The West Nile virus has been detected in three mosquito samples collected in Lake County last week. Lake County is now one of at least 24 California counties to report evidence of the potentially fatal mosquito-borne virus in 2024. Many of the cases have been in central and southern parts of the state. So far no human cases have been reported. Sonoma, Napa, Marin and Mendocino counties have not reported the virus this year. Lake County had six human cases last year, including one fatality.