Protection From Lyme Disease

PROTECTION FROM LYME DISEASE

Many Californians are concerned about Lyme Disease, which is caused by a spirochete (corkscrew-shaped bacterium) that is transmitted by the bite of an infected tick. Fortunately, only low percentages of a single species of tick (Western Black-legged tick) that is known to transmit the disease to people in California contain spirochetes. Moreover, hikers or other outdoor enthusiasts who follow a few common sense guidelines are not likely to pick up the disease in this State.

LYME DISEASE
Named after Lyme, Connecticut, where it was first recognized in the mid-1970’s, the disease has been reported in 43 states within the US, many European countries, and many countries on other continents including China, Japan, Australia, and the USSR. The disease was first reported in California in 1978. Although surveillance for Lyme Disease by State health authorities was initiated in 1983, it did not become officially reportable in California until 1989.

The disease can usually be cured with antibiotics such as tetracycline or penicillin within the first few weeks of infection. If untreated soon after onset of symptoms, however, arthritic, cardiac or neurologic abnormalities may develop weeks or months later, and the disease may be more difficult to cure. Since there is no vaccine against the disease, the best preventive measure is to avoid being bitten by ticks, especially the Western Black-legged tick.

SYMPTOMS
The disease in humans often begins with a slowly expanding circular rash 3 to 32 days following the bite of an infected tick. The rash, which usually originates at the point of tick attachment and occurs in up to 60 to 80 percent of patients, may reach a diameter of several inches. Typically, the primary rash has a bright red outer margin and exhibits partial central clearing, but in 20 to 40 percent of patients it is atypical or does not develop at all. Subsequent rings may appear elsewhere on the body in up to nearly one-half of patients. Many patients also experience fatigue, headache, fever, chills and other flu-like symptoms during the initial stage.

During the second stage, which occurs several weeks to a few months after the bite, patients may develop various neurological or heart abnormalities as well as an intermittent arthritis.

During the third stage, which begins months or years after the bite, it may manifest itself as chronic or intermittent arthritis in approximately 60 percent of untreated patients, neurological complications (e.g. memory defects, personality changes, profound fatigue), and occasionally even further dermatological abnormalities. Dogs, horses, cows and other animals also are susceptible to Lyme disease. They may develop arthritis or lameness, lethargy, loss of appetite, disease of the Lymph nodes, or other conditions following infection.

WESTERN BLACK-LEGGED TICK
In California, the spirochete causing Lyme disease has been detected in or isolated from several species of ticks, but the Western Black-legged tick, Ixodes pacificus, appears to be the primary transmitter to people. This tick feeds on about 80 different species of lizards, birds and mammals. An adult tick may lie in wait on vegetation for hours or even days for a potential host to brush against it. After grasping a suitable host (e.g. a deer) the tick eventually attaches to the skin of the host with its mouthparts to secure a blood meal.

PROTECTION FROM TICKS
Humans and other animals are most apt to encounter ticks in grassy or brushy areas and on the margins of trails in parklands and wildlands. When stopping to rest, people and other animals also may pick up immature ticks directly from soil or leaf litter. Follow these guidelines to protect yourself against ticks and the disease agents they transmit:

Wear full-length trousers and shirts when recreating or working outdoors in tick-infested areas; light-colored clothing is preferable since dark-bodied ticks are easier to spot against a light-colored background.
Tuck blouses or shirts into pants, and pant legs into boots or beneath socks.
Check your clothing and exposed skin for presence of tick at least hourly. Also, check your pets after they have been outdoors since infested animals may transport potentially infected ticks directly into the home environment.
Ticks may attach to humans almost anywhere on the body, but those that bite fully-clothed persons commonly attach to such sites as the scalp, behind the ears, or on a limb. Therefore, pay particular attention to these areas while checking yourself or others for ticks.
Spray clothing or skin with tick repellents registered for use against ticks according to the manufacturer’ instructions. After swimming or perspiring heavily, reapply those repellents that can be applied to skin.
To protect your pets, use tick collars or other forms of pesticides (e.g. dust, sprays) that are commercially available for controlling ticks on dogs or cats.
After outings, recheck your clothing and skin (and those of your children) for ticks, then bathe or shower and wash your clothing, if possible.

TICK REMOVAL
Remove an attached tick immediately. Prompt removal may prevent disease transmission from an infected tick. It usually takes several hours to a day or longer for an attached infected tick to transmit the Lyme disease agent.

To remove an attached tick, grasp its mouthparts as close to the skin as possible with a pair of tweezers. If tweezers are unavailable, remove the tick with fingers protected by tissue paper. Do not squash the tick; if an infected tick is crushed or squeezed with bare fingers, spirochetes present in tick fluids may penetrate the unbroken skin or they may be transmitted mechanically into the bite-wound.

Pull the tick straight out, slowly and steadily. Remove mouthparts that break off in the skin promptly (consult a physician, if necessary). The mouthparts may contain other bacteria that can cause a painful secondary infection.

Do not jerk or twist the tick. Do not apply alcohol, fingernail polish, heat (e.g. with a lit match) or petroleum jelly to it; these methods have been shown to be completely ineffective, and application of heat may actually induce a tick to regurgitate its midgut contents or secret saliva into the bite-wound along with any disease agents that it may be carrying.

Clean the wound with soap and water, and apply a mild antiseptic such as povidone-iodine, if available. Save all ticks that have been removed from humans for identification in case the person bitten becomes ill within one month after discover of the tick.

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