Borrelia burgdorferi in small mammal reservoirs in Kentucky, a traditionally non-endemic state for Lyme disease
The incidence of tick-borne zoonoses such as Lyme disease has steadily increased in the southeastern United States. Southeastern states accounted for 1500 of over 28,000 confirmed cases of Lyme disease reported in the United States during 2015. Borrelia burgdorferi, the etiologic agent of Lyme disease, is maintained in small mammal reservoirs and vectored to new hosts by ixodid ticks. This study examined ecological relationships of the B. burgdorferi/vector/reservoir system in order to understand the dynamics of Lyme disease risk in Kentucky. Small mammals were captured using live traps from November 2014 to October 2015. Ticks were removed and blood and tissue collected from small mammals were screened for B. burgdorferi DNA by PCR with primers specific to the OspA gene. Prevalence of B. burgdorferi (21.8%) in Kentucky small mammals was comparable to the lowest recorded prevalence in regions where Lyme disease is endemic. Moreover, infestation of small mammals by Ixodes scapularis, the primary vector of B. burgdorferi, was rare, while Dermacentor variabilis comprised the majority of ticks collected. These findings provide ecological insight into the relative paucity of Lyme disease in Kentucky.
KeywordsBorrelia burgdorferi Small mammals Vector ecology Ticks Lyme disease
We thank C. Banotai, J. Lee, and K. Bottoms for assisting with sampling in the field. We are grateful to the Green River Preserve for allowing us to conduct sampling on the property. Additionally, A. Meier and O. Meier assisted with coordinating the logistics necessary to conduct the field work. This work was supported by the Western Kentucky University Office of Graduate Studies and Research, WKU Department of Biology, and the Robinson Fund for Research.
Compliance with ethical standards
All procedures involving animals were approved by the Western Kentucky University Institutional Animal Care and Use Committee in permit #14-22 on 4 November 2014.
Conflict of interest
The authors declare that they have no conflict of interest.
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