Rising seroprevalence of Borrelia spp. in free roaming felines in the eastern Tennessee valley

Understanding the range and potential spread of tick-borne pathogens is vital for the protection of susceptible animals and humans. Free-roaming feline populations may serve as unique sentinel hosts for tick-borne illnesses because of their high association with human-populated areas and high interface with ticks. Our study analyzed indirect immunofluorescence assay (IFA) of feline serum collected from 2019 to 2020 and 2013-2014). Samples were screened for Ehrlichia spp., Rickettsia spp., and Borrelia spp. Due to the high seroprevalence of Borrelia spp., additional samples were tested over multiple time periods to characterize potential chance. Results demonstrated Borrelia spp. in 41.3 % of the 2019-2020 samples and 9.7 % of the 2013-2014 samples. Generalized linear models were constructed to determine the factors correlated with positive Borrelia spp. cases; however, none of the models were statistically significant for predicting Borrelia spp. infection in free-roaming cats. This novel detection method demonstrated high prevalence of Borrelia spp. likely B. burgdorferi in free-roaming cats in the Eastern Tennessee Valley region of the U.S., an area that has seen significant changes in tick population and human disease in the past 20 years. While the specific role of free-roaming cats as sentinel hosts in disease cycling is still unknown, free-roaming cats may serve as reliable predictors for human infections over time. This study underscores the importance of implementing parasite prevention measures for ectoparasites and vectors in trap-neuter-release facilities and highlights the impact that free-roaming cats may have on vector-borne diseases.