Medical risks of wilderness hiking

PURPOSE: We sought to determine the extent to which injuries and illnesses limit long-distance or endurance outdoor recreational activities. METHODS: In a prospective surveillance study, 334 persons who hiked the Appalachian Trail for at least 7 days (mean [+/- SD] length of hike, 140 60 days) in 1997 were interviewed. At the end of their hike, subjects completed a questionnaire on injuries, illnesses, water purification methods, and hygiene practices. RESULTS: Of the 280 backpackers who responded (a combined 38,940 days of wilderness exposure), 69% (n = 192) achieved their goal. The most important reasons for ending a hike prematurely were injury, time limitation, and psychosocial reasons. The most common medical complaints were feet blisters (64%; n = 180), diarrhea (56%, n = 156), skin irritation (51%, n = 143), and acute joint pain (36%, n = 102). The incidence of vector-borne disease was 4% (n = 11); physician-diagnosed Lyme disease was the most common, and 24% of hikers (n = 68) reported tick bites. The risk of diarrhea was greater among those who frequently drank untreated water from streams or ponds'(odds ratio [OR] = 7.7; 95% confidence interval [CI]: 2.7 to 23; P < 0.0001), whereas practicing "good hygiene" (defined as routine cleaning of cooking utensils and cleaning hands after bowel movements) was associated with a decreased risk (OR = 0.46; 95% CI: 0.22 to 0.97; P = 0.04). CONCLUSION: Diarrhea is the most common illness limiting long-distance hikers. Hikers should purify water routinely, avoiding using untreated surface water. The risk of gastrointestinal illness can also be reduced by maintaining personal hygiene practices and cleaning cookware. (C) 2003 by Excerpta Medica Inc.