title: An Assessment of Diarrhea Among Long-Distance Backpackers in the Sierra Nevada.
abstract: BACKGROUND
  Diarrhea is a common problem among long-distance backpackers, ranging in overall incidence from 11-56% as reported by previous studies on the Appalachian Trail and Long Trail. Differences in age, sex, and regularity of standard backcountry hygiene recommendations and practices have been shown to significantly affect the incidence of diarrhea. No study to date has investigated these trends among long-distance backpackers on the John Muir Trail (JMT) in the Sierra Nevada mountain range of California.
  
  
  METHODS
  Retrospective analysis of online survey data gathered from long-distance backpackers who attempted a JMT trek in 2014. Data were assessed for the significance of variables that might contribute to the incidence and severity of on-trail diarrhea.
  
  
  RESULTS
  Of 737 valid responders, 16.4% reported experiencing diarrhea (82% with minimal/mild severity; 18% with significant severity). Regular hand sanitizer use was significantly correlated with more severe diarrhea (P < .05), but had no effect on incidence. Regular hand sanitizer users followed all other recommended hygiene practices as frequently as or better than those not using hand sanitizer regularly. Of all backpackers, 88% filtered or treated their drinking water regularly, with 18% of those reporting diarrhea of any severity.
  
  
  CONCLUSIONS
  JMT backpackers have a comparatively lower incidence of diarrhea than backpackers on other major long-distance backpacking routes in the United States. Most JMT backpackers follow standard backcountry hygiene recommendations, including regular filtration or treatment of drinking water. No statistical significance was found between the incidence of diarrhea and compliance with standard hygiene recommendations. Regular hand sanitizer use was significantly correlated with more severe diarrhea but was not associated with incidence. There was no significant difference in compliance with standard backcountry hygiene practices between regular and infrequent hand sanitizer users.
authors.affiliation: Department of Emergency Medicine, UCSF Fresno, Fresno, CA (Drs Meyer and Spano). Electronic address: meyerdj@ah.org.
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Meyer
authors.affiliation: California State University-Fresno, Fresno, CA (Ms Constantino).
authors.forename: Amber
authors.initials: A
authors.lastname: Costantino
authors.affiliation: Department of Emergency Medicine, UCSF Fresno, Fresno, CA (Drs Meyer and Spano).
authors.forename: Susanne
authors.initials: S
authors.lastname: Spano
mesh_terms: D000328:Adult; D002140:California; D003967:Diarrhea / Q000453:epidemiology* / Q000209:etiology; D060766:Drinking Water; D005260:Female; D006306:Health Surveys; D006801:Humans; D006920:Hygiene; D008297:Male; D008875:Middle Aged; D009051:Mountaineering / Q000706:statistics & numerical data; D012189:Retrospective Studies
chemical_list: D060766:Drinking Water
keywords: John Muir Trail; Sierra Nevada; backpacking; diarrhea; hand sanitizer