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What is Powassan Virus, the Untreatable and Sometimes Deadly Tick-Borne Disease?

June 17, 2021

The blacklegged tick, otherwise known as the deer tick, is a multiple-threat arachnid. Humans, especially those in Connecticut, know it as a carrier of the bacteria that causes Lyme disease.

But the state Department of Public Health this week identified the year’s first two cases of Powassan virus, an untreatable disease that can cause brain inflammation (encephalitis), transmitted by an infected blacklegged tick. Half of Powassan virus patients endure permanent neurological problems. Two people died among the 10 cases in Connecticut between 2016 and 2020

“It’s ironic that Lyme disease gets all the press, but there are scarier diseases you can get from these ticks,” says Dr. Ulysses Wu, Hartford HealthCare’s System Director of Infection Disease and Chief Epidemiologist.

DPH said the residents, between 50 and 79 years old who live in Fairfield and New Haven, were hospitalized in late April. Lab tests confirmed they were infected with Powassan.

Symptoms of Powassan Virus

These are possible initial symptoms, according to The Centers for Disease Control and Prevention:

  • Fever.
  • Headache.
  • Vomiting.
  • Weakness.

Severe illness, which can include either encephalitis or infection of the membranes around the brain and spinal cord (meningitis), might include these symptoms:

  • Confusion.
  • Loss of coordination.
  • Difficulty speaking.
  • Seizures.

“There are some types of encephalitis that can result in body twitching and muscle twitching,” says Dr. Wu. “Even eyelid-twitching has been reported.”

There’s no specific cure for Powassan, named after a town in Ontario where the virus was first identified in 1958, but severe cases often require hospitalization, intravenous fluids and respiratory support. The disease remains rare, even as cases increase. Until 2016, the reported cases in the United States did not exceed 12 in any year. In 2019, the latest available data from the CDC, health officials reported 39 cases nationally.

An infected tick needs as little as 15 minutes attached to your  body to transmit the Powassan virus. If that same tick were infected with Lyme disease, it would take up to two days attached to your body to transmit.

Symptoms of Lyme Disease

A rash often appears from three to 30 days after the bite, expanding up to 12 inches. It may or may not develop into a bull’s-eye pattern. But be careful: Up to 30 percent of people infected with Lyme disease do not get a rash. Other symptoms might resemble the flu: Fever, chills, headache and body aches. Check with your doctor as soon as possible.

Symptoms of chronic Lyme disease also often mimic chronic fatigue syndrome, fibromyalgia and juvenile idiopathic arthritis.

Last year, 50 percent of tested ticks in the state were infected with either Lyme disease (40 percent) or two other tick-borne diseases, anaplasmosis (10 percent) and babesiosis (10 percent), according to the Connecticut Agricultural Experiment Station in New Haven. More than 5 percent were infected with two of the diseases. Two percent were infected with all three.

Days before the Powassan cases were announced, Sen. Richard Blumenthal appeared at the CAES in New Haven to urge additional federal funding directed to Lyme disease and other tick-borne illnesses.

What You Should Know

Q: What’s the best way to prevent a tick bite?
 Wear long pants, long sleeves and light-colored clothing, which makes it easier to detect ticks. Spray exposed skin with a repellant that contains up to 30 percent DEET. A permethrin (0.5 percent) spray works best on clothing, shoes, sneakers and other gear.

Ticks attached to clothing can survive machine washing. To kill any ticks, tumble-dry clothes on high heat for 10 minutes. If the clothes must be washed first, use hot water.

Q: How should I remove a tick embedded in my skin?
 The CDC recommends fine-tipped tweezers.

  • Grasp the tick close to the skin.
  • Pull steadily, with even pressure. A twist or other sudden movement could cause the tick’s mouth parts to break off and remain in the skin.
  • After removal, clean the area thoroughly with rubbing alcohol, iodine or soap and water.