Rare, tick-borne Powassan virus worries some experts about possible spread.
Powassan Virus, which is rarer and more deadly than the bacteria that causes Lyme, is now carried by the deer tick, which has a broad range and often bites humans.
Until recently, the disease was borne only by a tick that does not bite humans, and the risk was all but non-existent.
Powassan virus, which can cause death and permanent bodily damage, has the potential to develop into a serious public health problem.
The CDC has a record of 75 cases of the severe disease between 2006 and 2015; it remains far less common than Lyme. But it is transmitted more quickly – within 15 minutes from the time the tick bites. Lyme takes 36 to 48 hours, according to the CDC.
Powassan attacks the nervous system and can infect the brain, causing encephalitis, and it can infect the lining of the brain, causing meningitis. The symptoms range from none to death, according to the Yale School of Public Health.
Serious infections cause the most severe symptoms including headache, muscle weakness, confusion and seizures about a week or more after infection.
About 10 percent of the people who develop meningitis and brain-swelling die. About half the people who survive have permanent neurological damage, including memory problems, facial tics, and blurred vision.
There is no vaccine or specific treatment other than providing comfort, keeping patients hydrated and in the worst cases providing supportive therapy that will allow the immune system to resolve the illness before the patient dies.
Many patients, however, show no symptoms at all, which is why researchers have so much trouble knowing exactly how many people have been infected.
The cause for concern is the recent proof that the deer tick now carries the virus. Discovered in the 1950s in Powassan, Ontario, until three decades ago, it was only carried by a tick that didn’t bite humans.
But with the jump to the deer tick, the spread may be inevitable. Studies of wildlife, who also can become infected, show Powassan increasing in New England and parts of the upper Midwest.