March 2020 |access-date=13 March 2020 |archive-url=https://web.archive.org/web/20200314035631/https://guides.library.upenn.edu/covid-19 |archive-date=14 March 2020 |url-status=live }}</ref>

==Prognosis==
{{Multiple image
| align = right
| direction = vertical
| total_width = 400
| caption_align = center
| image1 = Severity-of-coronavirus-cases-in-China-1.svg
| alt1 = The severity of diagnosed cases in China
| caption1 = The severity of diagnosed COVID-19 cases in China<ref>{{cite journal |last1=Roser |first1=Max |last2=Ritchie |first2=Hannah |last3=Ortiz-Ospina |first3=Esteban |name-list-format=vanc |title=Coronavirus Disease (COVID-19) |url=https://ourworldindata.org/coronavirus |journal=Our World in Data |access-date=12 March 2020 |date=4 March 2020 |archive-url=https://web.archive.org/web/20200319171947/https://ourworldindata.org/coronavirus |archive-date=19 March 2020 |url-status=live }}</ref>
| image2 = COVID-CFR-by-age-CN-KR-ES-IT-latest-nolegend.svg
| alt2 = Case fatality rates for COVID-19 by age by country.
| caption2 = <div style="text-align: left;">Case fatality rates by age group: {{legend|#d62728|China, as of 11 February 2020<ref name="Epidemiology2020Feb17" />}} {{legend|#2ca02c|South Korea, as of 17 July 2020<ref name="KCDCReport-20200605">{{cite report|url=https://www.cdc.go.kr/board/board.es?mid=a20501000000&bid=0015&list_no=367829&act=view|title=코로나바이러스감염증-19 국내 발생 현황(7월 17일, 정례브리핑) |language=ko|date=2020-07-17|publisher=[[Organization:Korea Centers for Disease Control and Prevention|Korea Centers for Disease Control and Prevention]]|access-date=2020-07-17|url-status=live}}</ref>}} {{legend|#ff7f0e|Spain, as of 18 May 2020<ref name="MSCBSReport">{{cite report|url=https://www.mscbs.gob.es/profesionales/saludPublica/ccayes/alertasActual/nCov-China/documentos/Actualizacion_109_COVID-19.pdf|title=Actualización nº 109. Enfermedad por el coronavirus (COVID-19)|date=18 May 2020|publisher=Ministerio de Sanidad, Consumo y Bienestar Social|language=Spanish|access-date=20 May 2020|url-status=live}}</ref>}} {{legend|#1f77b4|Italy, as of 3 June 2020<ref>{{cite web|url=https://www.epicentro.iss.it/coronavirus/bollettino/Bollettino-sorveglianza-integrata-COVID-19_3-giugno-2020.pdf|title=Epidemia COVID-19 – Bollettino sorveglianza integrata COVID-19|publisher=[[Organization:Istituto Superiore di Sanità|Istituto Superiore di Sanità]]|access-date=10 June 2020|language=it|date=5 June 2020}}</ref>}}</div>
| image3 = Comorbidity and severity in covid-19 data from China CDC Weekly 2020, 2(8), pp. 113-122 (cropped).png
| alt3 = Case fatality rate depending on other health problems
| caption3 = Case fatality rate in China depending on other health problems. Data through 11 February 2020.<ref name="Epidemiology2020Feb17" />
| image4 = Covid-19-total-confirmed-cases-vs-total-confirmed-deaths.svg
| alt4 = Case fatality rate by country and number of cases
| caption4 = The number of deaths vs total cases by country and approximate case fatality rate<ref>{{cite journal |last1=Roser |first1=Max |last2=Ritchie |first2=Hannah |last3=Ortiz-Ospina |first3=Esteban |name-list-format=vanc |title=Coronavirus Disease (COVID-19) |url=https://ourworldindata.org/coronavirus |journal=Our World in Data |access-date=6 April 2020 |date=6 April 2020}}</ref>
}}

The severity of COVID‑19 varies. The disease may take a mild course with few or no symptoms, resembling other common upper respiratory diseases such as the [[Medicine:Common cold|common cold]]. Mild cases typically recover within two weeks, while those with severe or critical diseases may take three to six weeks to recover. Among those who have died, the time from symptom onset to death has ranged from two to eight weeks.<ref name="WHOReport24Feb2020">{{cite report|url=https://www.who.int/docs/default-source/coronaviruse/who-china-joint-mission-on-covid-19-final-report.pdf|title=Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19)|date=16–24 February 2020|publisher=[[Organization:World Health Organization|World Health Organization]] (WHO)|access-date=21 March 2020|archive-url=https://web.archive.org/web/20200229221222/https://www.who.int/docs/default-source/coronaviruse/who-china-joint-mission-on-covid-19-final-report.pdf|archive-date=29 February 2020|url-status=live}}</ref>

Children make up a small proportion of reported cases, with about 1% of cases being under 10 years and 4% aged 10–19 years.<ref name="ECDCQA" /> They are likely to have milder symptoms and a lower chance of severe disease than adults. In those younger than 50 years the risk of death is less than 0.5%, while in those older than 70 it is more than 8%.<ref name="JAMAPedsCOVID19">{{cite journal | vauthors = Castagnoli R, Votto M, Licari A, Brambilla I, Bruno R, Perlini S, Rovida F, Baldanti F, Marseglia GL | display-authors = 6 | title = Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection in Children and Adolescents: A Systematic Review | journal = JAMA Pediatrics | date = April 2020 | pmid = 32320004 | doi = 10.1001/jamapediatrics.2020.1467 | url = https://jamanetwork.com/journals/jamapediatrics/fullarticle/2765169 | doi-access = free }}</ref><ref name="Lu Zhang Du Zhang p.">{{cite journal | vauthors = Lu X, Zhang L, Du H, Zhang J, Li YY, Qu J, Zhang W, Wang Y, Bao S, Li Y, Wu C, Liu H, Liu D, Shao J, Peng X, Yang Y, Liu Z, Xiang Y, Zhang F, Silva RM, Pinkerton KE, Shen K, Xiao H, Xu S, Wong GW | display-authors = 6 | title = SARS-CoV-2 Infection in Children | journal = New England Journal of Medicine | volume = 382 | issue = 17 | pages = 1663–1665 | date = April 2020 | pmid = 32187458 | pmc = 7121177 | doi = 10.1056/nejmc2005073 | publisher = Massachusetts Medical Society }}</ref><ref name="pediatrics_tong">{{cite journal | vauthors = Dong Y, Mo X, Hu Y, Qi X, Jiang F, Jiang Z, Tong S | title = Epidemiology of COVID-19 Among Children in China | journal = Pediatrics | pages = e20200702 | date = March 2020 | volume = 145 | issue = 6 | pmid = 32179660 | doi = 10.1542/peds.2020-0702 | url = https://pediatrics.aappublications.org/content/pediatrics/early/2020/03/16/peds.2020-0702.full.pdf | access-date = 16 March 2020 | url-status = live | archive-url = https://web.archive.org/web/20200317223427/https://pediatrics.aappublications.org/content/pediatrics/early/2020/03/16/peds.2020-0702.full.pdf | archive-date = 17 March 2020 }}</ref> Pregnant women may be at higher risk of severe COVID‑19 infection based on data from other similar viruses, like [[Unsolved:Severe acute respiratory syndrome|severe acute respiratory syndrome]] (SARS) and [[Medicine:Middle East respiratory syndrome|Middle East respiratory syndrome]] (MERS), but data for COVID‑19 is lacking.<ref>{{cite journal | vauthors = Fang L, Karakiulakis G, Roth M | title = Are patients with hypertension and diabetes mellitus at increased risk for COVID-19 infection? | journal = The Lancet. Respiratory Medicine | volume = 8 | issue = 4 | pages = e21 | date = April 2020 | pmid = 32171062 | pmc = 7118626 | doi = 10.1016/S0140-6736(20)30311-1 }}</ref><ref name="CDC 2020children">{{cite web|url=https://www.cdc.gov/coronavirus/2019-ncov/specific-groups/children-faq.html|title=Coronavirus Disease 2019 (COVID-19)|author=|date=11 February 2020|website=U.S. Centers for Disease Control and Prevention (CDC) |access-date=2 March 2020|name-list-format=vanc|archive-url=https://web.archive.org/web/20200302064104/https://www.cdc.gov/coronavirus/2019-ncov/specific-groups/children-faq.html|archive-date=2 March 2020|url-status=live}}</ref>  According to scientific reviews smokers are more likely to require intensive care or die compared to non-smokers,<ref>{{cite journal | vauthors = Vardavas CI, Nikitara K | title = COVID-19 and smoking: A systematic review of the evidence | journal = Tobacco Induced Diseases | volume = 18 | issue = March | pages = 20 | date = 20 March 2020 | pmid = 32206052 | pmc = 7083240 | doi = 10.18332/tid/119324 }}</ref><ref name="engin-review">{{cite journal |last1=Engin |first1=Ayse Basak |last2=Engin |first2=Evren Doruk |last3=Engin |first3=Atilla |title=Two important controversial risk factors in SARS-CoV-2 infection: Obesity and smoking |journal=Environmental Toxicology and Pharmacology |date=1 August 2020 |volume=78 |pages=103411 |doi=10.1016/j.etap.2020.103411 |pmid=32422280 |pmc=7227557 |url=https://www.sciencedirect.com/science/article/pii/S1382668920300879 |accessdate=31 May 2020 |issn=1382-6689}}</ref> [[Earth:Air pollution|air pollution]] is similarly associated with risk factors,<ref name="engin-review"/> and obesity contributes to an increased health risk of COVID-19.<ref name="engin-review"/><ref>{{cite journal |last1=Tamara |first1=Alice |last2=Tahapary |first2=Dicky L. |title=Obesity as a predictor for a poor prognosis of COVID-19: A systematic review |journal=Diabetes & Metabolic Syndrome: Clinical Research & Reviews |date=1 July 2020 |volume=14 |issue=4 |pages=655–659 |doi=10.1016/j.dsx.2020.05.020 |pmid=32438328 |pmc=7217103 |url=https://www.sciencedirect.com/science/article/pii/S1871402120301399 |accessdate=31 May 2020 |issn=1871-4021|doi-access=free }}</ref><ref>{{cite journal |title=Obesity ‑ a risk factor for increased COVID‑19 prevalence, severity and lethality (Review) |journal=Molecular Medicine Reports |url=https://www.researchgate.net/publication/341162753 |accessdate=31 May 2020}}</ref>

A European multinational study of hospitalized children published in ''The Lancet'' on June 25, 2020 found that about 8% of children admitted to a hospital needed intensive care.  4 out of 582 children (0.7%) died, although the actual mortality rate could be “substantially lower” since milder cases that did not seek medical help were not included in the study.<ref>[https://www.contagionlive.com/news/study-majority-of-children-with-covid19-have-mild-disease-mortality-is-rare John Parkinson, “Study: Majority of Children with COVID-19 Have Mild Disease, Mortality is Rare”, Contagion Live, 25 June 2020.]</ref>  


===Comorbidities===

Most of those who die of COVID‑19 have pre-existing (underlying) conditions, including [[Medicine:Hypertension|hypertension]], [[Medicine:Diabetes mellitus|diabetes mellitus]], and [[Medicine:Cardiovascular disease|cardiovascular disease]].<ref name=":8">{{cite web |url=https://www.who.int/dg/speeches/detail/who-director-general-s-statement-on-the-advice-of-the-ihr-emergency-committee-on-novel-coronavirus |title=WHO Director-General's statement on the advice of the IHR Emergency Committee on Novel Coronavirus |website=[[Organization:World Health Organization|World Health Organization]] (WHO) }}</ref> The [[Organization:Istituto Superiore di Sanità|Istituto Superiore di Sanità]] reported that out of 8.8% of deaths where [[Medicine:Medical record|medical charts]] were available, 97% of people had at least one [[Medicine:Comorbidity|comorbidity]] with the average person having 2.7 diseases.<ref name="ISSCharacteristics">{{cite report|vauthors=Palmieri L, Andrianou X, Barbariol P, Bella A, Bellino S, Benelli E, Bertinato L, Boros S, Brambilla G, Calcagnini G, Canevelli M, Castrucci MR, Censi F, Ciervo A, Colaizzo E, D'Ancona F, Del Manso M, Donfrancesco C, Fabiani M, Filia A, Floridia M, Giuliano M, Grisetti T, Langer M, Lega I, Lo Noce C, Maiozzi P, Malchiodi Albedi F, Manno V, Martini M, Mateo Urdiales A, Mattei E, Meduri C, Meli P, Minelli G, Nebuloni M, Nisticò L, Nonis M, Onder G, Palmisano L, Petrosillo N, Pezzotti P, Pricci F, Punzo O, Puro V, Raparelli V, Rezza G, Riccardo F, Rota MC, Salerno P, Serra D, Siddu A, Stefanelli P, Tamburo De Bella M, Tiple D, Unim B, Vaianella L, Vanacore N, Vichi M, Villani ER, Brusaferro S|display-authors= 6|title=Characteristics of COVID-19 patients dying in Italy Report based on available data on April 2nd, 2020|url=https://www.epicentro.iss.it/en/coronavirus/bollettino/Report-COVID-2019_2_april_2020.pdf|date=3 April 2020|publisher=[[Organization:Istituto Superiore di Sanità|Istituto Superiore di Sanità]]|access-date=3 April 2020|url-status=live}}</ref> According to the same report, the median time between the onset of symptoms and death was ten days, with five being spent hospitalised. However, people transferred to an ICU had a median time of seven days between hospitalisation and death.<ref name="ISSCharacteristics" /> In a study of early cases, the median time from exhibiting initial symptoms to death was 14 days, with a full range of six to 41 days.<ref>{{cite journal | vauthors = Wang W, Tang J, Wei F | title = Updated understanding of the outbreak of 2019 novel coronavirus (2019-nCoV) in Wuhan, China | journal = Journal of Medical Virology | volume = 92 | issue = 4 | pages = 441–447 | date = April 2020 | pmid = 31994742 | pmc = 7167192 | doi = 10.1002/jmv.25689 | doi-access = free }}</ref> In a study by the National Health Commission (NHC) of China, men had a death rate of 2.8% while women had a death rate of 1.7%.<ref name="WM2020Feb26">{{cite web |title=Coronavirus Age, Sex, Demographics (COVID-19) |url=https://www.worldometers.info/coronavirus/coronavirus-age-sex-demographics/ |website=www.worldometers.info |access-date=26 February 2020 |archive-url=https://web.archive.org/web/20200227112932/https://www.worldometers.info/coronavirus/coronavirus-age-sex-demographics/ |archive-date=27 February 2020 |url-status=live | name-list-format = vanc}}</ref> In 11.8% of the deaths reported by the National Health Commission of China, heart damage was noted by elevated levels of troponin or cardiac arrest.<ref name="Zheng Ma Zhang Xie p.">{{cite journal | vauthors = Zheng YY, Ma YT, Zhang JY, Xie X | title = COVID-19 and the cardiovascular system | journal = Nature Reviews. Cardiology | volume = 17 | issue = 5 | pages = 259–260 | date = May 2020 | pmid = 32139904 | pmc = 7095524 | doi = 10.1038/s41569-020-0360-5 | doi-access = free }}</ref> According to March data from the United States, 89% of those hospitalised had preexisting conditions.<ref>{{cite journal | vauthors = Garg S, Kim L, Whitaker M, O'Halloran A, Cummings C, Holstein R, Prill M, Chai SJ, Kirley PD, Alden NB, Kawasaki B, Yousey-Hindes K, Niccolai L, Anderson EJ, Openo KP, Weigel A, Monroe ML, Ryan P, Henderson J, Kim S, Como-Sabetti K, Lynfield R, Sosin D, Torres S, Muse A, Bennett NM, Billing L, Sutton M, West N, Schaffner W, Talbot HK, Aquino C, George A, Budd A, Brammer L, Langley G, Hall AJ, Fry A | display-authors = 6 | title = Hospitalization Rates and Characteristics of Patients Hospitalized with Laboratory-Confirmed Coronavirus Disease 2019—COVID-NET, 14 States, 1–30 March 2020 | journal = MMWR. Morbidity and Mortality Weekly Report | volume = 69 | issue = 15 | pages = 458–464 | date = April 2020 | pmid = 32298251 | doi = 10.15585/mmwr.mm6915e3 | url = https://www.cdc.gov/mmwr/volumes/69/wr/mm6915e3.htm | doi-access = free }}</ref>

Most critical respiratory [[Medicine:Comorbidity|comorbidities]] according to the CDC, are: moderate or severe [[Medicine:Asthma|Asthma]], pre-existing [[Medicine:Chronic obstructive pulmonary disease|COPD]], [[Medicine:Pulmonary fibrosis|pulmonary fibrosis]], [[Medicine:Cystic fibrosis|cystic fibrosis]].<ref>{{Cite web|last=CDC|date=2020-02-11|title=Coronavirus Disease 2019 (COVID-19)|url=https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/groups-at-higher-risk.html|access-date=2020-06-19|website=Centers for Disease Control and Prevention|language=en-us}}</ref> Current evidence stemming from meta - analysis of several smaller research papers, also suggest that [[Medicine:Smoking|smoking]] can be assosiated with worse patient outcomes <ref>{{Cite journal|last=Zhao|first=Qianwen|last2=Meng|first2=Meng|last3=Kumar|first3=Rahul|last4=Wu|first4=Yinlian|last5=Huang|first5=Jiaofeng|last6=Lian|first6=Ningfang|last7=Deng|first7=Yunlei|last8=Lin|first8=Su|date=2020-05-17|title=The impact of COPD and smoking history on the severity of COVID‐19: A systemic review and meta‐analysis|url=http://dx.doi.org/10.1002/jmv.25889|journal=Journal of Medical Virology|doi=10.1002/jmv.25889|issn=0146-6615}}</ref><ref>{{Cite web|title=Smoking and COVID-19|url=https://www.who.int/news-room/commentaries/detail/smoking-and-covid-19|access-date=2020-06-19|website=www.who.int|language=en}}</ref> When someone with existing respiratory problems is infected with COVID-19, they might be at greater risk for severe symptoms.<ref>{{cite web|title=Coronavirus Disease 2019 (COVID-19)|url=https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/groups-at-higher-risk.html|date=11 February 2020|website=Centers for Disease Control and Prevention (CDC) |access-date=4 May 2020}}</ref> COVID-19 also poses a greater risk to people who [[Medicine:Opioid use disorder|misuse opioids]] and methamphetamines, insofar as their drug use may have caused lung damage.<ref>{{cite web|title=People who use drugs are more vulnerable to coronavirus. Here's what clinics are doing to help.|url=https://www.theadvocate.com/baton_rouge/news/coronavirus/article_f80cf77e-84fa-11ea-88d5-2b37dc9dd966.html|last=DeRobertis|first=Jacqueline| name-list-format = vanc |date=3 May 2020|website=The Advocate (Louisiana)|url-status=live|archive-url=|archive-date=|access-date=4 May 2020}}</ref>

===Complications and long-term effects===

Complications may include [[Medicine:Pneumonia|pneumonia]], [[Medicine:Acute respiratory distress syndrome|acute respiratory distress syndrome]] (ARDS), [[Medicine:Multiple organ dysfunction syndrome|multi-organ failure]], [[Medicine:Septic shock|septic shock]], and death.<ref name="Hui14Jan2020"/><ref name="auto"/><ref name="StatPearls">{{cite book|title=StatPearls|vauthors=Cascella M, Rajnik M, Cuomo A, Dulebohn SC, Di Napoli R|date=2020|publisher=StatPearls Publishing|location=Treasure Island (FL)|chapter=Features, Evaluation and Treatment Coronavirus (COVID-19)|pmid=32150360|access-date=18 March 2020|chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK554776/}}</ref><ref name="Heymann Shindo 2020 pp. 542–545222">{{cite journal | vauthors = Heymann DL, Shindo N | title = COVID-19: what is next for public health? | journal = Lancet | volume = 395 | issue = 10224 | pages = 542–545 | date = February 2020 | pmid = 32061313 | pmc = 7138015 | doi = 10.1016/s0140-6736(20)30374-3 | collaboration = WHO Scientific and Technical Advisory Group for Infectious Hazards }}</ref> Cardiovascular complications may include [[Medicine:Heart failure|heart failure]], [[Medicine:Arrhythmia|arrhythmia]]s, [[Medicine:Myocarditis|heart inflammation]], and blood clots.<ref name=":03">{{cite journal | vauthors = Long B, Brady WJ, Koyfman A, Gottlieb M | title = Cardiovascular complications in COVID-19 | journal = The American Journal of Emergency Medicine | date = April 2020 | volume = 38 | issue = 7 | pages = 1504–1507 | pmid = 32317203 | pmc = 7165109 | doi = 10.1016/j.ajem.2020.04.048}}</ref>

Approximately 20–30% of people who present with COVID‑19 have [[Medicine:Elevated transaminases|elevated liver enzymes]] reflecting liver injury.<ref>{{cite journal | vauthors = Xu L, Liu J, Lu M, Yang D, Zheng X | title = Liver injury during highly pathogenic human coronavirus infections | journal = Liver International | volume = 40 | issue = 5 | pages = 998–1004 | date = May 2020 | pmid = 32170806 | doi = 10.1111/liv.14435 | pmc = 7228361 | doi-access = free }}</ref><ref name="Sanders20202">{{cite journal | vauthors = Sanders JM, Monogue ML, Jodlowski TZ, Cutrell JB | title = Pharmacologic Treatments for Coronavirus Disease 2019 (COVID-19): A Review | journal = JAMA | date = April 2020 | pmid = 32282022 | doi = 10.1001/jama.2020.6019 | doi-access = free }}</ref>

Neurologic manifestations include seizure, [[Medicine:Stroke|stroke]], [[Medicine:Encephalitis|encephalitis]], and [[Medicine:Guillain–Barré syndrome|Guillain–Barré syndrome]] (which includes loss of motor functions).<ref name=":13">{{cite journal | vauthors = Carod-Artal FJ | title = Neurological complications of coronavirus and COVID-19 | journal = Revista de Neurología | volume = 70 | issue = 9 | pages = 311–322 | date = May 2020 | pmid = 32329044 | doi = 10.33588/rn.7009.2020179 }}</ref> Following the infection, children may develop [[Medicine:Paediatric multisystem inflammatory syndrome|paediatric multisystem inflammatory syndrome]], which has symptoms similar to [[Medicine:Kawasaki disease|Kawasaki disease]], which can be fatal.<ref>{{cite web |title=Multisystem inflammatory syndrome in children and adolescents temporally related to COVID-19 |url=https://www.who.int/news-room/commentaries/detail/multisystem-inflammatory-syndrome-in-children-and-adolescents-with-covid-19 |website=[[Organization:World Health Organization|World Health Organization]] (WHO) |accessdate=20 May 2020 }}</ref><ref>{{cite report |title=HAN Archive—00432 |url=https://emergency.cdc.gov/han/2020/han00432.asp |website=U.S. Centers for Disease Control and Prevention (CDC) |accessdate=20 May 2020 |date=15 May 2020}}</ref>

Concerns have been raised about long-term [[Medicine:Sequela|sequela]]e of the disease. The Hong Kong Hospital Authority found a drop of 20% to 30% in lung capacity in some people who recovered from the disease, and lung scans suggested organ damage.<ref>{{cite web |last1=Cheung |first1=Elizabeth |name-list-format=vanc |title=Some recovered Covid-19 patients may have lung damage, doctors say |url=https://www.scmp.com/news/hong-kong/health-environment/article/3074988/coronavirus-some-recovered-patients-may-have |website=South China Morning Post |date=13 March 2020 |access-date=15 March 2020 |archive-url=https://web.archive.org/web/20200315172445/https://www.scmp.com/news/hong-kong/health-environment/article/3074988/coronavirus-some-recovered-patients-may-have |archive-date=15 March 2020 |url-status=live}}</ref> This may also lead to [[Medicine:Post-intensive care syndrome|post-intensive care syndrome]] following recovery.<ref>{{cite journal |last=Servick |first=Kelly |name-list-format=vanc |date=8 April 2020 |title=For survivors of severe COVID-19, beating the virus is just the beginning |url=https://www.sciencemag.org/news/2020/04/survivors-severe-covid-19-beating-virus-just-beginning |journal=Science |doi=10.1126/science.abc1486 |doi-access=free |issn=0036-8075}}</ref>

===Immunity===

It is unknown (as of April 2020) if past infection provides effective and long-term [[Medicine:Immunity (medical)|immunity]] in people who recover from the disease.<ref>{{cite web|url=https://www.immunology.org/news/bsi-open-letter-government-sars-cov-2-outbreak-response|title=BSI open letter to Government on SARS-CoV-2 outbreak response | publisher= British Society for Immunology|website= immunology.org|access-date=15 March 2020|archive-url= https://web.archive.org/web/20200314221816/https://www.immunology.org/news/bsi-open-letter-government-sars-cov-2-outbreak-response|archive-date=14 March 2020 |url-status=live}}</ref><ref name="Immunity Passports">{{cite news |last1=Schraer |first1=Rachel |title=Coronavirus: Immunity passports 'could increase virus spread' |url=https://www.bbc.com/news/world-52425825 |access-date=26 April 2020 |date=25 April 2020}}</ref> Some of the infected have been reported to develop [[Biology:Antibody|protective antibodies]], so [[Biology:Adaptive immune system|acquired immunity]] is presumed likely, based on the behaviour of other coronaviruses.<ref>{{cite news| url= https://www.independent.co.uk/life-style/health-and-families/coronavirus-immunity-reinfection-get-covid-19-twice-sick-spread-relapse-a9400691.html |title= Can you get coronavirus twice or does it cause immunity?|date=13 March 2020|website=The Independent|access-date=15 March 2020|archive-url= https://web.archive.org/web/20200314211439/https://www.independent.co.uk/life-style/health-and-families/coronavirus-immunity-reinfection-get-covid-19-twice-sick-spread-relapse-a9400691.html|archive-date=14 March 2020|url-status=live}}</ref> Cases in which recovery from COVID‑19 was followed by positive tests for coronavirus at a later date have been reported.<ref name="SLT-202004112">{{cite news |last=Politi |first=Daniel | name-list-format = vanc |title=WHO Investigating Reports of Coronavirus Patients Testing Positive Again After Recovery |url=https://slate.com/news-and-politics/2020/04/who-reports-coronavirus-testing-positive-recovery.html |date=11 April 2020 |work=Slate |access-date=11 April 2020 }}</ref><ref>{{cite web|url=https://www.latimes.com/world-nation/story/2020-03-13/china-japan-korea-coronavirus-reinfection-test-positive|title=They survived the coronavirus. Then they tested positive again. Why?|date=13 March 2020|website=Los Angeles Times|access-date=15 March 2020|archive-url=https://web.archive.org/web/20200314220822/https://www.latimes.com/world-nation/story/2020-03-13/china-japan-korea-coronavirus-reinfection-test-positive|archive-date=14 March 2020|url-status=live}}</ref><ref>{{cite web |url= https://www.caixinglobal.com/2020-02-26/14-of-recovered-covid-19-patients-in-guangdong-tested-positive-again-101520415.html|title=14% of Recovered Covid-19 Patients in Guangdong Tested Positive Again| publisher= Caixin Global|website= caixinglobal.com|access-date=15 March 2020|archive-url= https://web.archive.org/web/20200303181249/https://www.caixinglobal.com/2020-02-26/14-of-recovered-covid-19-patients-in-guangdong-tested-positive-again-101520415.html|archive-date=3 March 2020|url-status=live}}</ref><ref name="Omer2020">{{cite journal | vauthors = Omer SB, Malani P, Del Rio C | title = The COVID-19 Pandemic in the US: A Clinical Update | journal = JAMA | date = April 2020 | pmid = 32250388 | doi = 10.1001/jama.2020.5788 | doi-access = free }}</ref> However, these cases are believed to be lingering infection rather than reinfection,<ref name="Omer2020"/> or false positives due to remaining RNA fragments.<ref>{{citation |url=https://www.thetimes.co.uk/article/coronavirus-patients-cant-relapse-south-korean-scientists-believe-rkm8zm7d9 |title=Coronavirus patients can't relapse, South Korean scientists believe |newspaper=The Times | first = Richard Lloyd | last = Parry | name-list-format = vanc |date=30 April 2020}}</ref> An investigation by the [[Organization:Korea Centers for Disease Control and Prevention|Korean CDC]] of 285 individuals who tested positive for SARS-CoV-2 in PCR tests administered days or weeks after recovery from COVID-19 found no evidence that these individuals were contagious at this later time.<ref>{{Cite web|title=Findings from investigation and analysis of re-positive cases|url=https://www.cdc.go.kr/board/board.es?mid=a30402000000&bid=0030|last=|first=|date=19 May 2020|website=KCDC|language=en|url-status=live|archive-url=|archive-date=|access-date=23 May 2020}}</ref> Some other coronaviruses circulating in people are capable of reinfection after roughly a year.<ref>{{cite web|title=What if immunity to covid-19 doesn't last?|url=https://www.technologyreview.com/2020/04/27/1000569/how-long-are-people-immune-to-covid-19/|website=MIT Technology Review|access-date=1 May 2020}}</ref><ref>{{cite web|title=Direct observation of repeated infections with endemic coronaviruses|url=http://www.columbia.edu/~jls106/galanti_shaman_ms_supp.pdf|publisher=Department of Environmental Health Sciences, Mailman School of Public Health, [[Organization:Columbia University|Columbia University]]|website=Columbia University in the City of New York|access-date=2 May 2020|date=15 April 2020}}</ref>

==History==


The virus is thought to be natural and has an [[Biology:Zoonosis|animal origin]],<ref name="NM-20200317">{{cite journal | vauthors = Andersen KG, Rambaut A, Lipkin WI, Holmes EC, Garry RF | title = The proximal origin of SARS-CoV-2 | journal = Nature Medicine | volume = 26 | issue = 4 | pages = 450–452 | date = April 2020 | pmid = 32284615 | pmc = 7095063 | doi = 10.1038/s41591-020-0820-9 }}</ref> through [[Biology:Spillover infection|spillover infection]].<ref>{{cite web|url=https://nautil.us/issue/83/intelligence/the-man-who-saw-the-pandemic-coming|title=The Man Who Saw the Pandemic Coming|last=Berger|first=Kevin|name-list-format=vanc|date=12 March 2020|website=Nautilus|access-date=16 March 2020|archive-url=https://web.archive.org/web/20200315180124/http://nautil.us/issue/83/intelligence/the-man-who-saw-the-pandemic-coming|archive-date=15 March 2020|url-status=live}}</ref> The first known human infections were in China. A study of the first 41 cases of confirmed COVID‑19, published in January 2020 in ''The Lancet'', reported the earliest date of onset of symptoms as 1{{nbsp}}December 2019.<ref name="WuMarch2020">{{cite journal|vauthors=Wu YC, Chen CS, Chan YJ|date=March 2020|title=The outbreak of COVID-19: An overview|journal=Journal of the Chinese Medical Association|volume=83|issue=3|pages=217–220|doi=10.1097/JCMA.0000000000000270|pmc=7153464|pmid=32134861}}</ref><ref name="Wang24Jan2020">{{cite journal|vauthors=Wang C, Horby PW, Hayden FG, Gao GF|date=February 2020|title=A novel coronavirus outbreak of global health concern|url=https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30185-9/abstract|journal=Lancet|volume=395|issue=10223|pages=470–473|doi=10.1016/S0140-6736(20)30185-9|pmc=7135038|pmid=31986257|doi-access=free}}</ref><ref name="AutoDW-67">{{cite journal|last=Cohen|first=Jon|date=January 2020|title=Wuhan seafood market may not be source of novel virus spreading globally|url=https://www.sciencemag.org/news/2020/01/wuhan-seafood-market-may-not-be-source-novel-virus-spreading-globally|journal=Science|doi=10.1126/science.abb0611|name-list-format=vanc}}</ref> Official publications from the WHO reported the earliest onset of symptoms as 8{{nbsp}}December 2019.<ref>{{cite web|date=12 January 2020|title=Novel Coronavirus—China|url=https://www.who.int/csr/don/12-january-2020-novel-coronavirus-china/en/|website=[[Organization:World Health Organization|World Health Organization]] (WHO)}}</ref> Human-to-human transmission was confirmed by the WHO and Chinese authorities by 20 January 2020.<ref>{{cite news|last1=Kessler|first1=Glenn|date=17 April 2020|title=Trump's false claim that the WHO said the coronavirus was 'not communicable'|work={{wipe|The Washington Post}}|url=https://www.washingtonpost.com/politics/2020/04/17/trumps-false-claim-that-who-said-coronavirus-was-not-communicable/|url-status=live|access-date=17 April 2020|archive-url=https://archive.today/20200417193804/https://www.washingtonpost.com/politics/2020/04/17/trumps-false-claim-that-who-said-coronavirus-was-not-communicable/|archive-date=17 April 2020|name-list-format=vanc}}</ref><ref>{{cite news|last1=Kuo|first1=Lily|date=21 January 2020|title=China confirms human-to-human transmission of coronavirus|work={{wipe|The Guardian}}|url=https://www.theguardian.com/world/2020/jan/20/coronavirus-spreads-to-beijing-as-china-confirms-new-cases|access-date=18 April 2020|name-list-format=vanc}}</ref> According to official Chinese sources, these were mostly linked to the Huanan Seafood Wholesale Market, which also sold live animals.<ref name="characteristicsZH">{{cite journal|author1=Novel Coronavirus Pneumonia Emergency Response Epidemiology Team|date=February 2020|title=[The epidemiological characteristics of an outbreak of 2019 novel coronavirus diseases (COVID-19) in China]|journal=Zhonghua Liu Xing Bing Xue Za Zhi = Zhonghua Liuxingbingxue Zazhi|language=zh|volume=41|issue=2|pages=145–151|doi=10.3760/cma.j.issn.0254-6450.2020.02.003|pmid=32064853|s2cid=211133882}}</ref> In May 2020, George Gao, the director of the [[Organization:Chinese Center for Disease Control and Prevention|Chinese Center for Disease Control and Prevention]], said animal samples collected from the seafood market had tested negative for the virus, indicating that the market was the site of an early [[Biology:Superspreader|superspreading event]], but it was not the site of the initial outbreak.<ref>{{cite news|last=Areddy|first=James T.|date=26 May 2020|title=China Rules Out Animal Market and Lab as Coronavirus Origin|work={{wipe|The Wall Street Journal}}|url=https://www.wsj.com/articles/china-rules-out-animal-market-and-lab-as-coronavirus-origin-11590517508|accessdate=29 May 2020|url-access=subscription}}</ref> Traces of the virus have been found in wastewater that was collected from Milan and [[Place:Turin|Turin]], Italy, on 18 December 2019.<ref>{{cite news|last=Kelland|first=Kate|date=19 June 2020|title=Italy sewage study suggests COVID-19 was there in December 2019|work=Reuters|url=https://www.reuters.com/article/us-health-coronavirus-italy-sewage/italy-sewage-study-suggests-covid-19-was-there-in-december-2019-idUSKBN23Q1J9|access-date=23 June 2020}}</ref>

There are several theories about where the very first case (the so-called [[Medicine:Index case|patient zero]]) originated.<ref name="patientZero">{{cite news|last1=Duarte|first1=Fernando|date=24 February 2020|title=As the cases of coronavirus increase in China and around the world, the hunt is on to identify "patient zero".|work=BBC News Online|url=https://www.bbc.com/future/article/20200221-coronavirus-the-harmful-hunt-for-covid-19s-patient-zero|access-date=22 March 2020|name-list-format=vanc}}</ref> According to an unpublicised report from the Chinese government, the first case can be traced back to 17 November 2019; the person was a 55-year old citizen in the Hubei province. There were four men and five women reported to be infected in November, but none of them were "patient zero".<ref name="tracedback" /> By December 2019, the spread of infection was almost entirely driven by human-to-human transmission.<ref name="Epidemiology2020Feb17">{{cite journal|vauthors=Yanping Z, et al.|collaboration=The Novel Coronavirus Pneumonia Emergency Response Epidemiology Team|title=The Epidemiological Characteristics of an Outbreak of 2019 Novel Coronavirus Diseases (COVID-19)—China, 2020|url=http://weekly.chinacdc.cn/en/article/id/e53946e2-c6c4-41e9-9a9b-fea8db1a8f51|journal=China CDC Weekly|volume=2|issue=8|pages=113–122|date=17 February 2020|publisher=[[Organization:Chinese Center for Disease Control and Prevention|Chinese Center for Disease Control and Prevention]]|access-date=18 March 2020|archive-url=https://web.archive.org/web/20200219142101/http://weekly.chinacdc.cn/en/article/id/e53946e2-c6c4-41e9-9a9b-fea8db1a8f51|archive-date=19 February 2020|url-status=live}}</ref><ref name="Heymann Shindo 2020 pp. 542–45">{{cite journal | vauthors = Heymann DL, Shindo N | title = COVID-19: what is next for public health? | journal = Lancet | volume = 395 | issue = 10224 | pages = 542–545 | date = February 2020 | pmid = 32061313 | doi = 10.1016/S0140-6736(20)30374-3 | doi-access = free }}</ref> The number of coronavirus cases in Hubei gradually increased, reaching 60 by 20 December<ref>{{Cite web|last=March 2020|first=Jeanna Bryner-Live Science Editor-in-Chief 14|title=1st known case of coronavirus traced back to November in China|url=https://www.livescience.com/first-case-coronavirus-found.html|access-date=31 May 2020|website=livescience.com}}</ref> and at least 266 by 31 December.<ref>{{Cite web|last=Politics|first=Canadian|date=8 April 2020|title=The birth of a pandemic: How COVID-19 went from Wuhan to Toronto {{!}} National Post|url=https://nationalpost.com/news/politics/the-birth-of-a-pandemic-how-covid-19-went-from-wuhan-to-toronto|access-date=31 May 2020}}</ref> On 24 December, Wuhan Central Hospital sent a bronchoalveolar lavage fluid (BAL) sample from an unresolved clinical case to sequencing company Vision Medicals. On 27 and 28 December, Vision Medicals informed the Wuhan Central Hospital and the Chinese CDC of the results of the test, showing a new coronavirus.<ref name="caixintrace">{{Cite news|author=高昱|date=26 February 2020|title=独家 {{!}} 新冠病毒基因测序溯源：警报是何时拉响的|language=zh|trans-title=Exclusive {{!}} Tracing the New Coronavirus gene sequencing: when did the alarm sound|work=Caixin|url=http://china.caixin.com/2020-02-26/101520972.html|url-status=dead|access-date=1 March 2020|archive-url=https://web.archive.org/web/20200227094018/http://china.caixin.com/2020-02-26/101520972.html|archive-date=27 February 2020}}</ref> A pneumonia cluster of unknown cause was observed on 26 December and treated by the doctor Zhang Jixian in Hubei Provincial Hospital, who informed the Wuhan Jianghan CDC on 27 December.<ref>{{Cite web|author1=路子康|title=最早上报疫情的她，怎样发现这种不一样的肺炎|url=https://news.china.com/zw/news/13000776/20200209/37780703.html|archive-url=https://web.archive.org/web/20200302165302/https://news.china.com/zw/news/13000776/20200209/37780703.html|archive-date=2 March 2020|accessdate=11 February 2020|website=中国网新闻|location=北京|language=zh-cn}}</ref> On 30 December, a test report addressed to Wuhan Central Hospital, from company CapitalBio Medlab, stated an erroneous positive result for [[Medicine:SARS|SARS]], causing a group of doctors at Wuhan Central Hospital to alert their colleagues and relevant hospital authorities of the result. That evening, the Wuhan Municipal Health Commission issued a notice to various medical institutions on "the treatment of pneumonia of unknown cause".<ref name="promedmail6864153">{{cite web|title=Undiagnosed pneumonia—China (HU): RFI|url=https://promedmail.org/promed-post/?id=6864153|accessdate=7 May 2020|website=ProMED Mail|publisher=ProMED}}</ref> Eight of these doctors, including Li Wenliang (punished on 3{{nbsp}}January),<ref name="siStf">{{cite news|date=7 February 2020|title='Hero who told the truth': Chinese rage over coronavirus death of whistleblower doctor|work={{wipe|The Guardian}}|url=https://www.theguardian.com/global-development/2020/feb/07/coronavirus-chinese-rage-death-whistleblower-doctor-li-wenliang}}</ref> were later admonished by the police for spreading false rumours, and another, Ai Fen, was reprimanded by her superiors for raising the alarm.<ref name="20200311theguardian">{{cite news|last1=Kuo|first1=Lily|date=11 March 2020|title=Coronavirus: Wuhan doctor speaks out against authorities|work=The Guardian|location=London|url=https://www.theguardian.com/world/2020/mar/11/coronavirus-wuhan-doctor-ai-fen-speaks-out-against-authorities|name-list-format=vanc}}</ref>

The Wuhan Municipal Health Commission made the first public announcement of a pneumonia outbreak of unknown cause on 31 December, confirming 27 cases<ref name="AutoDW-69">{{cite web|title=Novel Coronavirus|url=https://www.who.int/westernpacific/emergencies/novel-coronavirus|url-status=live|archive-url=https://web.archive.org/web/20200202151307/https://www.who.int/westernpacific/emergencies/novel-coronavirus|archive-date=2 February 2020|access-date=6 February 2020|work=[[Organization:World Health Organization|World Health Organization]] (WHO)}}</ref><ref>{{cite news|date=31 December 2019|title=武汉现不明原因肺炎 官方确认属实：已经做好隔离|publisher=Xinhua Net 新華網|url=https://news.163.com/19/1231/10/F1NGTJNJ00019K82.html|access-date=31 March 2020}}</ref><ref name="AutoDW-68">{{cite web|date=31 December 2019|title=Archived copy|script-title=zh:武汉市卫健委关于当前我市肺炎疫情的情况通报|url=http://wjw.wuhan.gov.cn/front/web/showDetail/2019123108989|url-status=dead|archive-url=https://web.archive.org/web/20200109215413/http://wjw.wuhan.gov.cn/front/web/showDetail/2019123108989|archive-date=9 January 2020|access-date=8 February 2020|work=WJW.Wuhan.gov.cn|publisher=Wuhan Municipal Health Commission|language=zh}}</ref>—enough to trigger an investigation.<ref name="bbc50984025">{{Cite news|date=3 January 2020|title=Mystery pneumonia virus probed in China|work=BBC News Online|url=https://www.bbc.com/news/world-asia-china-50984025|url-status=live|access-date=29 January 2020|archive-url=https://web.archive.org/web/20200105051949/https://www.bbc.com/news/world-asia-china-50984025|archive-date=5 January 2020}}</ref>

During the early stages of the outbreak, the number of cases doubled approximately every seven and a half days.<ref name="Qun29Jan2020">{{cite journal|display-authors=6|vauthors=Li Q, Guan X, Wu P, Wang X, Zhou L, Tong Y, Ren R, Leung KS, Lau EH, Wong JY, Xing X, Xiang N, Wu Y, Li C, Chen Q, Li D, Liu T, Zhao J, Liu M, Tu W, Chen C, Jin L, Yang R, Wang Q, Zhou S, Wang R, Liu H, Luo Y, Liu Y, Shao G, Li H, Tao Z, Yang Y, Deng Z, Liu B, Ma Z, Zhang Y, Shi G, Lam TT, Wu JT, Gao GF, Cowling BJ, Yang B, Leung GM, Feng Z|date=March 2020|title=Early Transmission Dynamics in Wuhan, China, of Novel Coronavirus-Infected Pneumonia|journal=New England Journal of Medicine|volume=382|issue=13|pages=1199–1207|doi=10.1056/NEJMoa2001316|pmc=7121484|pmid=31995857|doi-access=free}}</ref> In early and mid-January 2020, the virus spread to other Chinese provinces, helped by the Chinese New Year migration and Wuhan being a transport hub and major rail interchange.<ref name="WHO report 28 February 2020">{{cite web|author=WHO–China Joint Mission|date=16–24 February 2020|title=Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19)|url=https://www.who.int/docs/default-source/coronaviruse/who-china-joint-mission-on-covid-19-final-report.pdf|access-date=8 March 2020|work=[[Organization:World Health Organization|World Health Organization]]}}</ref> On 20 January, China reported nearly 140 new cases in one day, including two people in Beijing and one in Shenzhen.<ref name="france2420200120">{{Cite news|date=20 January 2020|title=China confirms sharp rise in cases of SARS-like virus across the country|url=https://www.france24.com/en/20200120-china-confirms-sharp-rise-in-cases-of-sars-like-virus-across-the-country|url-status=live|access-date=20 January 2020|archive-url=https://web.archive.org/web/20200120055618/https://www.france24.com/en/20200120-china-confirms-sharp-rise-in-cases-of-sars-like-virus-across-the-country|archive-date=20 January 2020}}</ref> Later official data shows 6,174 people had already developed symptoms by then,<ref name="Epidemiology17Feb2020">{{Cite journal|author=The Novel Coronavirus Pneumonia Emergency Response Epidemiology Team|date=17 February 2020|title=The Epidemiological Characteristics of an Outbreak of 2019 Novel Coronavirus Diseases (COVID-19)—China, 2020|url=http://weekly.chinacdc.cn/en/article/id/e53946e2-c6c4-41e9-9a9b-fea8db1a8f51|journal=China CDC Weekly|volume=2|issue=8|pages=113–122|access-date=18 March 2020}}</ref> and more may have been infected.<ref name="flattery">{{cite news|date=25 April 2020|title=Flattery and foot dragging: China's influence over the WHO under scrutiny|work=The Globe and Mail|url=https://www.theglobeandmail.com/world/article-flattery-and-foot-dragging-chinas-influence-over-the-who-under/}}</ref> A report in ''The Lancet'' on 24 January indicated human transmission, strongly recommended [[Social:Personal protective equipment|personal protective equipment]] for health workers, and said testing for the virus was essential due to its "pandemic potential".<ref name="Huang24Jan20202">{{cite journal|display-authors=6|vauthors=Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y, Zhang L, Fan G, Xu J, Gu X, Cheng Z, Yu T, Xia J, Wei Y, Wu W, Xie X, Yin W, Li H, Liu M, Xiao Y, Gao H, Guo L, Xie J, Wang G, Jiang R, Gao Z, Jin Q, Wang J, Cao B|date=24 January 2020|title=Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China|url=https://www.thelancet.com/action/showPdf?pii=S0140-6736%2820%2930183-5|journal=Lancet|volume=395|issue=10223|pages=497–506|doi=10.1016/S0140-6736(20)30183-5|pmc=7159299|pmid=31986264|doi-access=free}}</ref><ref name="Horton 18 March">{{cite web|last1=Horton|first1=Richard|date=18 March 2020|title=Scientists have been sounding the alarm on coronavirus for months. Why did Britain fail to act?|url=http://www.theguardian.com/commentisfree/2020/mar/18/coronavirus-uk-expert-advice-wrong|access-date=23 April 2020|website=The Guardian}}</ref> On 30 January, the WHO declared the coronavirus a [[Social:Public health emergency of international concern|public health emergency of international concern]].<ref name="flattery" /> By this time, the outbreak spread by a factor of 100 to 200 times.<ref>{{Cite web|date=2 June 2020|title=China delayed releasing coronavirus info, frustrating WHO|url=https://apnews.com/3c061794970661042b18d5aeaaed9fae|access-date=3 June 2020|website=AP NEWS}}</ref>

On 31 January 2020, Italy had its first confirmed cases, two tourists from China.<ref name="Corriere_20Jan">{{cite web|date=31 January 2020|title=Coronavirus: Primi due casi in Italia|trans-title=Coronavirus: First two cases in Italy|url=https://www.corriere.it/cronache/20_gennaio_30/coronavirus-italia-corona-9d6dc436-4343-11ea-bdc8-faf1f56f19b7.shtml|access-date=31 January 2020|work=Corriere della sera|language=it}}</ref> As of 13 March 2020, the WHO considered Europe the active centre of the pandemic.<ref name="nypost20200313">{{cite news|last1=Fredericks|first1=Bob|date=13 March 2020|title=WHO says Europe is new epicenter of coronavirus pandemic|work=New York Post|url=https://nypost.com/2020/03/13/who-says-europe-is-new-epicenter-of-coronavirus-pandemic/|accessdate=9 May 2020|name-list-format=vanc}}</ref> On 19 March 2020, Italy overtook China as the country with the most deaths.<ref name="sky11960412">{{cite web|title=Coronavirus: Number of COVID-19 deaths in Italy surpasses China as total reaches 3,405|url=https://news.sky.com/story/coronavirus-number-of-covid-19-deaths-in-italy-surpasses-china-as-total-reaches-3-405-11960412|accessdate=7 May 2020|publisher=Sky News}}</ref> By 26 March, the United States had overtaken China and Italy with the highest number of confirmed cases in the world.<ref name="NYT-20200326">{{cite news|last1=McNeil Jr.|first1=Donald G.|date=26 March 2020|title=The U.S. Now Leads the World in Confirmed Coronavirus Cases|work={{wipe|The New York Times}}|url=https://www.nytimes.com/2020/03/26/health/usa-coronavirus-cases.html|access-date=27 March 2020|name-list-format=vanc}}</ref> Research on [[Biology:Severe acute respiratory syndrome coronavirus 2|coronavirus genomes]] indicates the majority of COVID-19 cases in New York came from European travellers, rather than directly from China or any other Asian country.<ref name="20200408nytimes">{{cite news|date=8 April 2020|title=Studies Show N.Y. Outbreak Originated in Europe|work={{wipe|The New York Times}}|url=https://www.nytimes.com/2020/04/08/us/coronavirus-live-updates.html}}</ref> Retesting of prior samples found a person in France who had the virus on 27 December 2019<ref name="France-retest">{{cite news|last1=Irish|first1=John|date=4 May 2020|title=After retesting samples, French hospital discovers COVID-19 case from December|agency={{wipe|Reuters}}|editor-last=Lough|editor-first=Richard|url=https://www.reuters.com/article/us-health-coronavirus-france-idUSKBN22G20L|access-date=4 May 2020|editor2-last=Graff|editor2-first=Peter|name-list-format=vanc}}</ref><ref name=":22">{{cite journal|vauthors=Deslandes A, Berti V, Tandjaoui-Lambotte Y, Alloui C, Carbonnelle E, Zahar JR, Brichler S, Cohen Y|date=3 May 2020|title=SARS-COV-2 was already spreading in France in late December 2019|journal=International Journal of Antimicrobial Agents|volume=55|issue=6|page=106006|doi=10.1016/j.ijantimicag.2020.106006|pmc=7196402|pmid=32371096}}</ref> and a person in the United States who died from the disease on 6{{nbsp}}February 2020.<ref name="PBS-2wks">{{cite web|date=22 April 2020|title=2 died with coronavirus weeks before 1st U.S. virus death|url=https://www.pbs.org/newshour/nation/2-died-with-coronavirus-weeks-before-1st-u-s-virus-death|access-date=23 April 2020|website=PBS NewsHour}}</ref>

On 11 June 2020, after 55 days without a locally transmitted case,<ref name=":42">{{Cite web|last=|first=|date=16 June 2020|title=Beijing Covid-19 outbreak puts food markets back in infection focus|url=https://www.scmp.com/news/china/society/article/3089161/beijing-covid-19-outbreak-puts-food-markets-back-infection-focus|url-status=live|archive-url=https://web.archive.org/web/20200616040222/https://www.scmp.com/news/china/society/article/3089161/beijing-covid-19-outbreak-puts-food-markets-back-infection-focus|archive-date=18 June 2020|access-date=17 June 2020|website=South China Morning Post}}</ref> Beijing reported the first COVID-19 case, followed by two more cases on 12 June.<ref>{{Cite web|last=|first=|date=|title=北京连续确诊3例新冠患者 新发地批发市场暂停营业|url=http://www.caixin.com/2020-06-12/101566522.html|url-status=live|archive-url=https://web.archive.org/web/20200613014454/http://www.caixin.com/2020-06-12/101566522.html|archive-date=18 June 2020|access-date=17 June 2020|website=www.caixin.com}}</ref> By 15 June, 79 cases were officially confirmed.<ref>{{Cite web|first=Nectar |last=Gan|date=|title=China's new coronavirus outbreak sees Beijing adopt 'wartime' measures|url=https://www.cnn.com/2020/06/15/asia/coronavirus-beijing-outbreak-intl-hnk/index.html|url-status=live|archive-url=https://web.archive.org/web/20200616001340/https://www.cnn.com/2020/06/15/asia/coronavirus-beijing-outbreak-intl-hnk/index.html|archive-date=18 June 2020|access-date=17 June 2020|website=CNN}}</ref> Most of these patients went to Xinfadi Wholesale Market.<ref name=":42" /><ref>{{Cite web|title=Beijing logs record 36 COVID-19 cases, linked to market cluster|url=https://www.channelnewsasia.com/news/asia/covid-19-cases-china-beijing-market-cluster-12833874|access-date=17 June 2020|website=CNA}}</ref>

==Epidemiology==
Several measures are commonly used to quantify mortality.<ref>{{cite web|url=https://www.cdc.gov/csels/dsepd/ss1978/lesson3/section3.html|title=Principles of Epidemiology {{!}} Lesson 3—Section 3|date=18 February 2019|website=www.cdc.gov|access-date=28 March 2020|archive-url=https://web.archive.org/web/20200228150607/https://www.cdc.gov/csels/dsepd/ss1978/lesson3/section3.html|archive-date=28 February 2020|url-status=live}}</ref> These numbers vary by region and over time and are influenced by the volume of testing, healthcare system quality, treatment options, time since the initial outbreak, and population characteristics such as age, sex, and overall health.<ref>{{cite web |url=https://ourworldindata.org/covid-mortality-risk |title=What do we know about the risk of dying from COVID-19? |last1=Ritchie |first1=Hannah |last2=Roser |first2=Max | name-list-format = vanc |date=25 March 2020 |editor-last=Chivers |editor-first=Tom |website=[[Organization:Our World in Data|Our World in Data]] |url-status=live |access-date=28 March 2020 |archive-url=https://web.archive.org/web/20200328192730/https://ourworldindata.org/covid-mortality-risk |archive-date=28 March 2020 }}</ref>

The death-to-case ratio reflects the number of deaths divided by the number of diagnosed cases within a given time interval. Based on Johns Hopkins University statistics, the global death-to-case ratio is {{Cases in the COVID-19 pandemic|ratio|editlink=|ref=no}} ({{Cases in the COVID-19 pandemic|deaths|editlink=|ref=no}}/{{Cases in the COVID-19 pandemic|confirmed|editlink=|ref=no}}) as of {{Cases in the COVID-19 pandemic|date|editlink=|ref=no}}.{{Cases in the COVID-19 pandemic|ref=yes}} The number varies by region.<ref>{{cite journal | vauthors = Lazzerini M, Putoto G | title = COVID-19 in Italy: momentous decisions and many uncertainties | journal = The Lancet. Global Health | volume = 8 | issue = 5 | pages = e641–e642 | date = May 2020 | pmid = 32199072 | pmc = 7104294 | doi = 10.1016/S2214-109X(20)30110-8 | url = https://www.thelancet.com/journals/langlo/article/PIIS2214-109X(20)30110-8/abstract }}</ref>

Other measures include the [[Medicine:Case fatality rate|case fatality rate]] (CFR), which reflects the percent of ''diagnosed'' individuals who die from a disease, and the infection fatality rate (IFR), which reflects the percent of ''infected'' individuals (diagnosed and undiagnosed) who die from a disease. These statistics are not time-bound and follow a specific population from infection through case resolution. Many academics have attempted to calculate these numbers for specific populations.<ref>{{cite web |url=https://ourworldindata.org/covid-mortality-risk |title=What do we know about the risk of dying from COVID-19? |website=Our World in Data |access-date=28 March 2020 |archive-url=https://web.archive.org/web/20200328192730/https://ourworldindata.org/covid-mortality-risk |archive-date=28 March 2020 |url-status=live }}</ref>

Outbreaks have occurred in prisons due to crowding and an inability to enforce adequate social distancing.<ref name="Hawks2020"/><ref>{{cite web | first=David | last=Waldstein | name-list-format = vanc | title=To Fight Virus in Prisons, C.D.C. Suggests More Screenings | website={{wipe|The New York Times}} | date=6 May 2020 | url=https://www.nytimes.com/2020/05/06/health/coronavirus-prisons-cdc.html | access-date=14 May 2020}}</ref> In the United States, the prisoner population is aging and many of them are at high risk for poor outcomes from COVID‑19 due to high rates of coexisting heart and lung disease, and poor access to high-quality healthcare.<ref name="Hawks2020">{{cite journal | vauthors = Hawks L, Woolhandler S, McCormick D | title = COVID-19 in Prisons and Jails in the United States | journal = JAMA Internal Medicine | date = April 2020 | pmid = 32343355 | doi = 10.1001/jamainternmed.2020.1856 | doi-access = free }}</ref>

{{Multiple image
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| image1 =Total-cases-covid-19-who.png| caption1 =Total confirmed cases over time
| image2 =Total-deaths-covid-19-who (1).png| caption2 =Total deaths over time
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| image1 =Total-confirmed-cases-of-covid-19-per-million-people.png| caption1 =Total confirmed cases of COVID‑19 per million people<ref>{{cite web |title=Total confirmed cases of COVID-19 per million people |url=https://ourworldindata.org/grapher/total-confirmed-cases-of-covid-19-per-million-people |website=Our World in Data |access-date=10 April 2020 |archive-url=https://web.archive.org/web/20200319163452/https://ourworldindata.org/grapher/total-confirmed-cases-of-covid-19-per-million-people |archive-date=19 March 2020 |url-status=live }}</ref>
| image2 =Total-covid-deaths-per-million.png| caption2 =Total confirmed deaths due to COVID‑19 per million people<ref>{{cite web |title=Total confirmed deaths due to COVID-19 per million people |url=https://ourworldindata.org/grapher/total-covid-deaths-per-million |website=Our World in Data |access-date=10 April 2020 |archive-url=https://web.archive.org/web/20200319163452/https://ourworldindata.org/grapher/total-covid-deaths-per-million |archive-date=19 March 2020 |url-status=live }}</ref>
}}

===Infection fatality rate===
Infection fatality rate (or infection fatality ratio) is distinguished from [[Medicine:Case fatality rate|case fatality rate]]. The case fatality rate ("CFR") for a disease is the proportion of deaths from the disease compared to the total number of people ''diagnosed'' with the disease (within a certain period of time). The infection fatality ratio ("IFR"), in contrast, is the proportion of deaths among all the ''infected'' individuals. IFR, unlike CFR, attempts to account for all asymptomatic and undiagnosed infections.

[[Organization:Our World in Data|Our World in Data]] states that, as of 25 March 2020, the infection fatality rate (IFR) for coronavirus cannot be accurately calculated.<ref>{{cite web |title=What do we know about the risk of dying from COVID-19? |url=https://ourworldindata.org/covid-mortality-risk |website=Our World in Data |access-date=23 April 2020}}</ref> In February, the World Health Organization reported estimates of IFR between 0.33% and 1%.<ref>{{cite web |title=Coronavirus disease 2019 (COVID-19) Situation Report—30 |url=https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200219-sitrep-30-covid-19.pdf |access-date=3 June 2020 |date=19 February 2020}}</ref><ref>{{cite web |title=Coronavirus disease 2019 (COVID-19) Situation Report—31 |url=https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200220-sitrep-31-covid-19.pdf |access-date=23 April 2020 |date=20 February 2020}}</ref> On 2 July, The WHO's Chief Scientist reported that the average IFR estimate presented at a two-day WHO expert forum was about 0.6%.<ref name="NYT-20200704dm">{{cite news |last=McNeil Jr. |first=Donald G. |title=The Pandemic’s Big Mystery: How Deadly Is the Coronavirus? – Even with more than 500,000 dead worldwide, scientists are struggling to learn how often the virus kills. Here’s why. |url=https://www.nytimes.com/2020/07/04/health/coronavirus-death-rate.html |date=4 July 2020 |work={{wipe|The New York Times}} |accessdate=6 July 2020 }}</ref><ref>{{cite news |title=Global Research and Innovation Forum on COVID-19: Virtual Press Conference |url=https://www.who.int/docs/default-source/coronaviruse/virtual-press-conference---2-july---update-on-covid-19-r-d.pdf |publisher=World Health Organization |date=July 2, 2020}}</ref>

The CDC estimates for planning purposes that the infection fatality rate is 0.65% and that 40% of infected individuals are asymptomatic, suggesting a fatality rate among those who are symptomatic of 1.08% (.65/60) (as of 10 July).<ref>{{cite web |title=Coronavirus Disease 2019 (COVID-19) |url=https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scenarios.html |website=U.S. Centers for Disease Control and Prevention (CDC) |accessdate=22 May 2020 |date=11 February 2020}}</ref><ref>{{Cite web|last=Gan|first=Nectar|last2=McKeehan|first2=Brett|date=2020-07-11|title=CDC now estimates that 40% of people infected with Covid-19 don't have any symptoms|url=https://edition.cnn.com/world/live-news/coronavirus-pandemic-07-11-20-intl/h_d6a63735c82f708ffdcff33082da393b|url-status=live|archive-url=|archive-date=|access-date=2020-07-18|website=CNN|language=en}}</ref> According to the [[Organization:University of Oxford|University of Oxford]] [[Organization:Centre for Evidence-Based Medicine|Centre for Evidence-Based Medicine]] (CEBM), random antibody testing in Germany suggested a national IFR of 0.37% (0.12% to 0.87%).<ref name="cebm-global-cf">{{cite web|date=17 March 2020|title=Global Covid-19 Case Fatality Rates|url=https://www.cebm.net/covid-19/global-covid-19-case-fatality-rates/|url-status=live|archive-url=|archive-date=|access-date=10 April 2020|website=[[Organization:Centre for Evidence-Based Medicine|Centre for Evidence-Based Medicine]]}}</ref><ref>{{cite web|url=https://towardsdatascience.com/gangelt-a-representative-study-on-the-lethality-of-covid-19-5d877dbd6e55|title=Gangelt–A representative study on the lethality of COVID-19|last=Haake|first=Daniel| name-list-format = vanc |date=24 April 2020|website=Medium|access-date=27 April 2020}}</ref><ref>{{cite web|url=https://www.sciencemag.org/news/2020/04/antibody-surveys-suggesting-vast-undercount-coronavirus-infections-may-be-unreliable|title=Antibody surveys suggesting vast undercount of coronavirus infections may be unreliable|last=Vogel |first=Gretchen | name-list-format = vanc |date=21 April 2020|website=Science {{!}} AAAS|access-date=29 April 2020 }}</ref> To get a better view on the number of people infected, {{as of|2020|04|lc=yes}}, initial antibody testing had been carried out, but peer-reviewed scientific analyses had not yet been published.<ref>{{cite web|url=https://www.bloomberg.com/opinion/articles/2020-04-24/is-coronavirus-worse-than-the-flu-blood-studies-say-yes-by-far|title=The Coronavirus Isn't Just the Flu, Bro | date=|website=www.bloomberg.com|url-status=live|archive-url=|archive-date=|access-date=26 April 2020}}</ref><ref>{{cite web|url=https://arstechnica.com/science/2020/04/experts-demolish-studies-suggesting-covid-19-is-no-worse-than-flu/|title=Experts demolish studies suggesting COVID-19 is no worse than flu|last=Mole|first=Beth| name-list-format = vanc |date=24 April 2020|website=[[Ars Technica]]|access-date=26 April 2020}}</ref> On 1{{nbsp}}May antibody testing in New York City suggested an IFR of 0.86%.<ref>{{cite ssrn|last=Wilson|first=Linus|date=May 2020|title=SARS-CoV-2, COVID-19, Infection Fatality Rate (IFR) Implied by the Serology, Antibody, Testing in New York City |ssrn=3590771}}</ref>

Firm lower limits of infection fatality rates have been established in a number of locations such as New York City and Bergamo in Italy since the IFR cannot be less than the population fatality rate. As of 10{{nbsp}}July, in {{wipe|New York City}}, with a population of 8.4{{nbsp}}million, 23,377 individuals (18,758 confirmed and 4,619 probable) have died with COVID-19 (0.28% of the population).<ref>{{cite web | title = COVID-19: Data |url=https://www1.nyc.gov/site/doh/covid/covid-19-data.page | publisher = City of New York }}</ref> In Bergamo province, 0.57% of the population has died.<ref>{{cite web|url=https://medium.com/bccp-uc-berkeley/how-deadly-is-covid-19-data-science-offers-answers-from-italy-mortality-data-58abedf824cf|title=How deadly is COVID-19? Data Science offers answers from Italy mortality data.|last=Modi|first=Chirag| name-list-format = vanc |date=21 April 2020 |website=Medium |access-date=23 April 2020 }}</ref>

===Sex differences===
{{main|Social:Gendered impact of the COVID-19 pandemic}}
Early reviews of epidemiologic data showed greater impact of the pandemic and a higher mortality rate in men in China and Italy.<ref name="lancet">{{cite journal | vauthors = Wenham C, Smith J, Morgan R | title = COVID-19: the gendered impacts of the outbreak | journal = Lancet | volume = 395 | issue = 10227 | pages = 846–848 | date = March 2020 | pmid = 32151325 | pmc = 7124625 | doi = 10.1016/S0140-6736(20)30526-2 | doi-access = free }}</ref><ref name="chinamortality">{{cite journal | vauthors = Chen N, Zhou M, Dong X, Qu J, Gong F, Han Y, Qiu Y, Wang J, Liu Y, Wei Y, Xia J, Yu T, Zhang X, Zhang L | display-authors = 6 | title = Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study | journal = Lancet | volume = 395 | issue = 10223 | pages = 507–513 | date = February 2020 | pmid = 32007143 | pmc = 7135076 | doi = 10.1016/S0140-6736(20)30211-7 | doi-access = free }}</ref><ref>{{cite journal | title = [The epidemiological characteristics of an outbreak of 2019 novel coronavirus diseases (COVID-19) in China] | language = ch | journal = Zhonghua Liu Xing Bing Xue Za Zhi = Zhonghua Liuxingbingxue Zazhi | volume = 41 | issue = 2 | pages = 145–151 | date = February 2020 | pmid = 32064853 | doi = 10.3760/cma.j.issn.0254-6450.2020.02.003 | url = http://rs.yiigle.com/yufabiao/1181998.htm | author1 = Novel Coronavirus Pneumonia Emergency Response Epidemiology Team | s2cid = 211133882 }}</ref> The [[Organization:Chinese Center for Disease Control and Prevention|Chinese Center for Disease Control and Prevention]] reported the death rate was 2.8 percent for men and 1.7 percent for women.<ref>{{cite journal | title=The Epidemiological Characteristics of an Outbreak of 2019 Novel Coronavirus Diseases (COVID-19) | journal=China CDC Weekly | volume=2 | issue=8 | date=1 February 2020 | issn=2096-7071 | doi=10.46234/ccdcw2020.032 | pages=113–122 | url=http://weekly.chinacdc.cn/en/article/id/e53946e2-c6c4-41e9-9a9b-fea8db1a8f51 | access-date=15 June 2020}}</ref> Later reviews in June 2020 indicated that there is no significant difference in susceptibility or in CFR between genders.<ref>{{cite journal | title=Prevalence and severity of corona virus disease 2019 (COVID-19): A systematic review and meta-analysis | journal=Journal of Clinical Virology | volume=127 | date=1 June 2020 | issn=1386-6532 | doi=10.1016/j.jcv.2020.104371 | url=https://www.sciencedirect.com/science/article/pii/S138665322030113X | access-date=15 June 2020 | page=104371| last1=Hu | first1=Yong | last2=Sun | first2=Jiazhong | last3=Dai | first3=Zhe | last4=Deng | first4=Haohua | last5=Li | first5=Xin | last6=Huang | first6=Qi | last7=Wu | first7=Yuwen | last8=Sun | first8=Li | last9=Xu | first9=Yancheng | pmid=32315817 | pmc=7195434 }}</ref><ref>{{cite journal | title=Clinical characteristics of coronavirus disease 2019 (COVID-19) in China: A systematic review and meta-analysis | journal=Journal of Infection | volume=80 | issue=6 | date=1 June 2020 | issn=0163-4453 | doi=10.1016/j.jinf.2020.03.041 | pages=656–665 | url=https://www.sciencedirect.com/science/article/pii/S0163445320301705 | access-date=15 June 2020| last1=Fu | first1=Leiwen | last2=Wang | first2=Bingyi | last3=Yuan | first3=Tanwei | last4=Chen | first4=Xiaoting | pmid=32283155 | pmc=7151416 }}</ref> One review acknowledges the different mortality rates in Chinese men, suggesting that it may be attributable to lifestyle choices such as smoking and drinking alcohol rather than genetic factors.<ref>{{cite journal | title=COVID-19 pathophysiology: A review | journal=Clinical Immunology | volume=215 | date=1 June 2020 | issn=1521-6616 | doi=10.1016/j.clim.2020.108427 | url=https://www.sciencedirect.com/science/article/pii/S152166162030262X#bb0125 | access-date=15 June 2020 | page=108427| last1=Yuki | first1=Koichi | last2=Fujiogi | first2=Miho | last3=Koutsogiannaki | first3=Sophia | s2cid=216028003 | pmid=32325252 | pmc=7169933 }}</ref> Sex-based immunological differences, lesser prevalence of smoking in women and men developing co-morbid conditions such as hypertension at a younger age than women could have contributed to the higher mortality in men.<ref name = nyt-italy>{{cite news |last1=Rabin |first1=Roni Caryn |title=In Italy, Coronavirus Takes a Higher Toll on Men |url=https://www.nytimes.com/2020/03/20/health/coronavirus-italy-men-risk.html |accessdate=7 April 2020 |work=The New York Times |date=20 March 2020}}</ref> In Europe, 57% of the infected people were men and 72% of those died with COVID-19 were men.<ref>{{cite web |title=COVID-19 weekly surveillance report |url=http://www.euro.who.int/en/health-topics/health-emergencies/coronavirus-covid-19/weekly-surveillance-report |website=www.euro.who.int |accessdate=7 April 2020}}</ref> As of April 2020, the US government is not tracking sex-related data of COVID-19 infections.<ref name="nytimesus">{{cite news |last1=Gupta |first1=Alisha Haridasani |title=Does Covid-19 Hit Women and Men Differently? U.S. Isn't Keeping Track |url=https://www.nytimes.com/2020/04/03/us/coronavirus-male-female-data-bias.html |accessdate=7 April 2020 |work=The New York Times |date=3 April 2020}}</ref> Research has shown that viral illnesses like Ebola, HIV, influenza and SARS affect men and women differently.<ref name="nytimesus"/>

{| role="presentation" class="wikitable mw-collapsible mw-collapsed"
|+ class="nowrap" | '''Estimated prognosis by age and sex based on cases from France and Diamond Princess ship'''<ref>{{Cite journal|last1=Salje|first1=Henrik|last2=Tran Kiem|first2=Cécile|last3=Lefrancq|first3=Noémie|last4=Courtejoie|first4=Noémie|last5=Bosetti|first5=Paolo|last6=Paireau|first6=Juliette|last7=Andronico|first7=Alessio|last8=Hozé|first8=Nathanaël|last9=Richet|first9=Jehanne|last10=Dubost|first10=Claire-Lise|last11=Le Strat|first11=Yann|date=13 May 2020|title=Estimating the burden of SARS-CoV-2 in France|journal=Science|language=en|doi=10.1126/science.abc3517|pmid=32404476|pmc=7223792|doi-access=free|issn=0036-8075|at=Table S1 and S2 in Supplementary Materials}}</ref>
|-
!colspan="10| Percent of infected people who are hospitalized
|-
!
! 0–19
! 20–29
! 30–39
! 40–49
! 50–59
! 60–69
! 70–79
! 80+
! Total
|-
! Female
|{{shade|align=center|0.2}}<br /><small>(0.1–0.3)</small>
|{{shade|align=center|0.6}}<br /><small>(0.3–0.9)</small>
|{{shade|align=center|1.1}}<br /><small>(0.7–1.8)</small>
|{{shade|align=center|1.6}}<br /><small>(0.9–2.4)</small>
|{{shade|align=center|3.2}}<br /><small>(1.9–4.9)</small>
|{{shade|align=center|6.2}}<br /><small>(3.7–9.6)</small>
|{{shade|align=center|9.6}}<br /><small>(5.7–14.8)</small>
|{{shade|align=center|23.6}}<br /><small>(14.0–36.4)</small>
|{{shade|align=center|3.2}}<br /><small>(1.9–5.0)</small>
|-
! Male
|{{shade|align=center|0.2}}<br /><small>(0.1–0.3)</small>
|{{shade|align=center|0.7}}<br /><small>(0.4–1.1)</small>
|{{shade|align=center|1.4}}<br /><small>(0.9–2.2)</small>
|{{shade|align=center|1.9}}<br /><small>(1.1–3.0)</small>
|{{shade|align=center|3.9}}<br /><small>(2.3–6.1)</small>
|{{shade|align=center|8.1}}<br /><small>(4.8–12.6)</small>
|{{shade|align=center|13.4}}<br /><small>(8.0–20.7)</small>
|{{shade|align=center|45.9}}<br /><small>(27.3–70.9)</small>
|{{shade|align=center|4.0}}<br /><small>(2.4–6.2)</small>
|-
! Total
|{{shade|align=center|0.2}}<br /><small>(0.1–0.3)</small>
|{{shade|align=center|0.6}}<br /><small>(0.4–1.0)</small>
|{{shade|align=center|1.3}}<br /><small>(0.8–2.0)</small>
|{{shade|align=center|1.7}}<br /><small>(1.0–2.7)</small>
|{{shade|align=center|3.5}}<br /><small>(2.1–5.4)</small>
|{{shade|align=center|7.1}}<br /><small>(4.2–11.0)</small>
|{{shade|align=center|11.3}}<br /><small>(6.7–17.5)</small>
|{{shade|align=center|32.0}}<br /><small>(19.0–49.4)</small>
|{{shade|align=center|3.6}}<br /><small>(2.1–5.6)</small>
|-
!colspan="10| Percent of hospitalized people who go to Intensive Care Unit
|-
!
! 0–19
! 20–29
! 30–39
! 40–49
! 50–59
! 60–69
! 70–79
! 80+
! Total
|-
! Female
|{{shade|align=center|16.7}}<br /><small>(14.4–19.2)</small>
|{{shade|align=center|8.6}}<br /><small>(7.5–9.9)</small>
|{{shade|align=center|11.9}}<br /><small>(10.9–13.0)</small>
|{{shade|align=center|16.6}}<br /><small>(15.6–17.7)</small>
|{{shade|align=center|20.7}}<br /><small>(19.8–21.7)</small>
|{{shade|align=center|23.1}}<br /><small>(22.2–24.0)</small>
|{{shade|align=center|18.7}}<br /><small>(18.0–19.5)</small>
|{{shade|align=center|4.2}}<br /><small>(4.0–4.5)</small>
|{{shade|align=center|14.3}}<br /><small>(13.9–14.7)</small>
|-
! Male
|{{shade|align=center|26.9}}<br /><small>(23.2–31.0)</small>
|{{shade|align=center|14.0}}<br /><small>(12.2–15.9)</small>
|{{shade|align=center|19.2}}<br /><small>(17.6–20.9)</small>
|{{shade|align=center|26.9}}<br /><small>(25.3–28.5)</small>
|{{shade|align=center|33.4}}<br /><small>(32.0–34.8)</small>
|{{shade|align=center|37.3}}<br /><small>(36.0–38.6)</small>
|{{shade|align=center|30.2}}<br /><small>(29.2–31.3)</small>
|{{shade|align=center|6.8}}<br /><small>(6.5–7.2)</small>
|{{shade|align=center|23.1}}<br /><small>(22.6–23.6)</small>
|-
! Total
|{{shade|align=center|22.2}}<br /><small>(19.2–25.5)</small>
|{{shade|align=center|11.5}}<br /><small>(10.1–13.2)</small>
|{{shade|align=center|15.9}}<br /><small>(14.6–17.3)</small>
|{{shade|align=center|22.2}}<br /><small>(21.0–23.5)</small>
|{{shade|align=center|27.6}}<br /><small>(26.5–28.7)</small>
|{{shade|align=center|30.8}}<br /><small>(29.8–31.8)</small>
|{{shade|align=center|24.9}}<br /><small>(24.1–25.8)</small>
|{{shade|align=center|5.6}}<br /><small>(5.3–5.9)</small>
|{{shade|align=center|19.0}}<br /><small>(18.7–19.44)</small>
|-
!colspan="10| Percent of hospitalized people who die
|-
!
! 0–19
! 20–29
! 30–39
! 40–49
! 50–59
! 60–69
! 70–79
! 80+
! Total
|-
! Female
|{{shade|align=center|0.5}}<br /><small>(0.2–1.1)</small>
|{{shade|align=center|0.9}}<br /><small>(0.5–1.3)</small>
|{{shade|align=center|1.5}}<br /><small>(1.2–1.9)</small>
|{{shade|align=center|2.6}}<br /><small>(2.3–3.0)</small>
|{{shade|align=center|5.2}}<br /><small>(4.8–5.6)</small>
|{{shade|align=center|10.1}}<br /><small>(9.5–10.6)</small>
|{{shade|align=center|16.7}}<br /><small>(16.0–17.4)</small>
|{{shade|align=center|25.2}}<br /><small>(24.4–26.0)</small>
|{{shade|align=center|14.4}}<br /><small>(14.0–14.9)</small>
|-
! Male
|{{shade|align=center|0.7}}<br /><small>(0.3–1.5)</small>
|{{shade|align=center|1.3}}<br /><small>(0.8–1.9)</small>
|{{shade|align=center|2.2}}<br /><small>(1.7–2.7)</small>
|{{shade|align=center|3.8}}<br /><small>(3.4–4.4)</small>
|{{shade|align=center|7.6}}<br /><small>(7.0–8.2)</small>
|{{shade|align=center|14.8}}<br /><small>(14.1–15.6)</small>
|{{shade|align=center|24.6}}<br /><small>(23.7–25.6)</small>
|{{shade|align=center|37.1}}<br /><small>(36.1–38.2)</small>
|{{shade|align=center|21.22}}<br /><small>(20.8–21.7)</small>
|-
! Total
|{{shade|align=center|0.6}}<br /><small>(0.3–1.3)</small>
|{{shade|align=center|1.1}}<br /><small>(0.7–1.6)</small>
|{{shade|align=center|1.9}}<br /><small>(1.5–2.3)</small>
|{{shade|align=center|3.3}}<br /><small>(2.9–3.7)</small>
|{{shade|align=center|6.5}}<br /><small>(6.0–7.0)</small>
|{{shade|align=center|12.6}}<br /><small>(12.0–13.2)</small>
|{{shade|align=center|21.0}}<br /><small>(20.3–21.8)</small>
|{{shade|align=center|31.6}}<br /><small>(30.9–32.4)</small>
|{{shade|align=center|18.1}}<br /><small>(17.8–18.4)</small>
|-
!colspan="10| Percent of infected people who die{{snd}}infection fatality rate (IFR)
|-
!
! 0–19
! 20–29
! 30–39
! 40–49
! 50–59
! 60–69
! 70–79
! 80+
! Total
|-
! Female
|{{shade|align=center|0.001}}<br /><small>(<0.001–0.002)</small>
|{{shade|align=center|0.005}}<br /><small>(0.002–0.009)</small>
|{{shade|align=center|0.02}}<br /><small>(0.01–0.03)</small>
|{{shade|align=center|0.04}}<br /><small>(0.02–0.07)</small>
|{{shade|align=center|0.2}}<br /><small>(0.1–0.3)</small>
|{{shade|align=center|0.6}}<br /><small>(0.4–1.0)</small>
|{{shade|align=center|1.6}}<br /><small>(1.0–2.5)</small>
|{{shade|align=center|5.9}}<br /><small>(3.5–9.2)</small>
|{{shade|align=center|0.5}}<br /><small>(0.3–0.7)</small>
|-
! Male
|{{shade|align=center|0.001}}<br /><small>(<0.001–0.003)</small>
|{{shade|align=center|0.008}}<br /><small>(0.004–0.02)</small>
|{{shade|align=center|0.03}}<br /><small>(0.02–0.05)</small>
|{{shade|align=center|0.07}}<br /><small>(0.04–0.1)</small>
|{{shade|align=center|0.3}}<br /><small>(0.2–0.5)</small>
|{{shade|align=center|1.2}}<br /><small>(0.7–1.9)</small>
|{{shade|align=center|3.3}}<br /><small>(2.0–5.1)</small>
|{{shade|align=center|17.1}}<br /><small>(10.1–26.3)</small>
|{{shade|align=center|0.8}}<br /><small>(0.5–1.3)</small>
|-
! Total
|{{shade|align=center|0.001}}<br /><small>(<0.001–0.002)</small>
|{{shade|align=center|0.007}}<br /><small>(0.003–0.01)</small>
|{{shade|align=center|0.02}}<br /><small>(0.01–0.04)</small>
|{{shade|align=center|0.06}}<br /><small>(0.03–0.09)</small>
|{{shade|align=center|0.2}}<br /><small>(0.1–0.36)</small>
|{{shade|align=center|0.9}}<br /><small>(0.5–1.4)</small>
|{{shade|align=center|2.4}}<br /><small>(1.4–3.7)</small>
|{{shade|align=center|10.1}}<br /><small>(6.0–15.6)</small>
|{{shade|align=center|0.7}}<br /><small>(0.4–1.0)</small>
|-
|colspan=10| Numbers in parentheses are 95% [[Credible interval|credible interval]]s for the estimates.
|}

===Ethnic differences===
In the US, a greater proportion of deaths due to COVID-19 have occurred among African Americans.<ref name="AVD">{{cite journal | vauthors = Dorn AV, Cooney RE, Sabin ML | title = COVID-19 exacerbating inequalities in the US | journal = Lancet | volume = 395 | issue = 10232 | pages = 1243–1244 | date = April 2020 | pmid = 32305087 | pmc = 7162639 | doi = 10.1016/S0140-6736(20)30893-X }}</ref> Structural factors that prevent African Americans from practicing social distancing include their concentration in crowded substandard housing and in "essential" occupations such as public transit and health care. Greater prevalence of lacking health insurance and care and of underlying conditions such as [[Medicine:Diabetes|diabetes]], [[Medicine:Hypertension|hypertension]] and heart disease also increase their risk of death.<ref>{{cite journal | vauthors = Adams ML, Katz DL, Grandpre J | title = Population-Based Estimates of Chronic Conditions Affecting Risk for Complications from Coronavirus Disease, United States | journal = Emerging Infectious Diseases | volume = 26 | issue = 8 | date = April 2020 | pmid = 32324118 | doi = 10.3201/eid2608.200679 | doi-access = free }}</ref> Similar issues affect Native American and Latino communities.<ref name="AVD" /> According to a US health policy non-profit, 34% of American Indian and Alaska Native People (AIAN) non-elderly adults are at risk of serious illness compared to 21% of white non-elderly adults.<ref>{{Cite web|url=https://www.kff.org/coronavirus-covid-19/issue-brief/covid-19-presents-significant-risks-for-american-indian-and-alaska-native-people/|title=COVID-19 Presents Significant Risks for American Indian and Alaska Native People|date=14 May 2020}}</ref> The source attributes it to disproportionately high rates of many health conditions that may put them at higher risk as well as living conditions like lack of access to clean water.<ref>{{Cite web|title=COVID-19 Presents Significant Risks for American Indian and Alaska Native People|url=https://www.kff.org/coronavirus-covid-19/issue-brief/covid-19-presents-significant-risks-for-american-indian-and-alaska-native-people/|last=|first=|date=14 May 2020|website=|url-status=live|archive-url=|archive-date=|access-date=}}</ref> Leaders have called for efforts to research and address the disparities.<ref>{{cite journal | vauthors = Laurencin CT, McClinton A | title = The COVID-19 Pandemic: a Call to Action to Identify and Address Racial and Ethnic Disparities | journal = Journal of Racial and Ethnic Health Disparities | date = April 2020 | volume = 7 | issue = 3 | pages = 398–402 | pmid = 32306369 | doi = 10.1007/s40615-020-00756-0 | pmc = 7166096 }}</ref>

In the U.K., a greater proportion of deaths due to COVID-19 have occurred in those of a Black, Asian, and other ethnic minority background.<ref>{{Cite web|date=9 June 2020|title=How coronavirus deaths in the UK compare by race and ethnicity|url=https://www.independent.co.uk/news/uk/home-news/coronavirus-death-toll-uk-race-white-black-asian-bame-ethnicity-cases-a9557076.html|access-date=10 June 2020|website=The Independent}}</ref><ref>{{Cite web|title=Emerging findings on the impact of COVID-19 on black and minority ethnic people|url=https://www.health.org.uk/news-and-comment/charts-and-infographics/emerging-findings-on-the-impact-of-covid-19-on-black-and-min|access-date=10 June 2020|website=The Health Foundation}}</ref><ref>{{Cite news|last1=Butcher|first1=Benjamin|last2=Massey|first2=Joel|date=9 June 2020|title=Why are more BAME people dying from coronavirus?|work=BBC News Online|url=https://www.bbc.com/news/uk-52219070|access-date=10 June 2020}}</ref> Several factors such as poverty, poor nutrition and living in overcrowded properties, may have caused this.{{citation needed|date=June 2020}}

==Society and culture==
===Name===
 During the initial outbreak in Wuhan, China, the virus and disease were commonly referred to as "coronavirus" and "Wuhan coronavirus",<ref>{{cite web|url=https://www.npr.org/sections/health-shots/2020/01/24/799208865/a-second-u-s-case-of-wuhan-coronavirus-is-confirmed|title=2nd U.S. Case Of Wuhan Coronavirus Confirmed|website=NPR.org|access-date=4 April 2020}}</ref><ref>{{cite news|last=McNeil Jr |first = Donald G. |  name-list-format = vanc |url=https://www.nytimes.com/2020/02/02/health/coronavirus-pandemic-china.html|title=Wuhan Coronavirus Looks Increasingly Like a Pandemic, Experts Say|date=2 February 2020|work={{wipe|The New York Times}}|access-date=4 April 2020|issn=0362-4331 }}</ref><ref>{{cite news|url=https://www.cnn.com/2020/02/05/asia/wuhan-coronavirus-update-death-toll-spike-intl-hnk/index.html|title=Wuhan coronavirus deaths spike again as outbreak shows no signs of slowing|last=Griffiths|first=James| name-list-format = vanc |website=CNN|access-date=4 April 2020}}</ref> with the disease sometimes called "Wuhan pneumonia".<ref>{{cite journal | vauthors = Jiang S, Xia S, Ying T, Lu L | title = A novel coronavirus (2019-nCoV) causing pneumonia-associated respiratory syndrome | journal = Cellular & Molecular Immunology | volume = 17 | issue = 5 | pages = 554 | date = May 2020 | pmid = 32024976 | doi = 10.1038/s41423-020-0372-4 | pmc = 7091741 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Chan JF, Yuan S, Kok KH, To KK, Chu H, Yang J, Xing F, Liu J, Yip CC, Poon RW, Tsoi HW, Lo SK, Chan KH, Poon VK, Chan WM, Ip JD, Cai JP, Cheng VC, Chen H, Hui CK, Yuen KY | display-authors = 6 | title = A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: a study of a family cluster | journal = Lancet | volume = 395 | issue = 10223 | pages = 514–523 | date = February 2020 | pmid = 31986261 | pmc = 7159286 | doi = 10.1016/S0140-6736(20)30154-9 | doi-access = free }}</ref> In the past, many diseases have been named after geographical locations, such as the Spanish flu,<ref>{{cite journal |last1=Shablovsky |first1=Suzanne |s2cid=44116811 | name-list-format = vanc |title=The legacy of the Spanish flu |journal=Science |date=22 September 2017 |volume=357 |issue=6357 |pages=1245 |doi=10.1126/science.aao4093 |bibcode=2017Sci...357.1245S |url=https://science.sciencemag.org/content/357/6357/1245 |issn=0036-8075}}</ref> Middle East Respiratory Syndrome, and [[Medicine:Zika virus|Zika virus]].<ref name="Nature Stop">{{cite news |title=Stop the coronavirus stigma now |url=https://www.nature.com/articles/d41586-020-01009-0 |access-date=16 April 2020 |work=Nature |date=7 April 2020 |pages=165 |doi=10.1038/d41586-020-01009-0}}</ref>

In January 2020, the World Health Organisation recommended 2019-nCov<ref>{{cite web|url=https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200121-sitrep-1-2019-ncov.pdf|title=Novel Coronavirus (2019-nCoV) SITUATION REPORT—1 | date=21 January 2020|website=[[Organization:World Health Organization|World Health Organization]] (WHO) |url-status=live|archive-url=|archive-date=|access-date=}}</ref> and 2019-nCoV acute respiratory disease<ref>{{cite web|url=https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200130-sitrep-10-ncov.pdf|title=Novel Coronavirus(2019-nCoV) Situation Report—10 | date=30 January 2020|website=[[Organization:World Health Organization|World Health Organization]] (WHO) |url-status=live|archive-url=|archive-date=|access-date=}}</ref> as interim names for the virus and disease per 2015 guidance and international guidelines against using geographical locations (e.g. Wuhan, China), animal species or groups of people in disease and virus names to prevent [[Social:Social stigma|social stigma]].<ref>{{cite news |title=Novel coronavirus named 'Covid-19': WHO |url=https://www.todayonline.com/world/wuhan-novel-coronavirus-named-covid-19-who |access-date=11 February 2020 |publisher=TODAYonline |name-list-format=vanc |archive-url=https://archive.today/20200321085608/https://www.todayonline.com/world/wuhan-novel-coronavirus-named-covid-19-who |archive-date=21 March 2020 |url-status=live }}</ref><ref name="veconomist">{{cite news|author= |title= The coronavirus spreads racism against—and among—ethnic Chinese|url= https://www.economist.com/china/2020/02/17/the-coronavirus-spreads-racism-against-and-among-ethnic-chinese|work= [[Finance:The Economist|The Economist]]|date= 17 February 2020|access-date= 17 February 2020|archive-url= https://web.archive.org/web/20200217223902/https://www.economist.com/china/2020/02/17/the-coronavirus-spreads-racism-against-and-among-ethnic-chinese|archive-date= 17 February 2020|url-status= live| name-list-format = vanc}}</ref><ref>{{cite web|url=https://apps.who.int/iris/bitstream/handle/10665/163636/WHO_HSE_FOS_15.1_eng.pdf|title=World Health Organization Best Practices for the Naming of New Human Infectious Diseases | date=May 2015|website=[[Organization:World Health Organization|World Health Organization]] (WHO) |url-status=live|archive-url=|archive-date=|access-date=}}</ref>

The official names COVID‑19 and SARS-CoV-2 were issued by the WHO on 11 February 2020.<ref name="WHO-naming">{{cite web|url=https://www.who.int/emergencies/diseases/novel-coronavirus-2019/technical-guidance/naming-the-coronavirus-disease-(covid-2019)-and-the-virus-that-causes-it|title=Naming the coronavirus disease (COVID-19) and the virus that causes it|website=[[Organization:World Health Organization|World Health Organization]] (WHO)|access-date=13 March 2020|archive-url=https://web.archive.org/web/20200228035651/https://www.who.int/emergencies/diseases/novel-coronavirus-2019/technical-guidance/naming-the-coronavirus-disease-(covid-2019)-and-the-virus-that-causes-it|archive-date=28 February 2020|url-status=live}}</ref> WHO chief Tedros Adhanom Ghebreyesus explained: CO for ''corona'', VI for ''virus'', D{{nbsp}}for ''disease'' and 19 for when the outbreak was first identified (31 December 20''19'').<ref>{{cite report |title=Coronavirus disease 2019 (COVID-19) in the EU/EEA and the UK—eighth update |url=https://www.ecdc.europa.eu/sites/default/files/documents/covid-19-rapid-risk-assessment-coronavirus-disease-2019-eighth-update-8-april-2020.pdf |access-date=19 April 2020 |publisher=ecdc |archive-url=https://web.archive.org/web/20200314223709/https://www.ecdc.europa.eu/sites/default/files/documents/RRA-sixth-update-Outbreak-of-novel-coronavirus-disease-2019-COVID-19.pdf |archive-date=14 March 2020 |url-status=live }}</ref> The WHO additionally uses "the COVID‑19 virus" and "the virus responsible for COVID‑19" in public communications.<ref name="WHO-naming" />

===Misinformation===

{{main|Social:Misinformation related to the COVID-19 pandemic}}

After the initial outbreak of COVID‑19, misinformation and [[Social:Disinformation|disinformation]] regarding the origin, scale, prevention, treatment, and other aspects of the disease rapidly spread online.<ref name="bbc_misinfo">{{cite news |url=https://www.bbc.com/news/blogs-trending-51271037 |title=China coronavirus: Misinformation spreads online about origin and scale |date=30 January 2020 |publisher=BBC News Online |access-date=10 February 2020 |archive-url= https://web.archive.org/web/20200204163412/https://www.bbc.com/news/blogs-trending-51271037 |archive-date=4 February 2020 |url-status=live}}</ref><ref name="GUAR">{{cite newspaper | url=https://www.theguardian.com/world/2020/jan/31/bat-soup-dodgy-cures-and-diseasology-the-spread-of-coronavirus-bunkum | title=Bat soup, dodgy cures and 'diseasology': the spread of coronavirus misinformation | date=31 January 2020 | access-date=3 February 2020 | first=Josh | last=Taylor | name-list-format = vanc | newspaper={{wipe|The Guardian}} | archive-url=https://web.archive.org/web/20200202141231/https://www.theguardian.com/world/2020/jan/31/bat-soup-dodgy-cures-and-diseasology-the-spread-of-coronavirus-bunkum | archive-date=2 February 2020 | url-status=live }}</ref><ref name="RunningList">{{cite web |url=https://www.buzzfeednews.com/article/janelytvynenko/coronavirus-disinformation-spread |title=Here's A Running List Of Disinformation Spreading About The Coronavirus |website=Buzzfeed News |access-date=8 February 2020 |archive-url=https://web.archive.org/web/20200206212717/https://www.buzzfeednews.com/article/janelytvynenko/coronavirus-disinformation-spread |archive-date=6 February 2020 |url-status=live }}</ref>

===Other health issues===


The pandemic has had many impacts on global health beyond those caused by the COVID-19 disease itself. It has led to a reduction in hospital visits for other reasons. There have been 38% fewer hospital visits for heart attack symptoms in the United States and 40% fewer in Spain.<ref>{{cite journal | vauthors = Garcia S, Albaghdadi MS, Meraj PM, Schmidt C, Garberich R, Jaffer FA, Dixon S, Rade JJ, Tannenbaum M, Chambers J, Huang PP, Henry TD | display-authors = 6 | title = Reduction in ST-Segment Elevation Cardiac Catheterization Laboratory Activations in the United States during COVID-19 Pandemic | journal = Journal of the American College of Cardiology | date = April 2020 | pmid = 32283124 | pmc = 7151384 | doi = 10.1016/j.jacc.2020.04.011 }}</ref> The head of cardiology at the [[Organization:University of Arizona|University of Arizona]] said, "My worry is some of these people are dying at home because they're too scared to go to the hospital."<ref name="Stat News, with serious heart symptoms away, April 23">[https://www.statnews.com/2020/04/23/coronavirus-phobia-keeping-heart-patients-away-from-er/ 'Where are all our patients?': Covid phobia is keeping people with serious heart symptoms away from ERs], ''Stat News'', Usha Lee McFarling, 23 April 2020.</ref> There is also concern that people with [[Medicine:Stroke|stroke]]s and [[Medicine:Appendicitis|appendicitis]] are not seeking timely treatment.<ref name="Stat News, with serious heart symptoms away, April 23"/> [[Finance:Shortages related to the COVID-19 pandemic|Shortages]] of medical supplies have impacted people with various conditions.<ref name="Atlantic Shortages">{{cite news |last1=Faust |first1=Jeremy Samuel |title=Medication Shortages Are the Next Crisis |url=https://www.theatlantic.com/ideas/archive/2020/04/medication-shortages-are-next-crisis/610798/ |accessdate=17 May 2020 |work=The Atlantic |date=28 April 2020}}</ref> In several countries there has been a marked reduction of spread of [[Medicine:Sexually transmitted infection|sexually transmitted infection]]s, including [[Biology:HIV|HIV]], attributable to COVID-19 quarantines and social distancing measures.<ref>{{Cite web|title=Sexually transmitted infections surveillance reports – Reports|url=https://www.health.nsw.gov.au/Infectious/reports/Pages/STI-reports.aspx|website=www.health.nsw.gov.au|access-date=9 May 2020}}</ref><ref>{{Cite web|title=U.K. Lockdown Has 'Broken HIV Chain' With Huge Reduction In New STI Cases|url=https://www.forbes.com/sites/jamiewareham/2020/05/01/uk-lockdown-has-broken-hiv-chain-with-huge-reduction-in-new-sti-cases/|last=Wareham|first=Jamie|website=Forbes|access-date=9 May 2020}}</ref> Similarly, in some places, rates of transmission of [[Medicine:Influenza|influenza]] and other respiratory viruses significantly decreased during the pandemic.<ref>{{Cite journal|last=Cowling|first=Benjamin J.|last2=Ali|first2=Sheikh Taslim|last3=Ng|first3=Tiffany W. Y.|last4=Tsang|first4=Tim K.|last5=Li|first5=Julian C. M.|last6=Fong|first6=Min Whui|last7=Liao|first7=Qiuyan|last8=Kwan|first8=Mike YW|last9=Lee|first9=So Lun|last10=Chiu|first10=Susan S.|last11=Wu|first11=Joseph T.|date=1 May 2020|title=Impact assessment of non-pharmaceutical interventions against coronavirus disease 2019 and influenza in Hong Kong: an observational study|url=https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(20)30090-6/abstract|journal=The Lancet Public Health|volume=5|issue=5|pages=e279–e288|doi=10.1016/S2468-2667(20)30090-6|issn=2468-2667|pmid=32311320|pmc=7164922}}</ref><ref>{{Cite web|title=Australia sees huge decrease in flu cases due to coronavirus measures|url=https://www.newscientist.com/article/2242113-australia-sees-huge-decrease-in-flu-cases-due-to-coronavirus-measures/|last=Klein|first=Alice|website=New Scientist|access-date=9 May 2020}}</ref><ref>{{Cite web|title=Weekly U.S. Influenza Surveillance Report (FluView)|url=https://www.cdc.gov/flu/weekly/index.htm|date=8 May 2020|website=U.S. Centers for Disease Control and Prevention (CDC)|access-date=9 May 2020}}</ref> The pandemic has also negatively impacted mental health globally, including increased [[Social:Loneliness|loneliness]] resulting from social distancing.<ref name="Brooks26Feb2020">{{Cite journal |author-last1=Brooks |author-first1=Samantha K. |author-last2=Webster |author-first2=Rebecca K. |author-last3=Smith |author-first3=Louise E. |author-last4=Woodland |author-first4=Lisa |author-last5=Wessely |author-first5=Simon |author-last6=Greenberg |author-first6=Neil |author-link6=Neil Greenberg |author-last7=Rubin |author-first7=Gideon James |date=14 March 2020 |title=The psychological impact of quarantine and how to reduce it: rapid review of the evidence |url=https://www.thelancet.com/action/showPdf?pii=S0140-6736%2820%2930460-8 |journal=The Lancet |language=en |volume=395 |issue=10227 |pages=912–920 |doi=10.1016/S0140-6736(20)30460-8 |issn=0140-6736 |pmid=32112714 |pmc=7158942 |access-date=20 March 2020 |archive-url=https://web.archive.org/web/20200313220120/https://www.thelancet.com/action/showPdf?pii=S0140-6736%2820%2930460-8 |archive-date=13 March 2020 |url-status=live }}</ref>

==Other animals==

Humans appear to be capable of spreading the virus to some other animals. A domestic cat in Liège, Belgium, tested positive after it started showing symptoms (diarrhoea, vomiting, shortness of breath) a week later than its owner, who was also positive.<ref>{{cite web|url=https://www.brusselstimes.com/all-news/belgium-all-news/103003/coronavirus-belgian-woman-infected-her-cat/ |title=Coronavirus: Belgian cat infected by owner |publisher=Brusselstimes.com |date=27 March 2020 |access-date=12 April 2020}}</ref> Tigers and lions at the Bronx Zoo in New York, United States, tested positive for the virus and showed symptoms of COVID‑19, including a dry cough and loss of appetite.<ref>{{cite news |last=Goldstein |first=Joseph | name-list-format = vanc |title=Bronx Zoo Tiger Is Sick With the Coronavirus |url=https://www.nytimes.com/2020/04/06/nyregion/bronx-zoo-tiger-coronavirus.html |website={{wipe|The New York Times}} |date=6 April 2020 |access-date=9 April 2020 }}</ref> [[Biology:Mink|Mink]]s at two farms in the Netherlands also tested positive for COVID-19.<ref>{{cite web|url=https://www.foxnews.com/world/mink-netherlands-coronavirus-farm |title=Coronavirus hits Netherlands farm animals as minks test positive for virus |publisher=Fox News |date= 26 April 2020|access-date=27 April 2020}}</ref>

A study on domesticated animals inoculated with the virus found that cats and [[Biology:Ferret|ferret]]s appear to be "highly susceptible" to the disease, while dogs appear to be less susceptible, with lower levels of viral replication. The study failed to find evidence of viral replication in [[Biology:Domestic pig|pigs]], ducks, and [[Biology:Chicken|chicken]]s.<ref>{{cite journal | vauthors = Shi J, Wen Z, Zhong G, Yang H, Wang C, Huang B, Liu R, He X, Shuai L, Sun Z, Zhao Y, Liu P, Liang L, Cui P, Wang J, Zhang X, Guan Y, Tan W, Wu G, Chen H, Bu Z | display-authors = 6 | title = Susceptibility of ferrets, cats, dogs, and other domesticated animals to SARS-coronavirus 2 | journal = Science | pages = 1016–1020 | date = April 2020 | volume = 368 | issue = 6494 | pmid = 32269068 | pmc = 7164390 | doi = 10.1126/science.abb7015 | doi-access = free }}</ref>

In March 2020, researchers from the University of Hong Kong have shown that Syrian hamsters could be a model organism for COVID-19 research.<ref>{{cite journal |vauthors = Chan JF, Zhang AJ, Yuan S, Poon VK, Chan CC, Lee AC, Chan WM, Fan Z, Tsoi HW, Wen L, Liang R, Cao J, Chen Y, Tang K, Luo C, Cai JP, Kok KH, Chu H, Chan KH, Sridhar S, Chen Z, Chen H, To KK, Yuen KY | display-authors = 3 |title = Simulation of the clinical and pathological manifestations of Coronavirus Disease 2019 (COVID-19) in golden Syrian hamster model: implications for disease pathogenesis and transmissibility |journal=Clinical Infectious Diseases |date=March 2020 |issn= 1058-4838 |doi=10.1093/cid/ciaa325 | pmid = 32215622 | pmc = 7184405 |url=https://academic.oup.com/cid/advance-article-pdf/doi/10.1093/cid/ciaa325/32967819/ciaa325.pdf }}</ref>

==Research==

{{main|Biology:COVID-19 drug development}}

No medication or vaccine is approved with the specific indication to treat the disease.<ref name="LiDeClerq">{{cite journal | vauthors = Li G, De Clercq E | title = Therapeutic options for the 2019 novel coronavirus (2019-nCoV) | journal = Nature Reviews. Drug Discovery | volume = 19 | issue = 3 | pages = 149–150 | date = March 2020 | pmid = 32127666 | doi = 10.1038/d41573-020-00016-0 | doi-access = free }}</ref> International research on vaccines and medicines in COVID‑19 is underway by government organisations, academic groups, and industry researchers.<ref name="dhama">{{cite journal | vauthors = Dhama K, Sharun K, Tiwari R, Dadar M, Malik YS, Singh KP, Chaicumpa W | title = COVID-19, an emerging coronavirus infection: advances and prospects in designing and developing vaccines, immunotherapeutics, and therapeutics | journal = Human Vaccines & Immunotherapeutics | pages = 1232–1238 | date = March 2020 | volume = 16 | issue = 6 | pmid = 32186952 | pmc = 7103671 | doi = 10.1080/21645515.2020.1735227 | doi-access = free }}</ref><ref name="zhang2020">{{cite journal | vauthors = Zhang L, Liu Y | title = Potential interventions for novel coronavirus in China: A systematic review | journal = Journal of Medical Virology | volume = 92 | issue = 5 | pages = 479–490 | date = May 2020 | pmid = 32052466 | pmc = 7166986 | doi = 10.1002/jmv.25707 }}</ref> In March, the World Health Organisation initiated the "Solidarity Trial" to assess the treatment effects of four existing antiviral compounds with the most promise of efficacy.<ref name="kai">{{cite journal |last1=Kupferschmidt |first1=Kai |last2=Cohen |first2=Jon| name-list-format = vanc | title=WHO launches global megatrial of the four most promising coronavirus treatments |journal=Science Magazine | date=22 March 2020 | url=https://www.sciencemag.org/news/2020/03/who-launches-global-megatrial-four-most-promising-coronavirus-treatments | access-date=27 March 2020|doi=10.1126/science.abb8497}}</ref> The World Health Organization suspended hydroxychloroquine from its global drug trials for COVID-19 treatments on 26 May 2020 due to safety concerns. It had previously enrolled 3,500 patients from 17 countries in the Solidarity Trial.<ref name=20200526nytimes>{{cite web| url=https://www.nytimes.com/2020/05/26/world/coronavirus-news.html| title=Citing safety concerns, the W.H.O. paused tests of a drug Trump said he had taken.| date=26 May 2020| work=The New York Times}}</ref> France, Italy and Belgium also banned the use of hydroxychloroquine as a COVID-19 treatment.<ref>{{cite web| url=https://www.cbsnews.com/news/france-bans-use-of-hydroxychloroquine-drug-touted-by-trump-to-treat-coronavirus/| title=France bans use of hydroxychloroquine, drug touted by Trump, in coronavirus patients| date=27 May 2020| publisher=CBS News}}</ref>

There has been a great deal of COVID-19 research, involving accelerated research processes and publishing shortcuts to meet the global demand. To minimise the harm from [[Social:Misinformation related to the COVID-19 pandemic|misinformation]], medical professionals and the public are advised to expect rapid changes to available information, and to be attentive to [[Retractions in academic publishing|retractions]] and other updates.<ref>{{cite web|url=http://www.covidliterature.ca/|title=Navigating the COVID-19 Evidence Landscape|last1=Bradley-Ridout|first1=Glyneva|last2=Fuller|first2=Kaitlin |last3=Gray|first3=Mikaela|last4=Nekolaichuk|first4=Erica | name-list-format = vanc |date=9 April 2020|website=|publisher=University of Toronto Libraries—Gerstein Science Information Centre|url-status=live|archive-url=|archive-date=|access-date=}}</ref>

===Vaccine===

{{main|Medicine:COVID-19 vaccine}}

There is no available vaccine, but various agencies are actively developing vaccine candidates. Previous work on SARS-CoV is being used because both SARS-CoV and SARS-CoV-2 use the ACE2 receptor to enter human cells.<ref>{{cite book | vauthors=Cascella M, Rajnik M, Cuomo A, Dulebohn SC, Di Napoli R | chapter=Features, Evaluation and Treatment Coronavirus (COVID-19) | title=StatPearls [Internet] | chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK554776/ |date=March 2020 | publisher=StatPearls |pmid= 32150360 | id=Bookshelf ID: NBK554776 }}</ref> Six vaccination strategies are being investigated. Four of these, as of early July 2020, are being tested in clinical trials.<ref name="auto1">WHO team. "Draft Landscape of COVID-19 Candidate Vaccines." World Health Organization, World Health Organization, 29 June 2020, www.who.int/publications/m/item/draft-landscape-of-covid-19-candidate-vaccines.</ref> First, researchers aim to build a whole virus vaccine. The use of such [[Medicine:Inactivated vaccine|inactive]] virus aims to elicit a prompt [[Biology:Immune response|immune response]] of the human body to a new infection with COVID‑19. A second strategy, subunit vaccines, aims to create a vaccine that sensitises the immune system to certain subunits of the virus. In the case of SARS-CoV-2, such research focuses on the S-spike protein that helps the virus intrude the ACE2 enzyme receptor. A third strategy is that of the nucleic acid vaccines ([[Biology:DNA vaccination|DNA]] or RNA vaccines, a novel technique for creating a vaccination). Fourthly, scientists are attempting to use viral vectors to deliver the SARS-CoV-2 antigen gene into the cell.<ref name="auto2">Vaccitech. "Technology." Vaccitech, 21 May 2020, www.vaccitech.co.uk/technology.</ref> These can be replicating or non-replicating. As of early July 2020, only non-replicating viral vectors are in clinical trials. Viral vectors in clinical trials include Chimpanzee Adenovirus 63,<ref name="auto2"/> Adenovirus type-5,<ref name="auto1"/> and Adenovirus type-26.<ref>"An Open Study of the Safety, Tolerability and Immunogenicity of the Drug 'Gam-COVID-Vac' Vaccine Against COVID-19 – Full Text View." Full Text View – ClinicalTrials.gov, 22 June 2020, clinicaltrials.gov/ct2/show/NCT04436471?term=vaccine.</ref> Scientists are also working to develop an attenuated COVID-19 vaccine and a COVID-19 vaccine using [[Biology:Virus-like particle|virus-like particle]]s, but these are still in preclinical research.<ref name="auto1"/> Experimental vaccines from any of these strategies would have to be tested for safety and efficacy.<ref name="Chen Strych Hotez Bottazzi p.">{{cite journal | vauthors = Chen WH, Strych U, Hotez PJ, Bottazzi ME | title = The SARS-CoV-2 Vaccine Pipeline: an Overview | journal = Current Tropical Medicine Reports | pages = 61–64 | date = March 2020 | volume = 7 | issue = 2 | pmid = 32219057 | pmc = 7094941 | doi = 10.1007/s40475-020-00201-6 | doi-access = free }}</ref>

[[Biology:Antibody-dependent enhancement|Antibody-dependent enhancement]] has been suggested as a potential challenge for vaccine development for SARS-COV-2, but this is controversial.<ref name="PNAS2020">{{cite journal | vauthors = Peeples L | title = News Feature: Avoiding pitfalls in the pursuit of a COVID-19 vaccine | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 117 | issue = 15 | pages = 8218–8221 | date = April 2020 | pmid = 32229574 | pmc = 7165470 | doi = 10.1073/pnas.2005456117 | publisher = Proceedings of the National Academy of Sciences }}</ref>

===Medications===


At least 29 phase II–IV efficacy trials in COVID‑19 were concluded in March 2020, or scheduled to provide results in April from hospitals in China.<ref name="milken">{{cite web |title=COVID-19 treatment and vaccine tracker |url=https://milkeninstitute.org/sites/default/files/2020-04/Covid19%20Tracker%20NEW4-21-20-2.pdf |publisher=Milken Institute |access-date=21 April 2020 |date=21 April 2020 |lay-url=https://milkeninstitute.org/covid-19-tracker }}</ref><ref name="koch">{{cite web | first1 = Selina | last1 = Koch | first2 = Winnie | last2 = Pong | name-list-format = vanc |title=First up for COVID-19: nearly 30 clinical readouts before end of April |url=https://www.biocentury.com/article/304658 |publisher=BioCentury Inc. |access-date=1 April 2020 |date=13 March 2020}}</ref> There are more than 300 active clinical trials underway as of April 2020.<ref name="Sanders20202" /> Seven trials were evaluating already approved treatments, including four studies on [[Chemistry:Hydroxychloroquine|hydroxychloroquine]] or [[Chemistry:Chloroquine|chloroquine]].<ref name=koch/> Repurposed [[Biology:Antiviral drug|antiviral drug]]s make up most of the research, with nine phase III trials on remdesivir across several countries due to report by the end of April.<ref name=milken/><ref name=koch/> Other candidates in trials include vasodilators, [[Biology:Corticosteroid|corticosteroid]]s, [[Medicine:Immunotherapy|immune therapies]], [[Chemistry:Lipoic acid|lipoic acid]], [[Chemistry:Bevacizumab|bevacizumab]], and [[Biology:Recombinant DNA|recombinant]] [[Biology:Angiotensin-converting enzyme 2|angiotensin-converting enzyme 2]].<ref name=koch/>

The COVID‑19 Clinical Research Coalition has goals to 1) facilitate rapid reviews of clinical trial proposals by [[Social:Ethics committee|ethics committee]]s and national regulatory agencies, 2) fast-track approvals for the candidate therapeutic compounds, 3) ensure standardised and rapid analysis of emerging efficacy and safety data and 4) facilitate sharing of clinical trial outcomes before publication.<ref name="coalition">{{cite journal | author = COVID-19 Clinical Research Coalition | title = Global coalition to accelerate COVID-19 clinical research in resource-limited settings | journal = Lancet | volume = 395 | issue = 10233 | pages = 1322–1325 | date = April 2020 | pmid = 32247324 | doi = 10.1016/s0140-6736(20)30798-4 | pmc = 7270833 | url = https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30798-4/fulltext#articleInformation | doi-access = free }}</ref><ref name="maguire">{{cite journal | vauthors = Maguire BJ, Guérin PJ | title = A living systematic review protocol for COVID-19 clinical trial registrations | journal = Wellcome Open Research | volume = 5 | pages = 60 | date = 2 April 2020 | pmid = 32292826 | pmc = 7141164 | doi = 10.12688/wellcomeopenres.15821.1 }}</ref>

Several existing medications are being evaluated for the treatment of COVID‑19,<ref name="LiDeClerq" /> including [[Biology:Remdesivir|remdesivir]], [[Chemistry:Chloroquine|chloroquine]], [[Chemistry:Hydroxychloroquine|hydroxychloroquine]], lopinavir/ritonavir, and lopinavir/ritonavir combined with interferon beta.<ref name=kai/><ref>{{cite web|url=https://news.un.org/en/story/2020/03/1059722|title=UN health chief announces global 'solidarity trial' to jumpstart search for COVID-19 treatment|date=18 March 2020|website=UN News|access-date=23 March 2020|archive-url=https://web.archive.org/web/20200323101633/https://news.un.org/en/story/2020/03/1059722|archive-date=23 March 2020|url-status=live}}</ref> There is tentative evidence for efficacy by remdesivir, and on 1 May 2020, the United States [[Organization:Food and Drug Administration|Food and Drug Administration]] (FDA) gave the drug an emergency use authorization for people hospitalized with severe COVID‑19.<ref>{{Cite press release |date=4 May 2020|title=Coronavirus (COVI D-19) Update: FDA Issues Emergency Use Authorization for Potential COVID-19 Treatment|work=U.S. [[Organization:Food and Drug Administration|Food and Drug Administration]] (FDA)|url=https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-issues-emergency-use-authorization-potential-covid-19-treatment|access-date=8 June 2020}}</ref>  Phase III clinical trials for several drugs are underway in several countries, including the US, China, and Italy.<ref name="LiDeClerq" /><ref name=milken/><ref>{{cite journal |last1=Beeching |first1=Nicholas J. |last2=Fletcher |first2=Tom E. |last3=Fowler |first3=Robert |name-list-format=vanc |date=2020 |title=BMJ Best Practices: COVID-19 |url= https://bestpractice.bmj.com/topics/en-gb/3000168/pdf/3000168/COVID-19.pdf |url-status=live |journal=BMJ |access-date=11 March 2020 |archive-url=https://web.archive.org/web/20200222170544/https://bestpractice.bmj.com/topics/en-gb/3000168/pdf/3000168/COVID-19.pdf |archive-date=22 February 2020 }}</ref>

There are mixed results as of 3 April 2020 as to the effectiveness of hydroxychloroquine as a treatment for COVID‑19, with some studies showing little or no improvement.<ref>{{cite news |last1=Seley-Radtke |first1=Katherine | name-list-format = vanc |title=Professor of Chemistry and Biochemistry and President-Elect of the International Society for Antiviral Research, University of Maryland, Baltimore County |url=https://theconversation.com/a-small-trial-finds-that-hydroxychloroquine-is-not-effective-for-treating-coronavirus-135484 |access-date=5 April 2020 |work=The Conversation |date=3 April 2020}}</ref><ref>{{cite journal | vauthors = Molina JM, Delaugerre C, Le Goff J, Mela-Lima B, Ponscarme D, Goldwirt L, de Castro N | title = No evidence of rapid antiviral clearance or clinical benefit with the combination of hydroxychloroquine and azithromycin in patients with severe COVID-19 infection | language = fr | journal = Medecine et Maladies Infectieuses | volume = 50 | issue = 4 | pages = 384 | date = June 2020 | pmid = 32240719 | pmc = 7195369 | doi = 10.1016/j.medmal.2020.03.006 }}</ref> One study has shown an association between hydroxychloroquine or chloroquine use with higher death rates along with other side effects.<ref>{{Cite web | first1 = Ariana Eunjung | last1 = Cha | first2 = Laurie | last2 = McGinley | name-list-format = vanc |title=Antimalarial drug touted by President Trump is linked to increased risk of death in coronavirus patients, study says |url= https://www.washingtonpost.com/health/2020/05/22/hydroxychloroquine-coronavirus-study/ |website=Washington Post|access-date=27 May 2020 }}</ref><ref>{{cite journal | vauthors = Mehra MR, Desai SS, Ruschitzka F, Patel AN | title = Hydroxychloroquine or chloroquine with or without a macrolide for treatment of COVID-19: a multinational registry analysis | language = English | journal = Lancet | volume = 0 | date = May 2020 | pmid = 32450107 | pmc = 7255293 | doi = 10.1016/S0140-6736(20)31180-6 | url = https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)31180-6/abstract | doi-access = free }}</ref> A retraction of this study by its authors was published by ''The Lancet'' on 4 June 2020.<ref>{{Cite journal | vauthors = Mehra MR, Desai SS, Ruschitzka F, Patel AN |date=4 June 2020|title=Retraction: "Hydroxychloroquine or chloroquine with or without a macrolide for treatment of COVID-19: a multinational registry analysis"|url=https://www.thelancet.com/lancet/article/s0140673620313246|journal=Lancet|volume=395|issue=10240|page=1820glish|doi=10.1016/S0140-6736(20)31324-6|pmid=32511943|pmc=7274621|doi-access=free}}</ref> The studies of chloroquine and hydroxychloroquine with or without [[Chemistry:Azithromycin|azithromycin]] have major limitations that have prevented the medical community from embracing these therapies without further study.<ref name="Sanders20202" /> On 15 June 2020, the FDA updated the fact sheets for the emergency use authorization of remdesivir to warn that using chloroquine or hydroxychloroquine with remdesivir may reduce the antiviral activity of remdesivir.<ref>{{cite press release | title=Coronavirus (COVID-19) Update: FDA Warns of Newly Discovered Potential Drug Interaction That May Reduce Effectiveness of a COVID-19 Treatment Authorized for Emergency Use | website=U.S. [[Organization:Food and Drug Administration|Food and Drug Administration]] (FDA) | date=15 June 2020 | url=https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-warns-newly-discovered-potential-drug-interaction-may-reduce | access-date=15 June 2020}} {{PD-notice}}</ref>

In June, initial results from a [[Medicine:RECOVERY Trial|randomised trial]] in the United Kingdom showed that [[Biology:Dexamethasone|dexamethasone]] reduced mortality by one third for patients who are critically ill on ventilators and one fifth for those receiving supplemental oxygen.<ref>{{cite news |last1=Boseley |first1=Sarah |title=Recovery trial for Covid-19 treatments: what we know so far |url=https://www.theguardian.com/world/2020/jun/16/recovery-trial-for-covid-19-treatments-what-we-know-so-far |accessdate=21 June 2020 |work={{wipe|The Guardian}} |date=16 June 202}}</ref> Because this is a well tested and widely available treatment this was welcomed by the WHO that is in the process of updating treatment guidelines to include dexamethasone or other steroids.<ref>{{cite web |title=WHO welcomes preliminary results about dexamethasone use in treating critically ill COVID-19 patients |url=https://www.who.int/news-room/detail/16-06-2020-who-welcomes-preliminary-results-about-dexamethasone-use-in-treating-critically-ill-covid-19-patients |website=World Health Organisation |accessdate=21 June 2020 |date=16 June 2020}}</ref><ref>{{Cite web|title=Q&A: Dexamethasone and COVID-19|url=https://www.who.int/news-room/q-a-detail/q-a-dexamethasone-and-covid-19|access-date=2020-07-12|website=www.who.int|language=en}}</ref> Based on those preliminary results, dexamethasone treatment has been recommended by the [[Organization:National Institutes of Health|National Institutes of Health]] for patients with COVID-19 who are mechanically ventilated or who require supplemental oxygen but not in patients with COVID-19 who do not require supplemental oxygen.<ref>{{Cite web|last=|first=|date=|title=Dexamethasone {{!}} Coronavirus Disease COVID-19|url=https://www.covid19treatmentguidelines.nih.gov/dexamethasone/|url-status=live|archive-url=|archive-date=|access-date=2020-07-12|website=COVID-19 Treatment Guidelines|publisher=National Institutes of Health|language=en}}</ref>

===Cytokine storm===

A [[Medicine:Cytokine storm|cytokine storm]] can be a complication in the later stages of severe COVID‑19. There is preliminary evidence that [[Chemistry:Hydroxychloroquine|hydroxychloroquine]] may be useful in controlling cytokine storms in late-phase severe forms of the disease.<ref name="pmid32150618">{{cite journal | vauthors = Yao X, Ye F, Zhang M, Cui C, Huang B, Niu P, Liu X, Zhao L, Dong E, Song C, Zhan S, Lu R, Li H, Tan W, Liu D | display-authors = 6 | title = In Vitro Antiviral Activity and Projection of Optimized Dosing Design of Hydroxychloroquine for the Treatment of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) | journal = Clinical Infectious Diseases | volume = | issue = | date = March 2020 | pmid = 32150618 | pmc = 7108130 | doi = 10.1093/cid/ciaa237 }}</ref>

[[Chemistry:Tocilizumab|Tocilizumab]] has been included in treatment guidelines by China's National Health Commission after a small study was completed.<ref name="tocil-1">{{cite news|last1=Liu|first1=Roxanne|last2=Miller|first2=Josh|name-list-format=vanc|url=https://www.reuters.com/article/us-health-coronavirus-china-roche-hldg/china-approves-use-of-roche-arthritis-drug-for-coronavirus-patients-idUSKBN20R0LF|title=China approves use of Roche drug in battle against coronavirus complications|date=3 March 2020|work={{wipe|Reuters}}|access-date=14 March 2020|archive-url=https://web.archive.org/web/20200312204625/https://www.reuters.com/article/us-health-coronavirus-china-roche-hldg/china-approves-use-of-roche-arthritis-drug-for-coronavirus-patients-idUSKBN20R0LF|archive-date=12 March 2020|url-status=live}}</ref><ref name="tocil-2">{{cite document |date=5 March 2020 |title=Effective Treatment of Severe COVID-19 Patients with Tocilizumab |url=http://chinaxiv.org/abs/202003.00026 |publisher=ChinaXiv.org |doi=10.12074/202003.00026|doi-broken-date=2020-07-04 |access-date=14 March 2020|journal=|archive-url=https://web.archive.org/web/20200319022047/http://chinaxiv.org/abs/202003.00026|archive-date=19 March 2020|url-status=live}}</ref> It is undergoing a phase{{nbsp}}2 non-randomised trial at the national level in Italy after showing positive results in people with severe disease.<ref>{{cite web |last1=Ovadia |first1=Daniela |last2=Agenzia |first2=Zoe | name-list-format = vanc |title=COVID-19—Italy launches an independent trial on tocilizumab |url=https://www.univadis.co.uk/viewarticle/covid-19-italy-launches-an-independent-trial-on-tocilizumab-715741 |website=Univadis from Medscape |publisher=Aptus Health |access-date=22 April 2020}}</ref><ref>{{cite web |title=Tocilizumab in COVID-19 Pneumonia (TOCIVID-19) (TOCIVID-19) |url=https://clinicaltrials.gov/ct2/show/NCT04317092 |website=www.clinicaltrials.gov |access-date=22 April 2020}}</ref> Combined with a [[Biology:Ferritin|serum ferritin blood test]] to identify a [[Medicine:Cytokine storm|cytokine storm]] (also called cytokine storm syndrome, not to be confused with [[Medicine:Cytokine release syndrome|cytokine release syndrome]]), it is meant to counter such developments, which are thought to be the cause of death in some affected people.<ref name="tocil-5">{{cite web|url=https://www.vox.com/2020/3/12/21176783/coronavirus-covid-19-deaths-china-treatment-cytokine-storm-syndrome|title=How doctors can potentially significantly reduce the number of deaths from Covid-19|work=Vox|access-date=14 March 2020|date=12 March 2020|archive-url=https://web.archive.org/web/20200319155218/https://www.vox.com/2020/3/12/21176783/coronavirus-covid-19-deaths-china-treatment-cytokine-storm-syndrome|archive-date=19 March 2020|url-status=live}}</ref><ref name="tocil-6">{{cite journal | vauthors = Ruan Q, Yang K, Wang W, Jiang L, Song J | title = Clinical predictors of mortality due to COVID-19 based on an analysis of data of 150 patients from Wuhan, China | journal = Intensive Care Medicine | date = March 2020 | volume = 46 | issue = 5 | pages = 846–848 | pmid = 32125452 | pmc = 7080116 | doi = 10.1007/s00134-020-05991-x }}</ref><ref name="tocil-8">{{cite journal | vauthors = Mehta P, McAuley DF, Brown M, Sanchez E, Tattersall RS, Manson JJ | title = COVID-19: consider cytokine storm syndromes and immunosuppression | journal = Lancet | volume = 395 | issue = 10229 | pages = 1033–1034 | date = March 2020 | pmid = 32192578 | doi = 10.1016/S0140-6736(20)30628-0 | pmc = 7270045 | doi-access = free }}</ref> The interleukin-6 [[Biology:Receptor antagonist|receptor antagonist]] was approved by the [[Organization:Food and Drug Administration|Food and Drug Administration]] (FDA) to undergo a phase III clinical trial assessing its effectiveness on COVID‑19 based on retrospective case studies for the treatment of steroid-refractory cytokine release syndrome induced by a different cause, [[Biology:Chimeric antigen receptor T cell|CAR T cell]] [[Biology:Gene therapy|therapy]], in 2017.<ref name="CancerNetworkTocilizumabTrial">{{cite web |last1=Slater |first1=Hannah | name-list-format = vanc |title=FDA Approves Phase III Clinical Trial of Tocilizumab for COVID-19 Pneumonia |url=https://www.cancernetwork.com/news/fda-approves-phase-iii-clinical-trial-tocilizumab-covid-19-pneumonia |website=www.cancernetwork.com |date=26 March 2020 |publisher=Cancer Network |access-date=22 April 2020}}</ref> To date,{{when|date=June 2020}} there is no randomised, controlled evidence that tocilizumab is an efficacious treatment for CRS. Prophylactic tocilizumab has been shown to increase serum IL-6 levels by saturating the IL-6R, driving IL-6 across the blood-brain barrier, and exacerbating neurotoxicity while having no effect on the incidence of CRS.<ref>{{cite journal | vauthors = Locke FL, Neelapu SS, Bartlett NL, Lekakis LJ, Jacobson CA, Braunschweig I, Oluwole OO, Siddiqi T, Lin Y, Timmerman JM, Reagan PM, Bot A, Rossi JM, Sherman M, Navale L, Jiang Y, Aycock JS, Elias M, Wiezorek JS, Go WY, Miklos DB | display-authors = 6 | title = Preliminary Results of Prophylactic Tocilizumab after Axicabtageneciloleucel (axi-cel; KTE-C19) Treatment for Patients with Refractory,Aggressive Non-Hodgkin Lymphoma (NHL) | journal = Blood | date = 2017 | volume = 130 | issue = Supplement 1 | pages = 1547 | doi = 10.1182/blood.V130.Suppl_1.1547.1547 | doi-broken-date = 2020-06-21 | url = https://ashpublications.org/blood/article/130/Supplement%201/1547/79746}}</ref>

[[Chemistry:Lenzilumab|Lenzilumab]], an anti-GM-CSF [[Biology:Monoclonal antibody|monoclonal antibody]], is protective in murine models for CAR T cell-induced CRS and neurotoxicity and is a viable therapeutic option due to the observed increase of pathogenic GM-CSF secreting T-cells in hospitalised patients with COVID‑19.<ref>{{cite journal | vauthors = Sterner RM, Sakemura R, Cox MJ, Yang N, Khadka RH, Forsman CL, Hansen MJ, Jin F, Ayasoufi K, Hefazi M, Schick KJ, Walters DK, Ahmed O, Chappell D, Sahmoud T, Durrant C, Nevala WK, Patnaik MM, Pease LR, Hedin KE, Kay NE, Johnson AJ, Kenderian SS | display-authors = 6 | title = GM-CSF inhibition reduces cytokine release syndrome and neuroinflammation but enhances CAR-T cell function in xenografts | journal = Blood | volume = 133 | issue = 7 | pages = 697–709 | date = February 2019 | pmid = 30463995 | pmc = 6376281 | doi = 10.1182/blood-2018-10-881722 }}</ref>

The Feinstein Institute of Northwell Health announced in March a study on "a human antibody that may prevent the activity" of IL-6.<ref>{{cite news|url=https://www.longislandpress.com/2020/03/21/northwell-health-initiates-clinical-trials-of-2-covid-19-drugs/|title=Northwell Health Initiates Clinical Trials of 2 COVID-19 Drugs|date=21 March 2020|access-date=23 March 2020|archive-url=https://web.archive.org/web/20200323081238/https://www.longislandpress.com/2020/03/21/northwell-health-initiates-clinical-trials-of-2-covid-19-drugs/|archive-date=23 March 2020|url-status=live}}</ref>

===Passive antibodies===
Transferring purified and concentrated [[Medicine:Immunoglobulin therapy|antibodies]] produced by the [[Biology:Immune system|immune system]]s of those who have recovered from COVID‑19 to people who need them is being investigated as a non-vaccine method of [[Biology:Passive immunity|passive immunisation]].<ref name="pmid-32167489">{{cite journal | vauthors = Casadevall A, Pirofski LA | title = The convalescent sera option for containing COVID-19 | journal = The Journal of Clinical Investigation | volume = 130 | issue = 4 | pages = 1545–1548 | date = April 2020 | pmid = 32167489 | pmc = 7108922 | doi = 10.1172/JCI138003 }}</ref><ref name=":6">{{Cite journal|last=Piechotta|first=Vanessa|last2=Chai|first2=Khai Li|last3=Valk|first3=Sarah J.|last4=Doree|first4=Carolyn|last5=Monsef|first5=Ina|last6=Wood|first6=Erica M.|last7=Lamikanra|first7=Abigail|last8=Kimber|first8=Catherine|last9=McQuilten|first9=Zoe|last10=So-Osman|first10=Cynthia|last11=Estcourt|first11=Lise J.|date=2020-07-10|title=Convalescent plasma or hyperimmune immunoglobulin for people with COVID-19: a living systematic review|url=https://www.ncbi.nlm.nih.gov/pubmed/32648959|journal=The Cochrane Database of Systematic Reviews|volume=7|pages=CD013600|doi=10.1002/14651858.CD013600.pub2|issn=1469-493X|pmid=32648959}}</ref> The safety and effectiveness of [[Medicine:Convalescent plasma|convalescent plasma]] as a treatment option requires further research.<ref name=":6" /> This strategy was tried for SARS with inconclusive results.<ref name="pmid-32167489" /> [[Biology:Neutralisation (immunology)|Viral neutralisation]] is the anticipated [[Chemistry:Mechanism of action|mechanism of action]] by which passive antibody therapy can mediate defence against SARS-CoV-2. The spike protein of SARS-CoV-2 is the primary target for neutralizing antibodies.<ref name=":1">{{Cite journal|last=Ho|first=Mitchell|year=2020|title=Perspectives on the development of neutralizing antibodies against SARS-CoV-2|journal=Antibody Therapeutics|volume=3|issue=2|pages=109–114|doi=10.1093/abt/tbaa009|pmid=32566896|pmc=7291920|doi-access=free}}</ref> It has been proposed that selection of broad-neutralizing antibodies against SARS-CoV-2 and SARS-CoV might be useful for treating not only COVID-19 but also future SARS-related CoV infections.<ref name=":1" /> Other mechanisms, however, such as [[Biology:Antibody-dependent cellular cytotoxicity|antibody-dependent cellular cytotoxicity]] and/or [[Biology:Phagocytosis|phagocytosis]], may be possible.<ref name="pmid-32167489" /> Other forms of passive antibody therapy, for example, using manufactured monoclonal antibodies, are in development.<ref name="pmid-32167489" /> Production of convalescent serum, which consists of the liquid portion of the blood from recovered patients and contains antibodies specific to this virus, could be increased for quicker deployment.<ref name="Pearce-2020-03-13">{{cite web |last=Pearce |first=Katie |name-list-format=vanc |date=13 March 2020 |title=Antibodies from COVID-19 survivors could be used to treat patients, protect those at risk: Infusions of antibody-laden blood have been used with reported success in prior outbreaks, including the SARS epidemic and the 1918 flu pandemic |work=The Hub at Johns Hopkins University |url=https://hub.jhu.edu/2020/03/13/covid-19-antibody-sera-arturo-casadevall/ |access-date=14 March 2020 |archive-url=https://web.archive.org/web/20200314185825/https://hub.jhu.edu/2020/03/13/covid-19-antibody-sera-arturo-casadevall/ |archive-date=14 March 2020 |url-status=live }}</ref>

==See also==
* [[Biology:Coronavirus disease|Coronavirus disease]]s, a group of closely related syndromes
* Coronavirus recession
* ''Decoding COVID-19'', 2020 PBS film documentary about the 2019–2020 COVID-19 pandemic
* [[Biology:Disease X|Disease X]], a WHO term
* Li Wenliang, a doctor who died of COVID-19 after raising awareness of its spread
* [[Unsolved:List of unproven methods against COVID-19|List of unproven methods against COVID-19]]

==Notes==

{{notelist}}

==References==
{{reflist}}

==External links==


===Health agencies===

* [https://www.who.int/emergencies/diseases/novel-coronavirus-2019 Coronavirus disease (COVID-19)] by the [[Organization:World Health Organization|World Health Organization]] (WHO)
* [https://www.cdc.gov/coronavirus/2019-ncov/index.html Coronavirus 2019 (COVID-19)] by the US Centers for Disease Control and Prevention (CDC)
* [https://www.nhs.uk/conditions/coronavirus-covid-19/ Coronavirus (COVID-19)] by the UK National Health Service (NHS)

===Directories===

* {{Curlie|Health/Conditions_and_Diseases/Respiratory_Disorders/COVID-19|COVID-19}}
* [https://openmd.com/directory/covid-19 COVID-19 Resource Directory on OpenMD]

===Medical journals===

* [https://jamanetwork.com/journals/jama/pages/coronavirus-alert Coronavirus Disease 2019 (COVID-19)] by ''JAMA''
* [https://www.bmj.com/coronavirus Coronavirus: News and Resources] by the [[Company:BMJ|BMJ Publishing Group]]
* [https://www.elsevier.com/connect/coronavirus-information-center Novel Coronavirus Information Center] by [[Company:Elsevier|Elsevier]]
* [https://www.thelancet.com/coronavirus COVID-19 Resource Centre] by ''The Lancet''
* [https://www.springernature.com/gp/researchers/campaigns/coronavirus SARS-CoV-2 and COVID-19] by ''Nature''
* [https://www.nejm.org/coronavirus Coronavirus (Covid-19)] by ''The New England Journal of Medicine''
* [https://novel-coronavirus.onlinelibrary.wiley.com/ Covid-19: Novel Coronavirus] by [[Company:Wiley (publisher)|Wiley Publishing]]

===Treatment guidelines===

* {{cite web | title=JHMI Clinical Recommendations for Available Pharmacologic Therapies for COVID-19 | website=The Johns Hopkins University | url=https://www.hopkinsguides.com/hopkins/ub?cmd=repview&type=479-1151&name=13_538747_PDF | format=PDF }}
* {{cite web | title=Bouncing Back From COVID-19: Your Guide to Restoring Movement| website=The Johns Hopkins School of Medicine | url=https://www.hopkinsmedicine.org/physical_medicine_rehabilitation/coronavirus-rehabilitation/_files/impact-of-covid-patient-recovery.pdf }}
* {{cite web | title=Guidelines on the Treatment and Management of Patients with COVID-19 | website=Infectious Diseases Society of America | url=https://www.idsociety.org/globalassets/idsa/practice-guidelines/covid-19/treatment/idsa-covid-19-gl-tx-and-mgmt-v2.1.0.pdf | lay-url=https://www.idsociety.org/practice-guideline/covid-19-guideline-treatment-and-management/ }}
* {{cite web | title=Coronavirus Disease 2019 (COVID-19) Treatment Guidelines | website=National Institutes of Health | url=https://files.covid19treatmentguidelines.nih.gov/guidelines/covid19treatmentguidelines.pdf | lay-url=https://www.covid19treatmentguidelines.nih.gov/whats-new/ }}

{{medical resources| ICD10 = {{ICD10|U07.1}}, {{ICD10|U07.2}}}}
{{Respiratory pathology}}
{{Viral diseases}}

[[Category:Zoonoses]]

{{Sourceattribution|Coronavirus disease 2019|1}}