There have been three human cases of West Nile Virus in California this year, with one fatal case, according to the California Department of Public Health.

The Allegheny County Health Department on Monday confirmed that additional mosquito samples have tested positive for West Nile Virus. The health department will treat areas for mosquitoes in the communities of Hazelwood,

San Joaquin County Health officials are encouraging residents to take extra precautions, particularly in the city of Tracy where a significant majority of mosquitoes carrying the West Nile Virus were detected in the area.