West Nile Virus SurveillanceThe District’s West Nile virus surveillance program reports several types of positive West Nile virus results, including dead birds, mosquito samples (“pools”), sentinel chickens, and human cases.
Tick-borne disease pathogens in San Mateo CountyOver the past several years, staff have collected more than 30,000 ticks from around the County. Our laboratory staff identify and test these ticks for:
2025 Service RequestsOur staff were very busy helping with a variety of services, including mosquitoes, rodents, and ticks.
2025 Mosquito SurveillanceIn September, adult mosquito counts remained low except for the species Culex pipiens, which rose to its highest level this year.
