Mosquitoes Test Positive for West Nile Virus in Knightsen, California

Knightsen, California – This summer, the first mosquitoes to test positive for West Nile virus have been found in Contra Costa County. Officials announced the discovery on Thursday following testing of a group of mosquitoes collected from a trap in Knightsen.

Two weeks prior, a California scrub jay in San Ramon also tested positive for the virus, marking the first bird case in the county this year. According to the California Department of Public Health, nearby counties including Alameda, Santa Clara, and San Joaquin have reported infected birds this summer.

Statewide, there have been seven reported human cases of West Nile virus this year, which includes one fatality in Tulare County. Last summer, a man from east Contra Costa County died from West Nile virus, marking the first reported death in the county since 2006.

Steve Schutz, the scientific program manager for the Contra Costa Mosquito and Vector Control District, emphasized the importance of taking preventive measures to avoid mosquito bites. He recommended using EPA-registered insect repellents with active ingredients such as DEET or Picaridin to reduce risks.

Public health officials also noted that mosquitoes primarily acquire West Nile virus from birds. They encourage residents to report any dead birds as part of the surveillance effort to track the virus’s spread. Dead birds can be reported at (877) 968-2473 or through their online portal.

For additional concerns about mosquitoes or to ask questions, residents can contact the District at (925) 685-9301 or visit their website for more information.