The District collects ticks from around the County and tests for several tick-borne diseases, including Borrelia burgdorferi (which can cause Lyme disease), Anaplasma phagocytophilum (which can cause anaplasmosis), and Borrelia miyamotoi (which can cause a type of tick-borne relapsing fever).

The results of these tests are reported as the minimum infection prevalence, or MIP. This is a way of describing the proportion of ticks tested that are infected with a particular pathogen. MIP is typically reported for each park surveyed (with the exception of parks where there were not enough ticks collected to complete testing), and for the parks as a whole.

A MIP of 2-3% is considered normal for our county, and does not indicate an elevated level of risk.

For more information on how the District collects ticks for disease surveillance, visit the Tick Control and Monitoring page.

The risk of acquiring tick-borne disease in San Mateo County remains relatively low, however, we caution all residents to be careful when walking on trails or in regions with tall grasses. Click HERE to learn more about how to protect yourself from tick bites and the diseases that ticks can spread.