An Assessment of Diarrhea among Long-Distance Backpackers in the Sierra Nevada

Abstract

The John Muir Trail (JMT) is a 210-plus mile, long-distance backpacking trail in the Sierra Nevada mountain range of California. Previous studies from the Appalachian Trail and Long Trail have found significant correlation between backpacker demographics and on-trail hiking behaviors and diarrhea incidence, ranging from 10.7% to 63%. Incidence of diarrhea also has been shown to depend on age, sex, and regularity of standard backcountry hygiene practices. However, no studies to date have examined these variables among backpackers on the JMT. To determine the significance of particular JMT backpacker demographics and hygiene compliance regularity with diarrhea incidence and severity. Survey data from long-distance backpackers who attempted a JMT trek in 2014 were assessed via statistical software for the significance of variables that might contribute to the incidence and severity of on-trail diarrhea. These variables included age, sex, prehike body weight, prehike physical activity (hours/week), prehike self-assessed physical condition, previous hiking or backpacking experience (days in previous 10 years), solo or group backpacking itinerary, on-trail average pack-weight, on-trail hygiene compliance regularity (water filtration, hand hygiene, dish washing), and posthike difficulty assessment. Backpackers also reported their on-trail incidence and severity of diarrhea. Of 737 valid responders, 16.4% reported experiencing diarrhea (82% with minimal or mild severity; 18% with significant severity). No statistical significance was found between diarrhea incidence as related to hiker demographics or compliance with standard hygiene recommendations. Regular hand sanitizer use was significantly correlated with having more severe diarrhea, but had no effect on incidence. Most JMT backpackers follow standard backcountry hygiene recommendations. JMT backpackers have comparatively lower risk of experiencing diarrhea than other major long-distance backpacking routes in the United States. Diarrhea incidence is unaffected by backpacker demographics or hygiene compliance regularity on the JMT.