ATLANTA, June 23 (Our Illinois Times) — A rare tick-borne virus in the United States can infect the brain and, in some cases, spread within minutes of a tick bite, according to the Centers for Disease Control and Prevention and peer-reviewed studies.
Powassan virus disease is uncommon, but the CDC says reported cases have increased in recent years. The agency says most U.S. infections occur in the Northeast and Great Lakes regions, especially during the months when ticks are most active from late spring through mid-fall.
The CDC says the infection can start with fever, headache, vomiting and weakness. In more severe cases, it can lead to encephalitis or meningitis, and symptoms can include confusion, loss of coordination, speech problems, seizures and paralysis.
CDC clinical guidance says Powassan neuroinvasive disease is fatal in about 10% of cases, and about half of survivors have long-lasting neurologic problems. The agency also says there are no vaccines to prevent Powassan virus disease and no medicines to treat it.
Studies cited by the U.S. military’s Defense Centers for Public Health–Aberdeen say the virus can be transmitted in as little as 15 minutes of tick feeding. A peer-reviewed case report in the medical literature said human transmission can occur within hours of attachment, and other reviews describe the virus as able to spread faster than many other tick-borne diseases.
The main tick species named by the CDC are the blacklegged or deer tick, the groundhog tick and the squirrel tick. CDC guidance says older adults, children and people with weakened immune systems are at higher risk of neuroinvasive disease.
Powassan virus infection can be mild or cause no symptoms at all, but CDC guidance says neuroinvasive disease can progress rapidly and leave permanent injury. The Defense Centers for Public Health–Aberdeen says Powassan is the only tick-borne encephalitis virus found in the United States.
The virus was first identified in 1958 in Powassan, Ontario, and the first U.S. case was diagnosed in New Jersey in 1970, according to the military public-health office.
