Lyme disease

Ixodes pacificus ticks tested for evidence of Borrelia species, California, 2008.

The following table contains the results of tests for evidence of Borrelia infection in ticks collected in California in 2008. The tests were conducted by the California Department of Public Health, Vector-Borne Disease Section (CDPH-VBDS), and by the United States Army Center for Health Promotion and Preventive Medicine - West (US Army).

Lyme disease

Lyme disease is a tickborne disease caused by the bacteria Borrelia burgdorferi.  It was first identified in California in 1978 from a Sonoma County hiker.  While incidence of Lyme disease (number of cases adjusted per population) is highest in the northwestern part of the state, human cases have been reported from many regions of California.