Higher Prevalence of than in Small Mammal Species in Central Pennsylvania, United States.

can lead to severe babesiosis in immunosuppressed populations, but due to high numbers of asymptomatic cases, clinical reporting is unable to define its geographic distribution. Although Lyme disease caused by is endemic throughout Pennsylvania (PA), human babesiosis is under recognized, despite sharing the same vector and primary reservoir host. ticks are known to carry throughout PA, but information about pathogen prevalence in small mammal reservoirs remains limited. Characterizing prevalence in these small mammals can elucidate mechanisms of pathogen spread and define geographic areas where humans are at risk of infection. We tested 692 small mammals across eight contiguous counties in central PA for molecular evidence of and In total, six different small mammal species were collected. The overall prevalence of was 32% with similar rates observed across all counties. Surprisingly, this was higher than the prevalence of at 21%. In fact, high rates of were found in all six species, and both pathogens were identified in 11% of mammals tested. The prevalence of was highest in (southern red-backed vole) at 39% despite (white-footed mouse) being considered the primary reservoir host for In conclusion, has a high prevalence across multiple small mammal species throughout central PA. This prevalence is greater than despite a much higher incidence of Lyme disease compared to babesiosis in PA. Although it remains unknown how the prevalence of in small mammal hosts corresponds to human infection rates, the high pathogen prevalence of suggests that it is an emerging pathogen in this area. Currently, babesiosis is not a reportable disease in PA, and additional studies are warranted to evaluate its clinical significance in this geographic region.