Lyme Disease & Tick Testing Posted on August 8, 2025February 27, 2026 The incidence of Lyme Disease in San Mateo County is very low. The microorganism that causes Lyme Disease, Borrelia burgdorferi, is not common among ticks in San Mateo County. Young ticks, or nymphs, are more likely than adults to be infected. The nymphs often clear the infection by the time they reach adulthood. The San Mateo County Mosquito and Vector Control District conducts annual tick collection and testing at popular hiking trails throughout the County. SMCMVCD regularly finds that less than 5% of ticks collected in San Mateo County carry the Lyme disease bacteria. Even if you are bitten by an infected tick, it’s difficult to get Lyme Disease. The tick must be feeding on you for 24 to 48 hours to effectively transfer the microorganism from its stomach to your body. If you find a tick attached to you or your pet, don’t panic. Carefully remove and save the tick. If you would like to have the tick tested, please contact the County of Santa Clara Public Health Laboratory at 408-885-4272 or visit Santa Clara Public Health Lab site for more information. San Mateo County’s Public Health Lab does not offer tick testing.