Lyme disease prevalence and small mammal abundances on Fort Drum Military Installation, New York

In the Northeast, Lyme disease is the most common vector-borne zoonotic infectious disease spread by black-legged ticks (Ixodes scapularis). The potential for impact of active troops and their dependents is a concern among... [ view full abstract ]

In the Northeast, Lyme disease is the most common vector-borne zoonotic infectious disease spread by black-legged ticks (Ixodes scapularis). The potential for impact of active troops and their dependents is a concern among military installations throughout the region. In New York, Fort Drum reported 38 incident cases of Lyme disease from 2004–2013, among the highest number on military installations. Our objective was to estimate abundance and distribution of vector and host populations on Fort Drum to better assess and communicate the potential risk of exposure and contraction of Lyme disease to the human population. We used tick drags to estimate off-host abundance and demographics, and Sherman and Tomahawk traps to estimate small mammal abundance and diversity in six different habitat cover types (deciduous, coniferous, mixed, shrub, developed and developed landscape). Ticks were screened at the Army Public Health Command at Fort Meade, MD with a real-time PCR multiplex for Borrelia burgdorferi. In 2016, approximately 40% of ticks from tick drags were infected with the majority of these occurring in coniferous and mixed habitats. Adult and nymph abundances peaked in spring and summer, respectively. Species composition among 89 captured individuals was: 31% eastern chipmunk (Tamias striatus), 28% deer mice (Peromyscus spp.), 16% red squirrel (Tamiasciurus hudsonicus) and 5% gray squirrel (Sciurus carolinenesis). Although approximately 54% of captured mice had an attached tick, compared to 26% of chipmunks, 100% of attached ticks on chipmunks tested positive, compared to approximately 30% of attached ticks on mice. Captured small mammals occurred predominantly in developed landscape. We will continue to collect field data during 2016 with our overall goal of developing management implications for troop training, recreation, and habitat management on Fort Drum.