Frequently Asked Questions

What is Powassan virus disease?

Powassan virus disease is a rare, but often severe disease caused by a virus spread to people by infected ticks. The number of reported cases of people sick from Powassan virus has increased in recent years.  Powassan virus belongs to a group of viruses that can cause infection of the brain (encephalitis) or the membranes around the brain and spinal cord (meningitis).

How do people get infected with Powassan virus?

Powassan virus is spread to people primarily by infected ticks. Rarely, Powassan virus has spread person-to-person through a blood transfusion. It does not spread through coughing, sneezing, or touching.

Where and when have most cases of Powassan virus disease occurred?

Most cases have occurred in the northeastern and Great Lakes regions of the United States from the late spring through mid-fall when ticks are most active.

Who is at risk for infection with Powassan virus?

Anyone bitten by a tick in an area where the virus is commonly found can be infected with Powassan virus. The risk is highest for people who live, work or recreate in brushy or wooded areas, because of greater exposure to potentially infected ticks.

How soon do people get sick after getting bitten by an infected tick?

The time from tick bite to feeling sick (incubation period) ranges from 1 week to 1 month.

What are the symptoms of Powassan virus disease?

Many people infected with Powassan virus do not have symptoms. For those who have them, initial symptoms can include:

  • Fever
  • Headache
  • Vomiting
  • Weakness

Powassan virus can cause severe disease, including infections of the brain (encephalitis) or the membranes that surround the brain and spinal cord (meningitis). Symptoms of severe disease can include:

  • Confusion
  • Loss of coordination
  • Difficulty speaking
  • Seizures

How is Powassan virus disease diagnosed?

Healthcare providers diagnose Powassan virus infection based on:

  • Signs and symptoms
  • History of possible exposure to the ticks that spread Powassan virus
  • Laboratory testing of blood or spinal fluid

What is the treatment for Powassan virus disease?

There are no specific medicines to treat Powassan virus disease. People with severe disease often need to be hospitalized to receive support for breathing, staying hydrated, and reducing swelling in the brain.

How can I reduce the chance of getting infected with Powassan virus?

The best way to prevent Powassan virus disease is to protect yourself from tick bites. There is no vaccine to prevent Powassan virus infection. Reduce your risk of getting sick by:

What should I do if I think a family member might have Powassan virus disease?

If you think you or a family member might have Powassan virus disease, see your healthcare provider.