Warm weather encourages millions of people to spend more time outdoors, but it also marks the peak of tick season. While Lyme disease is often the best-known concern, researchers say another, far rarer infection has begun attracting renewed attention.
According to the U.S. Centers for Disease Control and Prevention (CDC), with figures highlighted by Fox News, Powassan virus has been identified in significantly more patients this year than has typically been seen, reports UNILAD.
Although infections remain uncommon, specialists are watching the trend closely because the disease can become severe and there is no targeted treatment.
Different from Lyme disease
One reason the virus has drawn attention is the speed at which it may spread. Unlike Lyme disease, which usually requires a tick to remain attached for many hours before transmission occurs, Powassan virus may be passed on much sooner after a bite.
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Health officials say this makes preventing tick bites especially important, particularly in areas where infected ticks are known to live. Most reported infections have been linked to the Great Lakes region and the northeastern United States.
An unusual increase
Powassan virus was first identified in Canada in 1958 and has long been considered one of North America's rarest tick-borne diseases. However, U.S. surveillance data show 76 confirmed cases during 2025, well above the historical average of roughly seven reported annually.
Not everyone who becomes infected develops symptoms, and illness may not appear until weeks after exposure. When symptoms do occur, they often begin with:
- Fever
- Headache
- Vomiting
- Weakness
In some patients, the infection progresses to inflammation of the brain or surrounding tissues, causing seizures, confusion, speech difficulties and loss of coordination. According to the CDC, about one in ten people who develop severe neurological disease die, while many survivors experience lasting neurological problems.
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No specific cure
Doctors currently treat Powassan virus by managing symptoms rather than eliminating the infection itself. Patients with serious complications may require hospital care, including breathing support, intravenous fluids and treatment to reduce swelling in the brain.
Because there is no vaccine or specific antiviral therapy, public health agencies continue to recommend insect repellent, protective clothing and careful tick checks after spending time in grassy or wooded areas.