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What Is Powassan Virus?

I heard about some new tick-related infection called Powassan virus. What is it and should I be worried about it?
– Sally

Powassan (POW) virus can spread to humans through the bite of an infected tick, as Lyme disease does. It's not actually new (it was discovered in Powassan, Ontario, in 1958), but because it's very rare, many people are just starting to hear about it.

Only 75 cases have been reported in the United States in the last 10 years, mostly in the northeastern and Great Lakes regions.

Although POW infections are very rare, they can be serious and may cause:

  • fever
  • headache
  • seizures
  • vomiting
  • weakness and confusion
  • memory loss
  • meningitis (inflammation of the membranes that cover the brain and spinal cord)
  • encephalitis (swelling of the brain)

There's no cure, and someone with a severe Powassan virus infection might need treatment in a hospital that includes respiratory support, IV fluids, or medicines to ease brain swelling.

As with other more common tickborne illnesses, these outdoor precautions can help protect you and your kids from POW:

  • Wear closed shoes or boots, long-sleeved shirts, and long pants.
  • Tuck pants into shoes or boots to prevent ticks from crawling up your legs.
  • Wear light-colored clothing to help you see ticks easily.
  • Keep long hair pulled back or wear a hat for added protection.
  • When outside, don't sit on the ground.
  • Use an insect repellent containing 10% to 30% DEET (N,N-diethyl-meta-toluamide).
  • While outdoors, check your family for ticks often. Check again after you go back inside (don't forget to check pets too).

Also, be sure you know how to remove a tick, just in case.

Reviewed by: Kate M. Cronan, MD
Date Reviewed: 10-05-2017

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