- Powassan virus is carried by deer ticks and can be transmitted to humans through tick bites.
- While Powassan virus disease is rare, a few cases have made headlines in recent weeks.
- Most people who contract the virus don’t have symptoms, but in rare cases, it can cause encephalitis and meningitis.
Maryland reported the state’s first death related to the Powassan virus on October 6. Health department officials said they believe the person contracted the virus while on a trip to Canada.
Powassan virus is a rare deer tick-borne infection that usually does not cause serious harm.
In rare cases, however, Powassan virus could lead to encephalitis (an infection of the brain) or meningitis (infection of the membranes around the brain and spinal cord).
Powassan virus cases have been increasing in the United States in recent years. In 2022, 44 cases of Powassan virus were reported, marking the highest number of cases on record, according to the
In 2023, 28 Powassan virus cases have been reported so far.
Most Powassan virus cases are found in the regions where deer are most abundant. This includes the Northeast and the Great Lakes regions in the U.S., typically from spring through fall.
The Powassan virus and Lyme disease are carried by deer ticks and transmitted to humans via tick bites, but the comparison stops there.
“Powassan virus is a virus, as the name implies. Lyme disease is [caused by] bacteria,” Dr. David Goldberg, an infectious disease specialist at New York-Presbyterian, told Healthline in a 2021 interview.
“They are completely different organisms. The [other] main difference is that Powassan is extremely rare,” Goldberg explained.
Lyme disease is much more prevalent. According to the CDC, approximately
This is far more than the number of Powassan cases detected in the U.S.
In the past 20 years, the number of Powassan cases detected annually has ranged from as low as a single case in 2004 to 44 cases in 2022, according to the
Since Lyme disease is a bacterial infection, antibiotic options exist to treat it. There is currently no treatment for the Powassan virus and no vaccine.
The incubation period for the Powassan virus can range from 1 week to 1 month. Those who show symptoms may experience:
- fever
- headache
- vomiting
- weakness
In extreme cases where people develop encephalitis or meningitis, symptoms of infection may include:
- confusion
- loss of coordination
- difficulty speaking
- seizures
“Sometimes, post-encephalitis, people can have lingering neurologic symptoms, which can be variable. Some can be memory loss, persistent confusion, loss of balance, hearing loss,” Dr. Nima Majlesi, director of medical toxicology at Staten Island University Hospital, told Healthline in a 2021 interview.
“If someone has signs of encephalitis and it is the right time of year and in the right part of the country, you can test the blood and spinal fluid for evidence of the virus, but really, there is no other way to tell. There probably are many more cases that we don’t know about that are milder,” Goldberg said.
If you see a tick embedded in your skin and are unsure how long it’s been there, or you cannot fully remove it yourself, call a healthcare professional for guidance.
One of the most important things to remember is that Powassan virus disease is rare. So, while it is always good to be cautious and take preventive measures, it does not mean you must stay indoors.
“Avoid the over-fear,” said Majlesi. “We’re talking about a disease that is extremely rare. If you take these preventive measures, you have a very low likelihood [of contracting the virus]. Enjoy yourself. Be outside, be active, and be educated.”
Still, anyone exposed to a tick bite in the parts of the country where the Powassan virus occurs could be at risk.
You may be at a higher risk if your job or daily life often has you outside in wooded areas. There is no demographic that is more at risk than others.
You can practice the same precautionary measures that you do with all tick bites to prevent exposure to Powassan virus.
“Prevention is about surveillance,” said Majlesi. “There are a lot of ways to prevent tick bites. It’s multi-factorial.” Some prevention measures include:
- wearing long pants in wooded areas
- spraying your body or clothes with permethrin
- showering immediately after being outdoors
- doing a full body check after coming in from outdoors
Tick bites are relatively common in large areas of the U.S.
If you’re spending time outdoors where you may be exposed to ticks, it’s important to do a
If you find that a tick has bitten you and is embedded in your skin, the CDC recommends the following:
- Use tweezers to pull the tick out using steady, even pressure.
- Pull the tick upward without jerking or twisting it.
- After removing the tick, wash the affected area with soap and water, rubbing alcohol, or an iodine scrub.