Cases of the Powassan virus — a rare but potentially fatal tickborne disease that can cause swelling of the brain — are on the rise nationwide.The virus, for which there is no vaccine, hit an all-time high in 2025 with 76 U.S. cases, more than tripling the 24 cases from 4 years earlier, according to CDC data that date to 2004. From 2004-2025, the CDC has recorded 476 total cases, with

Powassan Virus Tick cases: Tick-borne Powassan virus, a rare but dangerous illness, is seeing a surge in US cases, reaching record levels. Unlike Lyme disease, it can transmit in…

Cases of the Powassan virus — a rare but potentially fatal tickborne disease that can cause swelling of the brain — are on the rise nationwide.The virus, for which there is no…