Powassan encephalitis

Main article: Tick-borne meningoencephalitis

Powassan encephalitis
Specialty	Infectious diseases

Powassan encephalitis, caused by the Powassan virus (POWV), a flavivirus also known as the deer tick virus, is a form of arbovirus infection that results from tick bites. It can occur as a co-infection with Lyme disease, as both are transmitted to humans by the same species of tick. ^[1] Over the last decade, there has been a surge in the number of cases and an expansion of its geographic range. In the United States, cases have been documented primarily in the northeast. ^[2] The disease was first isolated from the brain of a boy who died of encephalitis in Powassan, Ontario, in 1958. ^[3] This disease is classified as a zoonosis, originating in animals, often found in rodents and ticks, with subsequent transmission to humans. The virus shares antigenic similarities with the Far Eastern tick-borne encephalitis viruses. ^[4]

Signs and symptoms

Signs and symptoms manifest within 7–10 days and include fever, headache, partial paralysis, confusion, nausea, and even coma.^{[ citation needed ]}

Treatment

There is currently no established treatment. ^[5]

Prognosis

Half of all cases result in permanent neurological damage, and 10-15% result in death.^{[ citation needed ]}

References

1. Caulfield AJ, Pritt BS (December 2015). "Lyme Disease Coinfections in the United States". Clinics in Laboratory Medicine. 35 (4): 827–46. doi:10.1016/j.cll.2015.07.006. PMID   26593260.
2. "Cumulative human disease cases reported to CDC ArboNET for 2015". United States Geological Survey. Archived from the original on 2016-12-15. Retrieved 2015-11-27.
3. McLEAN DM, DONOHUE WL (1 May 1959). "Powassan virus: isolation of virus from a fatal case of encephalitis". Canadian Medical Association Journal. 80 (9): 708–11. PMC   1830849 . PMID   13652010.
4. CASALS J (13 February 1960). "Antigenic relationship between Powassan and Russian spring-summer encephalitis viruses". Canadian Medical Association Journal. 82 (7): 355–8. PMC   1937779 . PMID   13808112.
5. Hinten SR, Beckett GA, Gensheimer KF, et al. (December 2008). "Increased recognition of Powassan encephalitis in the United States, 1999-2005". Vector Borne Zoonotic Dis. 8 (6): 733–40. doi:10.1089/vbz.2008.0022. PMID   18959500.