Infection Prevalence In A Novel Ixodes Scapularis Population In Northern Wisconsin

Ixodes scapularis (i.e. the blacklegged or deer tick) is an important vector of emerging human pathogens. Over the past few decades, the incidence of blacklegged tick-associated zoonotic diseases have increased in accordance with an expansion of the blacklegged tick geographic range. Data concerning the infection prevalence of blacklegged ticks in this region is highly variable and fragmentary. Using a novel population of these ticks, constituting part of the invasion front in Vilas County, Wisconsin, I examined infection prevalence and vector aspects of their ecology. During the summer of 2016, I collected 461 blacklegged ticks and screened them using a standard polymerase chain reaction assay designed to identify three emerging zoonotic pathogens: Borrelia burgdorferi, Anaplasma phagocytophilum, and Babesia microti. The overall infection probability was 30%, 25%, and 14% respectively. The probability of co-infection ranged from 2-6% and the conditional probability of co-infection was not significant, indicating that there are yet to be detectable relationships between co-infecting pathogens. Blacklegged ticks were found in two main vegetation types: Oak and Northern Hardwood. These vegetation types are typical blacklegged tick habitat since they provide an adequate layer of leaf litter which is necessary to prevent desiccation. Overall, my work suggests that blacklegged ticks in this region may be an important source of pathogen pressure. This study aids in a better understanding of the geographic range increase of blacklegged ticks in North America and the entomologic risk posed by these novel populations.