Increase in Powassan Virus Cases Reported in the U.S.

Cases of Powassan virus, a rare tick-borne illness, have been increasing in the United States in recent years. The virus, which can be transmitted by infected woodchuck ticks or deer ticks, can lead to symptoms such as weakness, fever, headache, and vomiting, according to the Centers for Disease Control and Prevention (CDC). There are currently no treatments or vaccines available for the virus, which can also cause meningitis or encephalitis. Severe symptoms may include seizures, confusion, difficulty speaking, and loss of coordination. The first known case of Powassan virus was reported in 1958, when a 4-year-old boy named Lincoln Byers died from an unidentified virus. Researchers later identified the virus in a tick collected from a dead squirrel. Although the virus is rare, reported cases in the U.S. have risen from seven in 2015 to 76 in 2025. Most infections occur from late spring to mid-fall when tick populations are most active. Dr. Jorge P. Parada, a medical adviser at the National Pest Management Association, noted that Powassan can be transmitted in as little as 15 minutes after a tick bite, compared to Lyme disease, which typically requires a 36- to 48-hour attachment time for transmission.