Slow virus

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

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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

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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]
BK virus | Polyomavirus | BK nephropathy, bladder cancer[8] | Years to life§ | Unknown; possibly respiratory spread/urine; possibly contaminated water[6]
Measles virus | Paramyxovirus | Subacute sclerosing panencephalitis | 1–10 years | Respiratory droplets[9]
Rubella virus | Togaviridae | Progressive rubella panencephalitis | 10–20 years | Respiratory droplets[10]
Rabies virus | Rhabdoviridae | Rabies | 3–12 weeks | Bite of an infected animal[11]
Human papillomavirus infection | Papillomaviridae | Cancers of the cervix, oropharynx, vulva, anal, penis, vagina and rectum.  | Years  | Sexual activity[12]

§JC virus & BK virus only cause disease in immunocompromised patients

## See also

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* Clinical latency
* Virus latency

## References

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1. ^ "About HIV/AIDS | HIV Basics | HIV/AIDS". U.S. Centers for Disease Control and Prevention. 2019-02-28. Retrieved 2019-03-05.
2. ^ "Subacute Sclerosing Panencephalitis". PubMed Health. National Center for Biotechnology Information, U.S. National Library of Medicine. Archived from the original on 25 February 2014. Retrieved 10 February 2012.
3. ^ Roodman GD, Windle JJ (February 2005). "Paget disease of bone". The Journal of Clinical Investigation. 115 (2): 200–208\. doi:10.1172/JCI24281. PMC 546434. PMID 15690073.
4. ^ Levinson W, Chin-Hong P, Joyce EA, Nussbaum J, Schwartz B, eds. (2020). "Slow Viruses & Prions.". Medical Microbiology & Immunology: A Guide to Clinical Infectious Diseases (16th ed.). McGraw Hill.
5. ^ Bocharov G, Ludewig B, Bertoletti A, Klenerman P, Junt T, Krebs P, et al. (March 2004). "Underwhelming the immune response: effect of slow virus growth on CD8+-T-lymphocyte responses". Journal of Virology. 78 (5): 2247–2254\. doi:10.1128/jvi.78.5.2247-2254.2004. PMC 369240. PMID 14963121.
6. ^ a b c Pinto M, Dobson S (January 2014). "BK and JC virus: a review". The Journal of Infection. 68 (Suppl 1): S2 – S8. doi:10.1016/j.jinf.2013.09.009. PMID 24119828.
7. ^ Bradford BM, Mabbott NA (December 2012). "Prion disease and the innate immune system". Viruses. 4 (12): 3389–3419\. doi:10.3390/v4123389. PMC 3528271. PMID 23342365.
8. ^ Haridy R (2022-02-25). "The new science linking cancer, schizophrenia and MS to viral infections". New Atlas. Retrieved 2022-02-28.
9. ^ Garg RK (February 2002). "Subacute sclerosing panencephalitis". Postgraduate Medical Journal. 78 (916): 63–70\. doi:10.1136/pmj.78.916.63. PMC 1742261. PMID 11807185.
10. ^ Kuroda Y, Matsui M (April 1997). "[Progressive rubella panencephalitis]". Nihon Rinsho. Japanese Journal of Clinical Medicine (in Japanese). 55 (4): 922–925\. PMID 9103895.
11. ^ Hemachudha T, Ugolini G, Wacharapluesadee S, Sungkarat W, Shuangshoti S, Laothamatas J (May 2013). "Human rabies: neuropathogenesis, diagnosis, and management". The Lancet. Neurology. 12 (5): 498–513\. doi:10.1016/S1474-4422(13)70038-3. PMID 23602163. S2CID 1798889.
12. ^ Soong TR, Milner Jr DA (2015). "Human Papillomavirus Infection". In Milner Jr DA, Pecora N, Solomon I, Soong TR (eds.). Diagnostic Pathology: Infectious Diseases. Elsevier Health Sciences. p. 40\. ISBN 978-0-323-40037-4. Archived from the original on 11 September 2017.