Tick-borne Powassan virus can kill – How to protect yourself
By Cara Murez
health day reporter
THURSDAY, May 25, 2023 (HealthDay News) — Robert Weymouth, 58, of Portland, Maine, died this year from a tick bite.
You’ve probably heard of Lyme disease and the problems it can cause when transmitted to a human through the bite of a deer tick. But Lyme isn’t the only tick-borne disease in the woods.
Powassan virus – a rare and incurable infection – is also transmitted by ticks. It was the bite that led to life-threatening complications in the case of this Maine truck driver.
Weymouth — Powassan’s third death since 2015 in Maine and first this year — likely contracted the virus in the state, according to the Maine Centers for Disease Control and Prevention. He developed neurological symptoms and died in hospital.
His widow, Annemarie Weymouth, now warns others to protect themselves from the disease.
“He was in there, but he couldn’t move his body. He could point to words on a board. He pointed to ‘scared’, ‘scared’, ‘frustrated’,” Weymouth said. CBS News.
True case numbers are unknown
“Because it’s relatively rare to make the diagnosis, there’s a lot we don’t know,” said Dr. Eugene Shapiro, professor of pediatrics and epidemiology at Yale University.
But here’s what we do know:
The United States Centers for Disease Control and Prevention received 189 reports of Powassan infection between 2012 and 2021.
Most US cases of Powassan virus occur in the Northeast and Great Lakes regions. Maine had four cases last year alone.
Although ticks are arachnids like spiders, the virus is not so different from some mosquito-borne viruses, such as dengue fever and Zika. Other than being transmitted by a tick, the Powassan virus is “in no way, shape or form anything like Lyme disease,” Shapiro said.
The Powassan virus is closely related to something called tick-borne encephalitis, which is a virus seen particularly in central and eastern Europe and Eurasia, Shapiro said.
The Powassan virus only seriously affects a small number of people each year. But many more may be asymptomatic or have minor or flu-like symptoms and go undiagnosed.
The virus gets its name from its discovery in a 5-year-old boy who died of the virus in the late 1950s in Powassan, Ontario, Canada.
Experts believe it was transmitted primarily by the groundhog tick, which typically did not feed on humans. Instead, it mainly ate skunks, groundhogs and squirrels, Shapiro said.
At some point it moved on to deer ticks, and these are ticks that usually bite humans.
There are still many mysteries to be unraveled regarding the Powassan virus. For example, although some research has suggested that up to 5% of deer ticks in parts of Connecticut test positive for the virus, this does not manifest in high numbers of human infections in Powassan, Shapiro said.
But cases are rising, according to CDC figures, said Dr. Nicole Baumgarth, an immunologist at the Johns Hopkins School of Public Health. Still, it’s unclear if there are actually more people infected or if doctors are testing it more frequently, she said.
“There’s no treatment, other than some kind of general support of someone with the disease,” Baumgarth said. “The most serious disease associated with Powassan is inflammation of the brain or encephalitis, but not everyone infected with this virus will develop these very severe cases.”
Other symptoms may include fever, chills, fatigue, rash on the trunk, muscle weakness, nausea, vomiting, dizziness and stiff neck, according to Yale Medicine.
However, the vast majority of those infected will likely have no or only minor symptoms and will go undiagnosed.
For those with symptoms severe enough to diagnose, usually encephalitis, the death rate is between 10% and 30%, Shapiro said.
Keep in mind, however, that it is rare. “It’s kind of scary, but it’s a rare disease,” Baumgarth said.
With Lyme disease, the tick must be attached for about a day to transmit its infection. Removing the tick quickly puts you at a low risk of infection. If it’s been longer, a single dose of doxycycline is moderately effective in preventing infection. However, Baumgarth noted that the Powassan pathogen can be transmitted faster than Lyme bacteria, “so it’s hard to get past that.”
Prevention is the best cure
You can take certain precautions to limit exposure to ticks when spending time in grassy or wooded areas that may harbor ticks, Baumgarth and Shapiro said.
Wear long sleeves and long pants, with the bottom of the pants tucked into the socks.
Wear light-colored clothing so that ticks are visible. Remove them right away.
Use an insect repellent containing 30% DEET. Another repellent, permethrin, is meant to be applied to clothing.
After you return from the hike, wash the clothes and place them in a warm dryer. If it’s warm enough, it will kill the ticks.
Check for ticks after you return, shower immediately, and have someone else check places you can’t see, if possible.
The United States Centers for Disease Control and Prevention has more on the Powassan virus.
SOURCES: Eugene Shapiro, MD, professor of pediatrics and epidemiology, vice chair for research, department of pediatrics, and associate director, doctoral program in investigative medicine, Yale University, New Haven, Connecticut; Nicole Baumgarth, DVM, PhD, immunologist, Johns Hopkins School of Public Health, Baltimore; CBS News