Hikers and other outdoor enthusiasts should not panic over last week's discovery that a tick found in the Topanga area tested positive for the bacterium that causes Lyme disease, county officials say. Instead, they should practice preventive measures and educate themselves about symptoms of the disease, a bacterial infection transmitted by the Western black-legged tick here or deer ticks elsewhere.
The tick that tested positive, the first in Los Angeles County, was retrieved from a hiker who was bitten in Topanga State Park and probably originated either in the park or at the hiker's home about a mile away, says Robert Saviskas, executive director of the Los Angeles County West Vector Control District, which announced the finding.
L.A. County has not been considered a high-risk area for Lyme disease, which is highly treatable with antibiotics if caught early but can lead to chronic, severe problems such as arthritis or nervous system disorders if left untreated. Death from Lyme disease is rare. Officials are continuing to collect ticks for evidence of Lyme disease, say Saviskas and Dr. Roshan Reporter, a physician in the county Department of Health Services.
Meanwhile, hikers are advised to wear light clothes so ticks can be seen, spray clothing with tick repellent and tuck pants into boots.
When back indoors, check your skin, advised Dr. Alan Barbour, UC Irvine professor of medicine and microbiology and Lyme disease expert. Favored spots include the backs of the ears, backs of the knees, groin, belt line, underarms, back of the neck and the navel. "These ticks are very small--about the size of a sesame seed, but black," Barbour says. In 70% to 90% of cases, he says, a flat, circular bull's-eye skin rash appears around the bitten area. There can also be flu-like symptoms.
Prompt tick removal can reduce the risk of catching the disease. Use a fine-pointed tweezer to grasp the tick around its mouth parts. Save it for testing by placing it in a sandwich bag with a moistened bit of paper towel. Swab the bitten area with rubbing alcohol. Call a doctor. Blood tests to detect antibodies to the bacterium can be done. Call the county's tick hotline, (310) 915-7370, Ext. 505, for tick pickup.
Exactly how long a tick must be embedded to transmit the disease is debated by experts. County officials say 12 to 24 hours are needed; Barbour says the tick must usually be embedded for a couple of days before transmission. And Nick Harris, president of the Palo Alto, Calif., lab that ran the DNA test on the infected tick, says more study is needed.
Vaccines are expected on the market soon. SmithKline Beecham has asked the Food and Drug Administration to approve its LYMErix. And Pasteur Merieux Connaught plans to ask this year for FDA approval for its ImuLyme vaccine.
* For more information, call the American Lyme Disease Foundation, (800) 876-LYME, or the Lyme Disease Foundation, (800) 886-LYME.