Powassan virus cases hit US record of 76

A rare and potentially fatal tick-borne virus is reaching record levels in the United States, with public health officials reporting a sharp increase in cases. The Powassan virus, transmitted by deer ticks and woodchuck ticks, infected 76 Americans in 2025, according to data from the Centers for Disease Control and Prevention. This marks the highest annual total on record and a dramatic rise from the historical average of seven to eight cases per year.

The virus, named for Powassan, Ontario, where it was first identified in 1958 following the death of a young boy, is considered particularly dangerous due to its rapid transmission. While Lyme disease typically requires a tick to be attached for 36 to 48 hours, an infected tick can transmit the Powassan virus in as little as 15 minutes, according to Dr. Jorge P. Parada, a medical advisor at the National Pest Management Association.

Most people infected with Powassan virus show no symptoms. For those who do, early signs appear one to four weeks after a bite and include fever, headache, vomiting, and weakness. In severe cases, the virus can invade the central nervous system, causing encephalitis or meningitis. This can lead to...