Ixodes scapularis (i.e. the blacklegged or deer tick) is an important vector of emerging human pathogens. Over the past few decades, an increase in the blacklegged tick’s geographic range has been accompanied by an increase in blacklegged tick-associated zoonotic disease incidence. A novel population of these ticks, constituting part of the blacklegged tick invasion front, was identified in Vilas County, Wisconsin. I examined the infection prevalence and vector ecology by collecting 459 blacklegged ticks during the summer of 2016. The ticks were screened using a standard polymerase chain reaction assay for three emerging zoonotic pathogens: Borrelia burgdorferi, Anaplasma phagocytophilum, and Babesia microti.
Results/Conclusions
The probability of infection was 30%, 25%, and 14% for B. burgdorferi, A. phagocytophilum, and B. microti respectively. The probability of co-infection ranged from 2 to 6%, but the conditional probability of co-infection was not significant. 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. Data concerning the infection prevalence of blacklegged ticks in this region is highly variable and fragmentary. 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.