Biology:Slow virus

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A slow virus is a virus, or a viruslike agent, etiologically associated with a slow virus disease. A slow virus disease is a disease that, after an extended period of latency, follows a slow, progressive course spanning months to years, frequently involves the central nervous system, and in most cases progresses to death. Examples of slow virus diseases include HIV/AIDS, caused by the HIV virus,[1] subacute sclerosing panencephalitis, the rare result of a measles virus infection,[2] and Paget's disease of bone (osteitis deformans), which may be associated with paramyxoviruses, especially the measles virus and the human respiratory syncytial virus.[3]

Characteristics

Every infectious agent is different, but in general, slow viruses:[4]

  • Cause an asymptomatic primary infection
  • Have a long incubation period ranging from months to years
  • Follow a slow but relentless progressive course leading to death
  • Tend to have a genetic predisposition
  • Often re-emerge from latency if the host becomes immuno-compromised

Additionally, the immune system seems to plays a limited role, or no role, in protection from many of these slow viruses. This may be due to the slow replication rates some of these agents exhibit,[5] preexisting immunosuppression (as in the cases of JC virus and BK virus),[6] or, in the case of prions, the identity of the agent involved.[7]

Scope

Slow viruses cause a variety of diseases, including cancer.

Examples of viral agents
Virus Virus family Disease Typical latency Transmitted by
JC virus (Human polyomavirus 2) Polyomavirus Progressive multifocal leukoencephalopathy Years to Life§ Unknown; possibly contaminated water[6]
Measles virus Paramyxovirus Subacute sclerosing panencephalitis 1–10 years Respiratory droplets[8]
Rubella virus Togaviridae Progressive rubella panencephalitis 10–20 years Respiratory droplets[9]
Rabies virus Rhabdoviridae Rabies 3–12 weeks Bite of an infected animal[10]
Human papillomavirus infection Papillomaviridae Cancers of the cervix, oropharynx, vulva, anal, penis, vagina, rectum. Years Sexual activity[11]
§JC virus & BK virus only cause disease in immunocompromised patients

Kuru- A form of Transmissible spongiform encephalopathy

Was once thought to be due to a slow virus but is now known to be the result of Prion disease.[citation needed]

See also

References

  1. "About HIV/AIDS | HIV Basics | HIV/AIDS" (in en-us). U.S. Centers for Disease Control and Prevention. 2019-02-28. https://www.cdc.gov/hiv/basics/whatishiv.html. 
  2. "Subacute Sclerosing Panencephalitis". PubMed Health. National Center for Biotechnology Information, U.S. National Library of Medicine. https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002392. 
  3. "Paget disease of bone". The Journal of Clinical Investigation 115 (2): 200–208. February 2005. doi:10.1172/JCI24281. PMID 15690073. 
  4. "Slow Viruses & Prions.". Medical Microbiology & Immunology: A Guide to Clinical Infectious Diseases (16th ed.). McGraw Hill. 2020. https://accessmedicine.mhmedical.com/content.aspx?bookid=2867&sectionid=242761049. 
  5. "Underwhelming the immune response: effect of slow virus growth on CD8+-T-lymphocyte responses". Journal of Virology 78 (5): 2247–2254. March 2004. doi:10.1128/jvi.78.5.2247-2254.2004. PMID 14963121. 
  6. 6.0 6.1 "BK and JC virus: a review". The Journal of Infection 68 (Suppl 1): S2–S8. January 2014. doi:10.1016/j.jinf.2013.09.009. PMID 24119828. 
  7. "Prion disease and the innate immune system". Viruses 4 (12): 3389–3419. December 2012. doi:10.3390/v4123389. PMID 23342365. 
  8. "Subacute sclerosing panencephalitis". Postgraduate Medical Journal 78 (916): 63–70. February 2002. doi:10.1136/pmj.78.916.63. PMID 11807185. 
  9. "[Progressive rubella panencephalitis]" (in Japanese). Nihon Rinsho. Japanese Journal of Clinical Medicine 55 (4): 922–925. April 1997. PMID 9103895. 
  10. "Human rabies: neuropathogenesis, diagnosis, and management". The Lancet. Neurology 12 (5): 498–513. May 2013. doi:10.1016/S1474-4422(13)70038-3. PMID 23602163. 
  11. "Human Papillomavirus Infection". Diagnostic Pathology: Infectious Diseases. Elsevier Health Sciences. 2015. p. 40. ISBN 978-0-323-40037-4. https://books.google.com/books?id=YJ_uCQAAQBAJ&pg=PA40.