Date: 2014-02-12
From: Springer Mtn

To: Katahdin
Miles today: 0.0

Preventing Lyme Disease on the Appalachian TrailWant to hike but don¢t want to get Lyme disease? If you hike in the mid-Atlantic, New England, upper Midwest states or lower elevations of California, one of the biggest hazards of hiking is exposure to Lyme disease, Figure 1. I hope inform you about ticks and how to avoid ticks in general and Lyme disease in particular, making your hike a safer experience.Tick Primer: Various diseases are transmitted by ticks, especially Lyme disease. About 300,000 cases of Lyme disease are estimated annually by the Centers for Disease Control and Prevention, with high incidence in the mid-Atlantic and New England states. (Note: the vast majority of these cases are likely attributable to tick exposure from populated lower elevations). The disease is caused by the bacterium Borrelia burgdoferi and transmitted via the deer tick Ixodes scapularis which occurs commonly and bites humans in wet northern deciduous forests and I. pacificus in California. Juvenile (nymph-Figure 2) life stages cause the large proportion of Lyme disease cases and are so small (the size of a poppy seed) that even when attached, they are often not noticed except by careful skin checks. Ticks do not jump or fly, but quest for hosts on low vegetation or leaf litter.Lyme disease not only causes a flu-like illness often with expanding rash, but can also cause a poorly understood, long-term, debilitating, chronic Lyme disease syndrome in up to 10-20% of treated cases. 60% of untreated cases can result in significant joint swelling and arthritis, and a smaller percent experience neurological problems (http://www.cdc.gov/lyme/signs_symptoms/index.html). Lyme disease is a significant health risk to uninformed and ill-prepared hikers. Babesiosis and human anaplasmosis are two other less common diseases associated with deer ticks. Co-infections of two or more pathogens often occur, complicating treatment.While Lyme disease cases vastly outnumber other tick-borne disease cases, other ticks and tick-borne pathogens are also known to occur. In the eastern U.S., the lone star tick Ambylomma americanum and the American dog tick Dermacentor variabilis are vectors of ehrlichiosis and spotted fever rickettsia diseases. These ticks are more prevalent in the southern states and tend to be found more in grassy fields. The lone star tick can also cause a red meat allergy. The principle tick vector in the west is the Rocky Mountain wood tick, Dermacentor andersoni, vector of Rocky Mountain spotted fever and tularemia.Season and elevation determine exposure to ticks. In a 2013 tick survey on the Appalachian Trail, I started my northbound hike at Springer Mountain, Georgia in mid-April and despite doing tick surveys, I did not encounter any ticks in Georgia, North Carolina, Tennessee, nor southern Virginia, where I arrived in mid-May. Elevation and cold weather suppress ticks. Ticks (adult and nymphs) were more common from central Virginia to Massachusetts through mid-July. Ticks are more abundant at the lower elevation (less than 2500¢) deciduous forests and occasional fields of Virginia. Researchers have found few deer tick nymphs above 1650¢ in the Mid-Atlantic States. Many trails in these states are mostly less than 2000¢ in elevation and provide the greatest deer tick and Lyme disease exposure. Elevation combined with the more northern latitudes and sub-alpine coniferous forest and alpine areas, may explain why ticks are less common in the mountains above 2000¢ in Vermont, New Hampshire and Maine. Sub-alpine coniferous forest and alpine vegetation is poor tick habitat. It is possible to encounter ticks of one species or another in lower elevations of most states from April through September (and even year-round at the very low elevations). The highest exposure months for the Appalachian Mountains are mid-May through July when nymphs are most abundant. Preventative Measures:¢¢        Know when and where deer tick exposure is most likely.¢¢        The most important preventative is to wear factory-treated permethrin clothing and to treat one¢s shoes, pack and outer tent floor with spray-on permethrin. Permethrin binds tightly to clothing, is safe for humans, and I can attest is highly repellant of ticks, spiders and insects, (http://www.epa.gov/pesticides/factsheets/factory-treated-clothing.html). I recommend the treated ventilating bug-net pants, long-sleeved shirt and hat. ¢¢        Apply 20-30% DEET on exposed skin, although use it sparingly and according to directions on adults and children because DEET is toxic. Higher concentrations are unnecessary. If you have covered your body as above, only hands and face are exposed and alternatively, wear a head net.¢¢        Hike the center of the trail and use caution hiking off-trail, such as in collecting firewood. Tick exposure can be reduced by regular trail, field, power-line, and shelter area trimming. ¢¢        Avoid sitting on the ground or logs and avoid setting your pack or gear on the ground if possible. Treat a closed cell sit pad with permethrin for rest breaks on the trail.¢¢        Avoid pitching your tent in leaf piles or grass. Tents may be safer than tarps. Bare ground is safer than areas covered with leaf litter or grass and is in accordance with Leave No Trace principles. Shelters and picnic tables are fairly safe places, but examine them first.¢¢        Hiking and camping with dogs will attract ticks to dogs. Close contact as in petting or sleeping may cause the ticks to attack you. ¢¢        It is essential to make time for a daily (or more frequent) tick check. Look for adult or juvenile (nymph) ticks (see photo). Enlist a hiking buddy to check your back. Perform a partial check of body and clothing during breaks or after collecting firewood and do a more complete check at the end of the day.¢¢        Hikers should be able to identify deer ticks, and recognize the symptoms of Lyme disease (http://www.cdc.gov/lyme/ or http://www.lymediseaseassociation.org). ¢¢        Immediately remove any attached tick with forceps with a slow, steady pull and wash the bite area carefully with soap and water and/or sanitizer. ¢¢        Seek medical treatment immediately if any flu-like symptoms of Lyme disease appear and know that an expanding rash may or may not be present. Don¢t let ticks spoil your hike or keep you indoors. There would be fewer cases of Lyme disease if hikers were more aware of ticks and tick-borne disease and wore protective clothing during their hike. Make your hike a safe and enjoyable one by following these preventative measures.