Powassan Virus: What You Need to Know

What Is Powassan Virus? 

Powassan (POW) virus is a rare but serious illness spread through tick bites. It belongs to the same virus family as West Nile, but unlike West Nile, which mosquitoes carry, Powassan is tick-borne. The virus gets its name from Powassan, Ontario, where the first known human case was found back in 1958. 

How Do You Get It? 

Powassan virus is spread via the bite of an infected tick. Three types of ticks can spread it, and they're mostly found in the eastern half of the U.S.: 

The blacklegged tick is the main concern because it commonly bites people. It also carries Lyme disease, anaplasmosis, and babesiosis. So a single tick bite can potentially transmit more than one infection. 

Ticks like to hide in hard-to-spot places, think your groin, armpits and scalp. So always do a full-body check after spending time outside. 

Symptoms to Watch For 

Here's what makes Powassan especially tricky: the tick doesn't need to be attached for long. While Lyme disease requires a tick to feed for 24–48 hours before it can infect you, Powassan can be passed in as little as 15 minutes. Most people don't even remember being bitten because the tick is tiny and easy to miss. 

Symptoms usually show up 1–3 weeks after a bite and can include: 

In serious cases, the virus can cause swelling of the brain or the tissue around it. That can lead to a stiff neck, trouble speaking, numbness and even facial paralysis. These are medical emergencies, so if you or someone you know shows these signs after a tick bite, get to the emergency room right away. 

Powassan tends to affect young children and older adults the hardest, so those groups should be especially careful, especially during peak tick season. 

How Serious Is It? 

Very. 10–15% of severe Powassan cases are fatal. And for those who survive a serious infection, about half will deal with lasting neurological issues, things like chronic headaches, paralysis, muscle weakness and memory problems. 

Cases have been climbing. The U.S. now sees 50 to 60 reported cases every year, with hundreds of total cases on record. Most happen in the Northeast and Great Lakes regions, and the bulk of infections occur between June and September when ticks are most active. 

Is There a Treatment? 

There's no specific cure or vaccine for Powassan virus. Severe cases usually mean a hospital stay, where doctors can provide: 

How to Protect Yourself 

Since there's no vaccine, your best move is to not get bitten in the first place. Here's what helps keep ticks at bay: 

A licensed pest control professional can help remove rodents and wildlife from your property, and provide treatments to control and prevent ticks as part of a comprehensive pest management program.