Powassan Virus: Causes, Symptoms, Diagnosis & Treatment Explained

Powassan virus disease is a rare illness that you can get from tick bites. It usually causes mild symptoms, but it can spread to your brain and cause severe illness (encephalitis). Symptoms of severe infection include confusion, seizures and difficulty speaking. It’s found in the U.S. Northeast and the Great Lakes region of the U.S and Canada.

Overview

Powassan virus disease is an illness you get from a tick bite. Many people have Powassan virus without any symptoms, but sometimes it causes Powassan virus encephalitis. Encephalitis is brain swelling that can lead to permanent neurological conditions, like memory issues and paralysis. In some cases, it can be fatal. Powassan virus is named after Powassan, Ontario, the area of Canada where the first case was identified in 1958.

Symptoms and Causes

What are the symptoms of Powassan virus disease? Symptoms of a Powassan virus infection include:

Fever.
Headache.
Vomiting.
Fatigue.
Confusion or altered mental state.
Seizures.
Difficulty speaking.
Paralysis.

Common symptoms, like fever and headache, might come first, followed by more severe symptoms, like confusion or seizures.

What’s the incubation period for Powassan virus?

The incubation period for Powassan virus disease is between one week and one month. This means from the time an infected tick bites you, it usually takes one to four weeks to have symptoms.

What causes Powassan virus disease?

A type of flavivirus (an RNA virus usually spread by mosquitoes and ticks) causes Powassan virus infections. The viruses that cause dengue fever, West Nile and Zika infections are also types of flavivirus.

How does Powassan virus spread?

You get Powassan virus from the bite of an infected Ixodes tick. Ixodes scapularis, commonly called blacklegged or deer ticks, are the most likely to spread it to people. Ixodes cookei (groundhog tick) and Ixodes marxi (squirrel tick) also carry Powassan virus, but they rarely bite people. Unlike some other tick-borne illnesses, a tick only needs to attach to you for a few minutes to infect you with Powassan virus.

Where is Powassan virus found? Powassan virus infections happen most often in parts of Russia, the U.S. Northeast, and the Great Lakes region in the U.S. and Canada.

Management and Treatment

There is no specific treatment for Powassan virus disease. Treatment focuses on relieving symptoms while your immune system fights off the infection. If you have severe symptoms or complications from encephalitis, you may need hospitalization.

Prevention

The best way to prevent Powassan virus disease is to avoid tick bites:

Wear long-sleeved shirts and pants when you’re outside.
Use insect repellent that contains DEET or permethrin.
Check yourself for ticks after being outside.
Remove ticks as soon as possible if you find them on your skin.

Tick-Borne Diseases

Tick-borne diseases are illnesses caused by pathogens transmitted by ticks. They are becoming more common in many parts of the world due to climate change and other factors.

Overview

Ticks are small arachnids that feed on blood. They can transmit bacteria, viruses or parasites that cause diseases in humans and animals. Some common tick-borne diseases include Lyme disease, Rocky Mountain spotted fever and babesiosis.

Symptoms and Causes

What are the symptoms of tick-borne diseases? Symptoms vary depending on the type of pathogen involved but may include:

Fever.
Headache.
Muscle aches.
Rash.
Fatigue.
Joint pain.
Nausea or vomiting.

What causes tick-borne diseases?

Tick-borne diseases are caused by pathogens transmitted by ticks. These pathogens can be bacteria (like Borrelia burgdorferi which causes Lyme disease), viruses (like Crimean-Congo hemorrhagic fever), or parasites (like Babesia microti which causes babesiosis).

How do ticks transmit diseases?

Ticks transmit pathogens when they bite humans or animals to feed on their blood. The pathogens enter the bloodstream through the tick’s saliva.

Management and Treatment

Treatment for tick-borne diseases depends on the type of pathogen involved but may include antibiotics or antiviral medications. In some cases, hospitalization may be necessary.