Wilderness and Rescue Medicine 8th Edition

Wilderness and Rescue Medicine 186

Vaseline, alcohol, gasoline, or mineral oil. These tactics may cause the tick to regurgitate infectious material into the bite. Do not handle the tick with- out gloves or other protection. Prompt removal of ticks can also help reduce the transmission of disease. Lyme disease, for example, is not effectively transmitted until the tick has been in place for a day or so. Rocky Mountain spotted fever can be transmitted in just a few hours. In regions where Lyme disease is endemic, medical practitioners will often prescribe a single- dose treatment of doxycycline or other antibiotic to patients who have suffered a prolonged tick attachment. Tick country is vegetated with woods, grass, and brush. Tick season is spring, summer, and fall. Adult ticks are eight-legged arthropods ranging in size from nearly microscopic to a centimeter in diameter. The ticks of greatest concern, for Lyme disease at least, are two to four millimeters in diameter, and before they begin to feed are not easily recognized as a foreign creature on your skin.

travel in a tick-infested area is worth immediate medical evaluation for several tick-borne illnesses. Mosquitoes The list of diseases transmitted by mosquitoes includes malaria, filariasis, West Nile virus, equine encephalitis, dengue fever, and a host of others. The key to avoiding these infections is to avoid being a host to mosquitoes. Like ticks, they can be deterred by insect repellent and tight-weave clothing. Unlike ticks, they can transmit disease in less than a minute. Prophylactic medication with atovaquone/pro- guanil, doxycycline or others can help prevent malaria infection. However, some diseases, such as filariasis, have no definitive cure and no effec- tive prophylactic medication. The fewer mosqui- toes you feed, the less your chance of becoming ill.

Mosquito-borne Disease

General Principles

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Prevention: • DEET, Picaridin, IR3535 or Lemon/Eucalyptus* on skin • Permethrin on clothing • Tight - weave clothing • Avoid feeding time • Pre- or post-exposure prophylaxis in Malaria endemic regions**

*

* not against malaria ** see www.cdc.gov

© 2018 WMA

The same clothing and repellent tactics used with ticks apply well here. In addition, avoid being exposed during the times of day when vec- tor mosquitoes feed. This is typically dawn and dusk but may be a few hours during the middle of the night depending on location. Permethrin- impregnated bed nets have been very successful in some places, but some mosquito populations have changed their feeding time behavior, possibly in response to the nighttime use of bed nets. Local knowledge may help with your prevention plan. Fleas, Lice, and Mites Sometimes the adult insect is easily seen, such as lice in the hairline or a flea in your bedding. More

Lyme disease rash Once attached and engorged with blood, ticks look more like a wart, mole, or other skin part, and may be missed by someone who does not know your body as well as you do. The appearance of flu- like symptoms, severe headaches, fever, rash, and muscular aches and pains several days to weeks after a confirmed long-term tick attachment or