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:
2026 Service RequestsThe total number of service requests in February was a lower than average (104 requests compared to a five-year average of 155). Requests regarding rodents were particularly less numerous than an average February (27 requests compared to an average of 42). In smaller categories, only three dead birds were submitted for pick up and testing in February, and there was only one tick related service…
2026 Mosquito SurveillanceIn February, adult mosquito counts of all species were very low, which is typical for winter months. Particularly, Culex pipiens, the county’s most abundant mosquito, was well below average this February. We expect to see a seasonal rise in adult mosquito population levels in the spring. The following table and graph show the average number of mosquitoes collected per trap per night during…
