Caught on the Trail: A Public Health Analysis of Water and Vector-Borne Disease on the Appalachian Trail
Margaret Tomann
Introduction: The Appalachian Trail is one of the most popular hiking destinations in the United States with over 2 million visitors each year. Measuring roughly 2,180 miles, the trail runs through 14 states from Springer Mountain, Georgia to Katahdin, Maine. Hikers on the Appalachian Trail are at risk for water and vector-borne disease due to exposure to open water sources and disease carrying vectors, poor hygiene and inconsistent water treatment methods. Wilderness-acquired disease can lead to shortened trips, and long-term health complications. The objective of this study was to identify what behaviors are most associated with water and vector borne disease and analyze the correlation between hygiene practices and the prevalence of water and vector-borne disease on the Appalachian Trail. The study also examines the impact of disease on the achievement of long distance hiking goals.
Methods: Data was collected through an anonymous online
survey A link was made available through the project website (www.caughtonthetrail.blogspot.com), which
included detailed information on the research purpose, objectives, and
background, as well as researcher contact information and educational
background. Participant recruitment was conducted via online forums and
websites used by Appalachian Trail hikers. The survey was available from
September – December 2013. Analyses were performed using R-Software
(r-project.org) to find correlations between the frequencies of trail behaviors
and the incidence of diarrhea. Categorical variables were compared using
chi-squared tests.
Results: A total of 139 research participants completed the
online survey. Of the 84 hikers who experienced wilderness-acquired diarrhea,
27 reported having hiked in a group. The majority of the behaviors that were
hypothesized to be associated with an increased risk for wilderness-acquired
diarrhea were shown to be insignificant, with a P-value more than 0.05. There
was, however, a significant correlation between those who hiked in a group and
their risk for acquiring diarrhea on the trail. The majority of hikers, 81.8%
(n=112), achieved their hiking goals on a recent Appalachian Trail hike.
Wilderness-acquired diarrhea was not associated with a decreased likelihood of
reaching hiking goal. Eleven hikers reported being diagnosed by a medical practitioner,
five with Giardia lamblia, three with
Calicivirus, and single diagnoses for
each, E.coli, Camplyobacter and H.pylori.
The majority of hikers experienced mosquito bites (88.2%) and tick bites
(52.2%) while hiking the Appalachian Trail. Fourteen participants sought
medical care for vector related illness while on the trail. Of these, eight
were diagnosed with Lyme disease (Lyme
borreliosis), and one with West Nile Virus.
Discussion: It is well established that good hygiene and hand
washing can decrease the risk of disease and poor personal hygiene should be
recognized as a contributing factor to the spread of wilderness acquired
diarrheal illness (CDC, 2013). In addition preventive measures can reduce the
risk and impact of vector borne disease on the Appalachian Trail, including the
ability to recognize signs and symptoms of vector borne illness, avoid prolonged
exposure to ticks, frequent use of insect repellent on person and clothing and
daily examining for ticks (CDC, 2013). Future studies should focus on
alternative explanations for high incidence of diarrhea along the Appalachian
Trail, including diet and food preparation, detailed sources of drinking water,
and practices of open-defecation and the use of outhouses and privies.
Acknowledgements: Immense
appreciation is extended to Amy R. Gordon, of Karolinska University in
Stockholm, Sweden for assistance with statistical analysis and R-Software.
