Skip to content

HealthUnited States2 min read

Rare tick-borne Powassan virus can spread quickly and damage the brain, CDC says

The CDC warns that the rare, tick-borne Powassan virus can spread within minutes of a bite, causing severe brain inflammation and paralysis.

Share

Topics

Close-up of a dark brown and black tick on a green leaf, legs splayed outward.

ATLANTA, June 23 (Our Illinois Times) — For people spending time outdoors in parts of the Northeast and Great Lakes, a tick bite can carry a fast-moving risk: Powassan virus is rare, but the CDC says it can cause brain inflammation, seizures and paralysis, and public-health officials say it may spread within minutes of a tick attaching.

The Centers for Disease Control and Prevention says reported Powassan cases have increased in recent years, even though the disease remains uncommon. Most U.S. cases are reported in the Northeast and Great Lakes regions, especially from late spring through mid-fall, when ticks are most active.

The CDC says early symptoms can include fever, headache, vomiting and weakness. In severe cases, Powassan can cause encephalitis or meningitis, which can lead to confusion, loss of coordination, speech problems, seizures and paralysis.

CDC clinical guidance says there are no vaccines to prevent Powassan virus disease and no medicines to treat it. The agency says about 10% of people with neuroinvasive disease die, and about half of survivors have long-lasting neurologic deficits.

The Defense Centers for Public Health-Aberdeen says studies show infected ticks can transmit the virus in as little as 15 minutes of feeding. A peer-reviewed case report said human transmission can occur within hours of attachment, while review articles describe Powassan as the only tick-borne encephalitis virus found in the United States.

CDC says older adults, children and immunocompromised people are at higher risk of neuroinvasive disease. The agency also says Powassan can rarely be spread through blood transfusion.

Share

Topics

Stephanie Ramirez

Stephanie Ramirez is a senior California reporter for Times Media Service, based in Sacramento, California. Ramirez covers California elections and state politics, including government decisions and public policy and the practical effects on residents across the state. Ramirez holds a master's degree in communication with a focus on journalism and grew up in Sacramento, California.

Write to Stephanie