Powassan virus cases rise in the U.S., Maine confirms first case

Maine confirmed its first Powassan virus case of 2026 on June 23 in a Penobscot County resident. As of June 16, the Centers for Disease Control and Prevention counted 7 human Powassan cases nationwide across 3 states.

Powassan virus disease is a nationally notifiable condition. It has been reported since 2004 and has been gradually increasing over time in CDC surveillance. A CDC analysis found 64 reported U.S. cases in 2004 through 2013, compared with 270 cases in 2014 through 2023, a four-fold increase. The virus has been identified primarily in the Northeast United States and the Great Lakes region, where people who work or recreate outdoors face the greatest risk.

CDC guidance puts transmission at as little as 15 minutes after an infected tick attaches. There is no vaccine and no specific antiviral treatment, so care is supportive. Symptoms can begin with fever, headache, vomiting, weakness, fatigue and muscle aches, and the infection can progress to neuroinvasive disease, including encephalitis or meningitis. Severe cases can leave lasting neurologic problems or prove fatal.

Maine’s first case this year was not hospitalized, and the person acquired the infection earlier in June. Maine has now logged 41 Powassan cases among residents since 2000. In Rhode Island, health officials confirmed another case on June 26 in a man in his 60s who was hospitalized and later went home. The state’s previous case was in 2024.

Powassan remains rare, yet its range overlaps with the same black-legged ticks that spread Lyme disease, and its rise has been tied in part to that tick expansion. Anyone with fever, headache or other neurologic symptoms after a tick bite should seek medical care quickly, especially in areas where infected ticks are already circulating.