Investigating the diversity and small mammal host ecology of Borrelia burgdorferi in rural Ohio

Blacklegged ticks (Ixodes scapularis) readily bite humans, livestock, and companion animals in addition to wildlife hosts allowing for transmission of numerous pathogens of medical and veterinary concern. The most significant of these is Borrelia burgdorferi, the agent of Lyme disease. Cases of human and canine Lyme disease have increased in incidence and distribution along with the range expansion of the blacklegged tick. Emergence of Lyme disease in new areas is the consequence of a confluence of B. burgdorferi, Ixodes ticks, hosts, and the ecological and climatic conditions supporting tick and host populations. In Ohio, the first established blacklegged tick population was detected in 2010 in rural Coshocton County. Little is known about how B. burgdorferi prevalence in the blacklegged tick population has changed since its initial establishment or the pathogen-tick-host relationships of Ohio's small mammal community. Our study aimed to: (1) determine the current prevalence of B. burgdorferi sensu lato (Bbsl), (2) characterize the diversity of B. burgdorferi sensu stricto (Bbss) using outer surface protein C genotyping and multi-locus sequence typing analysis, and (3) investigate pathogen-tick-host relationships. We revisited the index sites in Coshocton County to sample host-seeking ticks and small mammals in 2021 and detected an increase in the overall prevalence of B. burgdorferi. Our study generated new insights on the involvement of non-Peromyscus mammals in the local Lyme disease transmission cycle. Understanding host ecology is valuable for designing effective host-targeted control and surveillance activities as well as making accurate predictions of the continued geographic expansion of Lyme disease.