Appalachian Trail hikers' ability to recognize Lyme disease by visual stimulus photographs.

Background: Lyme disease is the most common vector-borne infectious disease in North America. With nearly 2,500 Appalachian Trail (AT) hikers entering the endemic area for as long as 6 months, exposure to the disease is likely. The characteristic exanthem of erythema migrans (EM) should be a trigger for seeking medical treatment, and its recognition in this relatively isolated environment is important.

Objective: The purpose of this study was to determine the ability of AT hikers to identify EM, the exanthem of Lyme disease.

Methods: Hikers were administered a photographic stimulus in this Internal Review Board-approved pilot study. Historical hiking data, basic demographics, and self-reported treatment and diagnosis were collected.

Results: In all, 379 responses were collected by 4 researchers at 3 geographically separate locations at or proximate to the AT from June 2011 to May 2012. Fifty-four percent of respondents (206 of 379) were able to recognize the photographs of EM/Lyme disease; 46% could not. Of those who did recognize EM, 23 (6%) had seen it either on themselves or on another hiker while on the AT. A total of 37 hikers stated that they had been diagnosed with Lyme disease while hiking, and of these, 89% were treated with antibiotics. Thirteen of these 37 hikers (35%) diagnosed with Lyme disease had visualized an embedded tick. Nine percent of all respondents reported they had been diagnosed with Lyme disease by a healthcare practitioner, whether from EM, symptomatology, or by titer.

Conclusions: This study suggests that hikers are poorly able to recognize the characteristic exanthem of Lyme disease but have a high exposure risk.