Assessment of Rabies and Canine Distemper Viruses in Road-Killed Wildlife Mammals From the Semiarid Region of Northeastern Brazil

Road mortality due to collision with vehicles can affect many species, increasing the risk of local population decline or extinction. Infectious diseases that affect the central nervous system of wild animals may also promote an increase in road mortality due to the debilitating effects of blinding, neurologic disturbance, or behavior alteration. Roads in the surroundings of three conservation units in the Caatinga of Rio Grande do Norte, Brazil, were surveyed to identify which mammal species are being impacted by these anthropogenic structures. In addition, collected animals that were recently killed were also examined to determine their health status for diseases that affect the central nervous system (rabies and distemper virus) which cause neurological disorders. Between November 2014 and November 2015, 124 mammals from four potential reservoir species were found road-killed in the surveyed roads. Despite reports of these viruses circulating in Northeast Brazil, in both domestic and wild animal populations, none of the 18 road-killed mammals tested were infected by rabies or canine distemper, although some of the species identified are considered reservoirs for both diseases. This suggests that the animals most likely came from healthy populations or that the prevalence of these diseases is so low that it remained undetected. Furthermore, the high number of road-kills during this 1-year period indicates that mammal species from these conservation units are being negatively impacted, regardless of their health status. Hence, further studies must be conducted to identify other factors contributing to the road-killing of these species and implement the adequate mitigation measures to reduce or eliminate road mortality in the vicinities of these three conservation units.