The Southern Nevada Health District has detected its first West Nile virus-positive mosquitoes of 2025, officials said this afternoon.

West Nile virus is usually spread through the bite of an infected mosquito during the summer and fall. Your best bet to avoid the virus is to avoid mosquito bites when possible.

Four mosquito pools have tested positive for West Nile, including three in Lewis and Clark County and one in Cascade County. Additionally, Sheridan, Custer, and Daniels Counties have each reported one confirmed case of the virus in horses, totaling three positive horses in Montana so far this season.