County Prepares for Arrival of West Nile Virus

Orange County public health officials say the West Nile virus will reach California in coming weeks -- and they want the public’s help in detecting its arrival.

The Orange County Vector Control District, which combats mosquitoes and other disease-bearing pests, is asking residents to bring any dead birds they find to the district’s lab in Garden Grove or to report them to county animal control officials.

The Orange County district is the only local agency in the state with the ability to test birds for the virus, said Ken August, a spokesman for the California Department of Health Services. Other counties send the birds to a state lab in San Bernardino, to UC Davis or to the U.S. Centers for Disease Control and Prevention in Atlanta.

Michael Hearst, spokesman for the vector control district, said that instead of waiting weeks for results from the state, the county agency’s lab can provide an answer in a day.

West Nile virus is widespread in Africa, East Asia and the Middle East. Since it was detected in the U.S. in 1999 in New York City, the virus has been traveling west. The disease affects birds and mammals. Horses are especially vulnerable, and veterinarians have been encouraging horse owners to inoculate their animals. There is no vaccination for humans.

A common method of transmission is for a mosquito to bite an infected bird and pass the disease to another bird or animal, including humans.

The disease starts in sparrows and finches before moving to crows and then to horses and people, said Jim Webb, the vector control district’s technical director.

The majority of people infected with West Nile show no signs of the disease or they suffer very mild symptoms and never know they’ve had the virus.

The Orange County lab has been working the last three years to modify technology developed by an Australian scientist. The vector control agency also is one of the few local agencies to have a veterinary pathologist on staff, state and county health officials said.

Each test costs $5 to $10.

The Orange County lab has been testing birds found elsewhere in the country for the last two years and comparing its results to those from other labs, such as the one operated by the Centers for Disease Control in Ft. Collins, Colo., to ensure the results are accurate, Webb said.

The agency has tested four or five birds.

Webb said West Nile is expected to arrive within weeks. The disease moves very quickly. In a conference call Thursday, CDC director Dr. Julie Gerberding said tests of mosquitoes in New Jersey the previous week found no evidence of West Nile. The next week, however, every mosquito tested in New Jersey came back positive, she said.

“A couple of weeks ago everybody was kind of complacent, and boom,” Webb said, pointing to the tripling of cases in Colorado within a week.

The only cases of West Nile found in California last year were not thought to have been indigenous. A Los Angeles woman is believed to have been bitten by a mosquito that arrived on a plane operated by an overnight delivery service. A Newport Beach financial planner who contracted the disease said he thought he caught the virus at an outdoor family reunion in Nebraska.

Web said that in Orange County, as much as 60% of mosquito problems come from backyards.

People should take extra care to eliminate places where mosquitoes can breed, he said. They should not allow water to accumulate, especially in rain gutters, wheelbarrows and flower pot saucers.