Medicine:Emergomycosis

From HandWiki

Emergomycosis, previously known as emmonsiosis, is a systemic fungal infection that can affect the lungs, generally always affects the skin and can become widespread.[1][2] It is endemic to South Africa and primarily affects individuals with HIV/AIDS and other immunocompromised people, although it can also infect people with healthy immune systems.[3] The lesions in the skin look like small red bumps and patches with a dip, ulcer and dead tissue in the centre.[4]

It is caused by the Emergomyces species, a novel dimorphic fungus, previously classified under the genus Emmonsia.[5] These fungi are found in soil and transmitted by breathing in its spores from the air.[2] Inside the body it converts to yeast-like cells which then cause disease and invade beyond the lungs.[2] Diagnosis is by skin biopsy and its appearance under the microscope.[6] It is difficult to distinguish from histoplasmosis.[5][7]

Treatment is usually with amphotericin B.[5] Emergomycosis can be fatal.[5]

Emergomycosis is rare.[2] The disseminated type is more prevalent in South Africa, particularly in people with HIV.[5] The disease is named for Chester Wilson Emmons who first described Emmonsia.[8]

Signs and symptoms

The most common clinical manifestations of emergomycosis are:[9]

Generally, all cases have involvement of the skin.[6] The lesions look like small red bumps and patches with a dip, ulcer and dead tissue in the centre.[4] There may be several lesions and their distribution can be widespread.[2] The lungs may be affected.[5][4]

Cause

File:Pathogenesis of Emergomycosis (Emmonsiosis).jpg
A diagram showing the pathogenesis of infection with the dimorphic fungus emergomyces

Emergomycosis is caused by the Emergomyces species, a dimorphic fungus, previously classified under the genus Emmonsia.[5][10] Following a revised taxonomy in 2017 based on DNA sequence analyses, five of these Emmonsia-like fungi have been placed under the separate genus Emergomyces.[5] These include Emergomyces pasteurianus, Emergomyces africanus, Emergomyces canadensis, Emergomyces orientalis and Emergomyces europaeus.[5][11] Emergomyces africanus causes over 2/3 of documented human cases of emergomycosis.[3] Cases in Europe are much rarer, but when they do occur, they are usually due to E. pasteurianus.[9]

The fungus is found in soil, where it normally lives as a mold that does not cause disease.[6] Transmission is by breathing in fungal spores from the air.[6] Inside the body it converts to yeast-like cells which then cause disease and invade beyond the lungs.[6] In people with HIV, Emergomycosis has been associated with Immune reconstitution inflammatory syndrome following initiating antiretroviral treatment.[2]

The fungus only undergoes its transformation into yeast once it reaches the terminal (deep) portions of the lungs. It does not actually cause significant respiratory infection in most cases, but rather tends to spread hematogenously or possibly through lymphatics to other organs, where it can cause life-threatening infections such as endocarditis.[9]

The disease is most commonly observed among people who have a weakened immune system and risk factors include HIV, organ transplant and steroid use.[2][5] It is especially associated with HIV+ individuals with CD4+ T-cell counts under 100 cells/mm3.[3]

Diagnosis

File:Pathology images of Emergomyces orientalis.jpg
Various pathology images from a case of emergomycosis reported in China

Diagnosis is by skin biopsy and its appearance under the microscope.[6] In its pathogenic form, it is a budding yeast. As of 2023, there is no clinical guideline or well-defined diagnostic pathway for emergomycosis.[9]

Differential diagnosis

Generally, emergomycosis maybe difficult to distinguish from histoplasmosis.[7][9] Other conditions that appear similar include tuberculosis,[6] blastomycosis, sporotrichosis, chicken pox, Kaposi's sarcoma and drug reactions.[4]

Treatment

Treatment of emergomycosis usually includes amphotericin B as the first-line drug of choice, replaced by azoles after several weeks due to the high toxicity of amphotericin B.[5][9] There is some very early evidence that triazoles may yield better results when used as the first-line or sole antifungal drug of choice.[6]

Prognosis

Studies have identified fatality rates of 40-50% in cases of emergomycosis.[3][6][9] However, a significant portion of non-survivors are individuals diagnosed post-mortem (after death) who did not receive any treatment.[6] The mortality rate is thought to be similar for symptomatic people who are immunocompetent as they are for people with HIV or other causes of immunodeficiency.[3]

History

The disease was originally named for Chester Wilson Emmons who first described Emmonsia.[8] The disease was thought to be a rare condition of the lung.[1] Early cases may have been misdiagnosed as histoplasmosis.[7]

Other animals

The genus Emmonsia can cause adiaspiromycosis, a lung disease in wild animals.[8] Emergomycosis has also been documented in animals in areas where it does not normally infect humans.[12]

References

  1. ↑ 1.0 1.1 "ICD-11 - ICD-11 for Mortality and Morbidity Statistics". https://icd.who.int/browse11/l-m/en#/http%3a%2f%2fid.who.int%2ficd%2fentity%2f1357848258. 
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Schwartz, Ilan S.; Govender, Nelesh P.; Sigler, Lynne; Jiang, Yanping; Maphanga, Tsidiso G.; Toplis, Barbra; Botha, Alfred; Dukik, Karolina et al. (19 September 2019). "Emergomyces: The global rise of new dimorphic fungal pathogens" (in en). PLOS Pathogens 15 (9). doi:10.1371/journal.ppat.1007977. ISSN 1553-7374. PMID 31536607. 
  3. ↑ 3.0 3.1 3.2 3.3 3.4 Vinayagamoorthy, Kalaiselvi; Gangavaram, Dinesh Reddy; Skiada, Anna; Prakash, Hariprasath (2023-10-23). "Emergomycosis, an Emerging Thermally Dimorphic Fungal Infection: A Systematic Review". Journal of Fungi (Basel, Switzerland) 9 (10): 1039. doi:10.3390/jof9101039. ISSN 2309-608X. PMID 37888295. 
  4. ↑ 4.0 4.1 4.2 4.3 Kutzner, Heinz; Kempf, Werner; Feit, Josef; Sangueza, Omar (2021). "2. Fungal infections" (in en). Atlas of Clinical Dermatopathology: Infectious and Parasitic Dermatoses. Hoboken: Wiley Blackwell. p. 102. ISBN 978-1-119-64706-5. https://books.google.com/books?id=M30REAAAQBAJ&pg=PA102. 
  5. ↑ 5.00 5.01 5.02 5.03 5.04 5.05 5.06 5.07 5.08 5.09 5.10 Samaddar, Arghadip; Sharma, Anuradha (2021). "Emergomycosis, an Emerging Systemic Mycosis in Immunocompromised Patients: Current Trends and Future Prospects". Frontiers in Medicine 8. doi:10.3389/fmed.2021.670731. ISSN 2296-858X. PMID 33968970. 
  6. ↑ 6.00 6.01 6.02 6.03 6.04 6.05 6.06 6.07 6.08 6.09 Schwartz, Ilan S.; Govender, Nelesh P.; Corcoran, Craig; Dlamini, Sipho; Prozesky, Hans; Burton, Rosie; Mendelson, Marc; Taljaard, Jantjie et al. (15 September 2015). "Clinical Characteristics, Diagnosis, Management, and Outcomes of Disseminated Emmonsiosis: A Retrospective Case Series". Clinical Infectious Diseases 61 (6): 1004–1012. doi:10.1093/cid/civ439. ISSN 1537-6591. PMID 26060283. 
  7. ↑ 7.0 7.1 7.2 Calonje, J. Eduardo; Grayson, Wayne (2020). "18. Infectious diseases of the skin". in Calonje, J. Eduardo; Brenn, Thomas; Lazar, Alexander J. et al. (in en). McKee's Pathology of the Skin, 2 Volume Set (5th ed.). Elsevier. pp. 959–960. ISBN 978-0-7020-6983-3. https://books.google.com/books?id=pMN1DwAAQBAJ&pg=PA959. 
  8. ↑ 8.0 8.1 8.2 Henry, Ronnie Etymologia: Emmonsia. Emerging Infectious Diseases. 2017;23(2):348. doi:10.3201/eid2302.et2302.
  9. ↑ 9.0 9.1 9.2 9.3 9.4 9.5 9.6 Ibe, Chibuike; Mnyambwa, Nicholaus P.; Mfinanga, Sayoki G. (2023). "Emergomycosis in Africa: Time to Pay Attention to This Emerging Deadly Fungal Infection". International Journal of General Medicine 16: 2313–2322. doi:10.2147/IJGM.S403797. ISSN 1178-7074. PMID 37309324. 
  10. ↑ Govender, Nelesh P.; Grayson, Wayne (2019). "Emergomycosis (Emergomyces africanus) in Advanced HIV Disease". Dermatopathology 6 (2): 63–69. doi:10.1159/000495405. ISSN 2296-3529. PMID 31700845. 
  11. ↑ Jiang, Yanping; Dukik, Karolina; Muñoz, Jose F.; Sigler, Lynne; Schwartz, Ilan S.; Govender, Nelesh P.; Kenyon, Chris; Feng, Peiying et al. (1 May 2018). "Phylogeny, ecology and taxonomy of systemic pathogens and their relatives in Ajellomycetaceae (Onygenales): Blastomyces, Emergomyces, Emmonsia, Emmonsiellopsis" (in en). Fungal Diversity 90 (1): 245–291. doi:10.1007/s13225-018-0403-y. ISSN 1878-9129. https://link.springer.com/article/10.1007/s13225-018-0403-y. 
  12. ↑ Hubálek, Z. (April 1999). "Emmonsiosis of wild rodents and insectivores in Czechland". Journal of Wildlife Diseases 35 (2): 243–249. doi:10.7589/0090-3558-35.2.243. ISSN 0090-3558. PMID 10231750. 



Retrieved from "https://handwiki.org/wiki/index.php?title=Medicine:Emergomycosis&oldid=4428822"