West Nile Virus Detected in Montana

State and local health officials are reporting the first West Nile Virus (WNV) detection of the year in mosquitoes sampled from Blaine County. No humans or horses have tested positive for WNV yet this season.

Infected mosquitoes can transmit WNV when they bite, and the increased risk of WNV transmission to humans and horses is expected to continue through October – or as long as mosquitoes are active in the state.

While no human cases of WNV were reported in 2022, in previous seasons Montana has reported over 50 human cases in a single summer. In 2022, two horses tested positive for WNV, and p...