Exposure Among National Park Service Employees During an Epizootic: Devils Tower National Monument, Wyoming, 2015.

Tularemia is a zoonotic infection caused by the highly infectious bacterium . Persons having outdoor professions are more likely than others to be exposed to through increased contact with arthropods, infected animals, and contaminated aerosols. After a tularemia epizootic during July and August 2015 at Devils Tower National Monument and an associated tularemia infection in a park employee, we assessed seroprevalence of antibodies, risk factors for seropositivity, and use of protective measures among park employees. Seroprevalence among participating employees was 13% (3/23). Seropositive employees reported multiple risk factors for exposure through both job-related and recreational activities. Activities reported by more seropositive than seronegative employees included using a power blower (67% vs. 5%,  = 0.03), collecting animal carcasses (100% vs. 30%,  = 0.047), and hunting prairie dogs recreationally (67% vs. 5%,  = 0.03). Seropositive employees reported exposure to more ticks (median 30, range 25-35) than seronegative employees (median 6, range 0-25,  = 0.001). Most employees used protective measures (, insect repellent) inconsistently but increased use after receiving educational materials. Educating and enabling at-risk employees to use protective measures consistently, both at work and during recreational activities, can reduce exposure during epizootics.