San Mateo County: Lyme Disease Surveillance

Entomology Report January 2005, San Mateo County Mosquito Abatement District

Surveys for western black-legged tick, Ixodes pacificus, continued through January. This tick is a vector of the Lyme disease bacteria, Borrelia burgdorferi. Adults of this species feed on large mammals such as deer, humans and dogs. They are abundant along recreational trails from November through May. Ticks have been collected at 6 sites thus far. Two out of 147 ticks collected in Los Trancos Woods this year (1%) tested positive for the bacteria.

Tick-Borne Diseases in Santa Cruz County 2003-2004

Annual Report 2003-2004, Santa Cruz County Mosquito and Vector Control District

The County had 8 reported cases of Lyme disease, and one reported case of Rocky Mountain spotted fever in 2003, and 3 reported cases of Lyme disease in 2004 from tick bites. Lyme disease continues to be the most important vector-borne disease in the State, with an average of 200-300 reported cases per year. A recent study by San Jose State University suggested that the infection rate of Ixodes pacificus ticks with Lyme disease in our County may be higher than in other parts of the state, with the number infected averaging 5-6%. This finding was notably higher than previously reported prevalence estimates, although the infection rate in this area is still relatively low compared to that of some east coast states.... Prevention of bites and recognition of symptoms by the public and physicians are the recommended methods of dealing with tick-borne disease.

Ticks and Lyme Disease in Contra Costa County 2004

2004 Annual Report, Contra Costa County Mosquito and Vector Control District

Due to a temporary reduction in our laboratory staff this summer, Lyme disease testing of ticks collected during the 2003/04 field surveillance season is not yet complete.

There were a total of 124 ticks submitted for identification by the public during 2004. Forty-five were identified as the western black-legged tick (the potential vector of Lyme disease). Of these, 11 were tested in-house using the IFA method (one positive) and 28 were submitted to IgeneX Labs for PCR testing (results no longer being reported to the district).