Prophylaxis
Current guidelines do not recommend routine antimicrobial prophylaxis or serologic testing after a tick bite. Although several experts recommend prophylaxis after bites by engorged I. scapularis nymphs, it is very difficult to accurately identify the tick species and assess the degree of engorgement. Testing recovered ticks for B. burgdorferi is not recommended.
People who have been bitten by a tick need close monitoring for development of skin lesions, temperature exceeding 38°C (suggestive of babesiosis or HGE), or other signs of illness for up to 1 month. If illness develops, patients should be evaluated for a tick-borne disease.
Prevention
Despite widespread awareness about Lyme disease, only 40% to 50% of adults take steps to prevent tick bites. Effective strategies include wearing long pants and tucking pant legs into socks. Checking for ticks after time spent outdoors allows prompt detection (within 24-48 hours) and removal before attachment. Ticks are more easily seen on light-colored clothing. Bites typically occur in hidden, moist areas, such as the axilla, groin, or behind the knee and constricted areas such as waistbands. Unfortunately, only 30% of patients even recall a tick bite. Nymphs often occupy the periphery of wooded areas, so following the middle of paths and trails helps minimize contact.
Avoidance of tick-infested areas is an effective but often impractical approach to Lyme disease prevention. Strategies to reduce tick population density include leaf removal and grass cutting. Because tick eggs are deposited on the ground in leaf litter, clearing this reduces the Ixodes population by 72% to 100%; however, the tick population returns within several months. A Massachusetts study demonstrated that mowing grass reduced the tick population by 70%. Seventeen months later, the population remained 53% lower. Large-scale pesticide use is limited by toxicity to plants, birds, and animals.
The use of repellents and toxins is widely recommended. Repellents containing N, N-diethyl-3-methylbenzamide (DEET) are the most effective but must be reapplied often. Permethrin 0.5% fabric spray kills ticks, but skin contact should be avoided. Despite these shortcomings, the benefits of repellents and toxins likely outweigh the risks. The Lyme disease vaccine is no longer available.
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