Mosquitoes in a Butler County community have tested positive for West Nile virus. The Mercer County Conservation District says the mosquitoes collected in Franklin Township were the first sample to test positive for the virus in Butler County in 2025.

In the past two weeks, mosquitoes carrying West Nile virus were detected in nine of 12 Staten Island ZIP codes, according to recent trap data.

West Nile virus has been detected in mosquitoes in New York City, but no human cases have been reported in the city so far in 2025.