Cases of Powassan virus, which spreads from deer ticks, have become more common in the last decade.
, also known as deer ticks, but humans can’t pass it to each other. Many people who get infected don’t develop symptoms at all. But in rare cases, Powassan virus can cause a disease characterized by brain inflammation or meningitis, the swelling of membranes surrounding the brain and spinal cord.
In the U.S., the virus is commonly found in the Northeastern and Great Lakes regions, where deer ticks are more common. The majority of cases recorded in the last decade have been in Massachusetts, Minnesota, Wisconsin and New York.Centers for Disease Control and Prevention identified Eleven percent of the 194 cases documented in the U.S. from 2011 to 2020 were fatal. That's consistent with the virus'sThose who get sick usually start to feel symptoms one week to one month after they get infected. The illness often begins with fever, headache, vomiting or weakness. From there, more severe symptoms can occur, like confusion, loss of coordination, difficulty speaking and seizures. More than 90 percent of the U.S. cases in the last decade involved neuroinvasive disease.