Powassan virus one of many diseases transmitted by deer ticks
Powassan virus, a rare tick-borne neuroinvasive disease, made headlines recently when a 5-month-old baby became the first person diagnosed in Connecticut.
Over the past decade, about 75 cases of Powassan virus in the United States were reported to the Centers for Disease Control (CDC).
Twenty of those cases were in Minnesota.
Sixteen were in Wisconsin, 16 in New York State, eight in Massachusetts and a smattering in New Jersey, New Hampshire, Pennsylvania and Virginia.
By comparison, there were 9,026 reported cases of Lyme Disease in Minnesota during that same time period (2006-2015).
While rare, the Powassan virus is worrisome because it can infect the central nervous system and cause encephalitis (inflammation of the brain) and meningitis (inflammation of the membranes that surround the brain and spinal cord). Patients may suffer long-term neurologic symptoms, such as headaches and memory problems.
It's fatal in approximately 10 percent of cases nationwide.
The first recorded death in Minnesota occurred in June 2011. According to the Minnesota Department of Health (MDH), a woman in her 60s from northern Minnesota died from a brain infection.
Statistics for 2016 have not yet been released by MDH.
The virus is named after Powassan, Ontario, where it was first discovered in 1958.
It was first detected in Minnesota in 2008 in a Cass County child who was exposed near home.
Powassan virus can be transmitted by the blacklegged tick (also called the "deer tick"), which can also carry Lyme disease, anaplasmosis and babesiosis.
As most Minnesotans know, the blacklegged tick is abundant during warm weather months in many wooded areas of the state. The greatest risk for tick bites are from April through July and September through October.
When a tick infected with Powassan virus attaches to a person, it might take only minutes of tick attachment for the virus to be transmitted.
Symptoms of infection usually appear within one to four weeks of a tick bite. Signs can include fever, headache, vomiting, weakness, confusion, seizures and memory loss.
According to the CDC, "long-term neurologic problems may occur. There is no specific treatment, but people with severe Powassan virus illnesses often need to be hospitalized to receive respiratory support, intravenous fluids, or medications to reduce swelling in the brain."
There is no specific medicine to cure or treat Powassan virus.
"Reducing exposure to ticks is the best defense against tick-borne diseases," says a MDH pamphlet about the pathogen.