Rock County mosquitoes test positive for West Nile Virus

Rock County Public Health said on Wednesday that mosquitoes in the county have tested positive for West Nile virus, the first positive mosquito results in Rock County this year. Mosquito surveillance began in early July. No human cases have been reported in Rock County. The Wisconsin Department of Health Services reported the state’s first confirmed human West Nile virus case of 2025 in Barron County in late July. In 2024, Wisconsin recorded 32 confirmed and probable cases of West Nile virus.