title: Medical risks of wilderness hiking.
abstract: OBJECTIVE
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Division of Pulmonary and Critical Care, Department of Medicine and Department of Family Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Boulware
authors.forename: William W
authors.initials: WW
authors.lastname: Forgey
authors.forename: William J
authors.initials: WJ
authors.lastname: Martin
mesh_terms: D000328:Adult; D017677:Age Distribution; D000704:Analysis of Variance; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D005767:Gastrointestinal Diseases / Q000453:epidemiology* / Q000209:etiology; D006306:Health Surveys; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009051:Mountaineering / Q000293:injuries* / Q000706:statistics & numerical data*; D010809:Physical Fitness / Q000502:physiology; D011336:Probability; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D017678:Sex Distribution; D011795:Surveys and Questionnaires; D014947:Wounds and Injuries / Q000453:epidemiology* / Q000209:etiology