Alameda County: Tularemia Surveillance 2006-2007

Annual Report 2006-2007, Alameda County Vector Control Services

Tularemia is caused by the bacterium Francisella tularensis that infects a variety of arthropods and vertebrates. Symptoms of human tularemia may include fever, chills, malaise, and fatigue. The disease is commonly transmitted by contacts with rabbits, insects, or tick bites. In Alameda County, a confirmed human case, transmitted by an American dog tick, Dermacentor variabilis was reported by CDHS in 2004. Since tularemia is classified as a bio-terrorism agent, the CDHS requested blood samples from various animals for testing. In 2006, 12 rodent samples were submitted; results are still pending.

Alameda County: Lyme Disease Surveillance 2006-2007

Annual Report 2006-2007, Alameda County Vector Control Services

As part of the Lyme disease surveillance program, our staff collects and identifies ticks, and recommends testing for tick borne disease when deemed appropriate. Our District provides consultations, educational resources, tick identification, and testing facilities for Lyme disease. Fifteen Ixodes pacificus ticks were submitted to the Sonoma County Public Health Laboratory for Lyme disease testing; all tested negative. The District now has the capability to perform Lyme disease indirect fluorescent antibody (IFA) tests. We hope to expand this capability when new staff is hired.

Reported Cases of Tularemia in California 2004

Annual Report 2005, Alameda County Vector Control Services

Tularemia, a diseased caused by strains of Francisella tularensis, is not commonly transmitted by contacting rodents or tick bites. However, three human cases of tularemia were reported to CDHS in 2004; two of which were likely acquired through a tick bite: one from Alameda County and one from Contra Costa County. The adult American dog tick (Dermacentor variabilis) removed from the Alameda case was tested positive by culture and PCR for F. tularensis (type B) by Center for Disease Control and Prevention (CDC). Because of the human cases and also its importance as a bioterrorism agent, the CDHS requested blood samples from various animals for testing. Blood samples from twenty-three rodents from various locations in Alameda County were submitted for testing. None of these samples showed infection with F. tularensis. United State Department of Agriculture (USDA) – Animal and Plant Health Inspection Service (APHIS) submitted additional twenty-eight blood samples of feral cats, skunks, Norway rats, jackrabbits and red foxes. Of these, one striped skunk tested positive for the tularemia pathogen.

Alameda County Lyme Disease Surveillance, 2004-2005

Annual Report FY 2004-2005, 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. Field surveys were conducted at seven locations, which resulted in the collection of 446 questing ticks of which 439 were Ixodes pacificus, the Lyme disease vector. None of these ticks were confirmed to be Lyme disease positive by direct immunofluorescence (IFA). Forty four residents or pets from Alameda County were bitten by ticks. These were submitted to the Sonoma County Public Health Laboratory for Lyme disease testing. One local ticks which bit Alameda County Residents tested positive 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.

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.

Alameda County Lyme Disease Surveillance, 2002-2003

Annual Report FY 2002-2003, 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 capture of 182 adult Ixodes pacificus ticks. Three of these ticks were confirmed to be Lyme disease positive by direct immuno-fluorescence (IFA). The three positive ticks represented about 1.6% positive for Lyme disease from the samples taken so far. This number is slightly 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.

Twenty-seven residents of Alameda County were bitten by ticks, and submitted them to the Sonoma County Public Health Laboratory for Lyme disease testing. All of the twenty-seven ticks acquired in Alameda County tested negative for the Lyme disease spirochete. Two Lyme disease case histories from the previous year were completed in 2002. The areas where these victims had frequented were surveyed several times, but none of the tick samples yielded positive results for the Lyme disease spirochete, Borrelia burgdorferi.

Alameda County Lyme Disease Surveillance, 2001-2002

Annual Report 2001-2002, Alameda County Vector Control Services

As part of the Lyme disease surveillance program, District Staff identify ticks and mites, and will authorize testing for tick borne disease when appropriate. The District is currently investigating two human Lyme disease, case histories, from victims who are believed to have acquired the disease in Alameda County. The collections and surveillance will occur in the spring of 2002, when the adult and nymphal Ixodes pacificus ticks are most numerous. As part of the general tick borne disease surveillance program, 49 Western Black Legged Ticks were tested and none were positive for Borrelia burgdorferi. Vector control officers are being trained in tick surveillance techniques and equipment, and plans are in place to increase tick surveillance. Sixty-Five residents of Alameda County were bitten by ticks, and submitted them to the Alameda County Public Health Laboratory for Lyme disease testing. Some additional samples were sent to IgeneX, a private laboratory for PCR Testing. All of the twenty-four ticks acquired in Alameda County tested negative for the Lyme disease spirochete. Additional ticks, one from France and another from the east coast, tested positive for Borrelia burgdorferi, the bacteria responsible for Lyme disease.

Alameda County Lyme Disease Surveillance, 2000-2001

Annual Report FY 2000-2001, Alameda County Vector Control Services

The district will identify ticks and mites, and will authorize testing for tick borne disease when appropriate. Fifty-seven residents of Alameda County were bitten by ticks, and submitted them to the Alameda County Public Health Laboratory for Lyme disease testing. Some additional samples were sent to IgeneX, a private laboratory for PCR Testing. One of the Ixodes pacificus ticks tested positive for Borrelia burgdorferi, the bacteria responsible for Lyme disease.

Sunol / Ohlone Regional Park
Staff conducted a tick survey at Sunol/Ohlone Regional Park in April of 2000, in response to a report of a confirmed case of Lyme disease by a visitor to the park. Twenty-five Western Black Legged Ticks, Ixodes pacificus, were collected and submitted to the Alameda County Public Health laboratory for testing. One of the tick pools, containing about 5 ticks, tested positive for Borrelia burgdorferi, the spirochete responsible for Lyme Disease.