West Nile Virus On The Rise In Montana

DPHHS urges Montanans to take extra care to avoid mosquito bites this summer

State and local health officials are reporting increased West Nile virus (WNV) activity in several counties across the state this week, including the first three human cases for 2023, which have been identified in Dawson, Rosebud, and Yellowstone counties.

These three cases range in ages from the late 30s to early 70s, including two males and one female. All cases were hospitalized for their illnesses. Additionally, this week, two horses were diagnosed with WNV infections in Hill and Pondera counties. Mosquito pools also tested positive for WNV in Glacier, Lewis and Clark, and Toole counties.

Earlier this summer, mosquito pools tested positive in Blaine, Hill, and Phillips counties.

WNV infections can occur in humans or horses after a bite from an infected Culex mosquito. Increased risk of WNV transmission to humans and horses is expected to continue through Octobe...