Powassan encephalitis

Main article: Tick-borne meningoencephalitis

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]

Powassan encephalitis
Specialty	Infectious diseases

Signs and symptoms

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

Diagnosis

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]}