ATLANTA, June 23 (Our Illinois Times) — A rare tick-borne virus that can infect the brain may move fast enough to matter during ordinary outdoor activities, with CDC guidance and published studies saying Powassan virus can be transmitted soon after a tick attaches.
The virus remains uncommon in the United States, but the CDC says reported cases have increased in recent years. Most cases occur in the Northeast and Great Lakes regions, especially during the months when ticks are most active from late spring through mid-fall.
Powassan virus is spread by infected ticks, including blacklegged or deer ticks, groundhog ticks and squirrel ticks, according to the CDC. The Defense Centers for Public Health–Aberdeen says studies show transmission can occur in as little as 15 minutes of feeding, while a peer-reviewed case report said human infection can happen within hours of attachment.
That speed is part of what makes the virus notable for people who spend time outdoors in tick habitat. The CDC says Powassan infection can be mild or asymptomatic, but it can also progress to encephalitis or meningitis.
When severe, the illness can cause confusion, loss of coordination, speech problems, seizures and paralysis, according to the CDC. The agency says older adults, children and immunocompromised people are at higher risk of neuroinvasive disease.
CDC guidance says initial symptoms can include fever, headache, vomiting and weakness. It also says there are no vaccines to prevent Powassan virus disease and no medicines to treat it.
The CDC says about 10% of people with Powassan neuroinvasive disease die, and about half of survivors have long-lasting neurologic deficits. The Defense Centers for Public Health–Aberdeen says CDC counted about 397 reported cases from 2004 through 2024.
