What is Powassan? Things you need to know about the virus as more cases are reported

Although cases of Powassan virus disease are still considered rare, health agencies said the number of cases is increasing annually.
Deer tick
Posted at 11:52 AM, Apr 30, 2024

A town in Massachusetts is warning residents to take precautions after its first-ever case of Powassan virus, a tick-borne disease, was reported last week.

Health officials in Sharon, located about 25 miles outside of Boston, announced the confirmed case in a release on April 25 but did not provide information about the infected person or their condition.

Although cases of Powassan virus disease are still considered rare, the Centers for Disease Prevention and Control and other health agencies said the number of cases is increasing annually.

This is what health officials said you should know about the potentially fatal disease caused by the tick-borne virus:

What is Powassan?

Powassan virus (POW) is spread to humans from the bite of infected black-legged deer ticks. It can also come from woodchuck or groundhog ticks, but those cases are less common. The New York Department of Health said the virus is named after Powassan, Ontario, where it was first discovered in 1958.

According to the Massachusetts Department of Health, POW belongs to a group of viruses that can cause infection of the brain or the membranes around the brain and spinal cord.

Although it can come from the same type of infected ticks, POW is different from Lyme disease. Lyme is caused by a bacterium and is the most common vector-borne disease in the U.S., the CDC said.

It is also different from alpha-gal syndrome, which is a severe allergy to a sugar found in meat that can develop from the bite of a lone star tick.

What are the symptoms of Powassan?

Health officials said many people who become infected with POW virus disease do not develop symptoms. But those who do can start to feel ill between one week and four weeks after a bite from an infected tick.

According to the Massachusetts Department of Health, symptoms can include fever, headache, vomiting, weakness, confusion, loss of coordination, speech difficulties and seizures. Severe infections are marked by a quicker onset and include headache, high fever, confusion, tremors, seizures, paralysis, coma or death.

The virus can cause encephalitis and meningitis. The New York Department of Health said half of POW survivors have permanent neurological symptoms, such as recurrent headaches, muscle wasting and memory problems. Approximately 10% of cases are fatal.

While some of the symptoms of POW virus disease are similar to Lyme disease, the CDC said cases of Lyme usually include a rash or swollen lymph nodes.

How is Powassan diagnosed and treated?

According to the New York Department of Health, blood and spinal fluid tests can confirm a case of POW virus after a patient shows symptoms.

Unfortunately, there is no specific medicine to cure or treat POW virus disease. Instead, a health care provider will usually attempt to relieve the symptoms of the illness, officials said.

What precautions should be taken to prevent getting Powassan?

Most cases of POW virus disease have been detected in the Northeastern region of the U.S. and the areas surrounding the Great Lakes. They become more frequent during the late spring, early summer and mid-fall when ticks are most active.

Simply put, the only way to prevent getting infected with POW is to prevent getting bitten by a tick. The more you are outdoors in grassy, wooded areas, the higher the chance you have a tick biting you.

Ticks cannot jump or fly onto a person. They wait in vegetation and cling to humans when they brush by. Experts said to properly remove a tick that is attached to you, grasp the head of the tick with tweezers as close as possible to the attachment site and pull it firmly upward. Try to avoid squeezing or crushing the tick's body since it may contain infectious fluids. Thoroughly disinfect the bite site and wash your hands after removing it.

Here are some tips experts said to keep in mind if you know you will be in a tick-infested habitat:

  • Use an insect repellent that contains DEET.
  • Wear light-colored clothes for easy tick discovery and check frequently for them so you can brush them off before they attach to your skin. Lint rollers can be useful for removing them from clothing.
  • Wear pants and long sleeves, tucking your pants into socks and your shirt into your pants to minimize exposed skin.
  • Check your entire body for ticks when you are back indoors and, if possible, shower immediately to get rid of any ticks that may be present but unattached.
  • If you have pets that are frequently outdoors, consult your veterinarian about tick control options and check your pet over for ticks each time they come back indoors.