Powassan virus, a rare but potentially fatal tick-borne illness, is spreading in the United States, with cases reported in multiple states including New York, Massachusetts, and Wisconsin. The virus, first identified in 1958 in Powassan, Ontario, after a young boy died from encephalitis, is transmitted by the black-legged tick (Ixodes scapularis) and the groundhog tick (Ixodes cookei).
According to the Centers for Disease Control and Prevention (CDC), there have been 20 to 100 cases reported annually in recent years, with about 10% of cases being fatal. Symptoms include fever, headache, vomiting, weakness, confusion, seizures, and memory loss. There is no specific treatment or vaccine for Powassan virus; care is supportive.
Experts warn that climate change may be expanding the range of ticks, increasing human exposure. The CDC advises prevention through avoiding tick habitats, using insect repellent, and performing tick checks after outdoor activities.
