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).

Alameda County Lyme Disease Surveillance, 2003-2004

Annual Report FY 2003-2004, Alameda County Vector Control Services

As part of the Lyme disease surveillance program, staff collect and identify ticks, and may recommend testing for tick borne disease when appropriate. Seventeen field surveys were conducted at nine locations, which resulted in the collection of 1,175 questing ticks of which 651 were Ixodes pacificus, the Lyme disease vector. Three of these ticks were confirmed to be Lyme disease positive by direct immuno-fluorescence (IFA). The three positive ticks represented about 0.046% positive for Lyme disease from the samples taken so far. This number is far below the two percent figure, which is the typical average for endemic Lyme disease areas in California. Alameda County continues to have a low incidence of locally acquired Lyme disease, mainly due to its’ isolated number of suitable habitats for the reservoir and vector. Thirty-seven residents or pets from Alameda County were bitten by ticks. These were submitted to the Sonoma County Public Health Laboratory for Lyme disease testing. All local ticks which bit Alameda County Residents tested negative for the Lyme disease spirochete. The District now has the capability of conducting Lyme disease IFA Tests. We hope to expand this capability when new staff are hired.