Detection of vector-borne infections in nondomestic mammals at a single zoological institution

In zoological facilities, the high density of species, presence of various arthropod vectors, and potential interaction with free-ranging wildlife hosts and vectors may increase the risk of vector-borne infections. Vector-borne organisms have the potential to cause severe disease and death; however, healthy nondomestic mammals can also harbor these organisms without clinical signs. The objective of this study was to identify the presence of vector-borne infections from a single zoological facility and document the potential transmission of endemic vector-borne infections to nondomestic species. Samples from 149 healthy nondomestic mammals representing 41 species across six different field habitats at the San Diego Zoo Safari Park (SDZSP) were analyzed for Anaplasma, Apicomplexa, Babesia, Bartonella, Ehrlichia, and hemotropic Mycoplasma DNA by PCR amplification. All animals were nonclinical at the time of collection. Vector-borne infection prevalence was 19.5% (29/149) across 13 different bovid, cervid, and rhinocerotid species surveyed. The majority of positive animals were born at SDZSP (76%; 22/ 29) and were adults (> 1 year old) (93%; 27/29). Coinfections were found in two animals. Prevalence of individual vector-borne infections included Theileria sp. dama gazelle (n = 12), Mycoplasma ovis (n=11), Anaplasma ovis (n=3), Mycoplasma ovis–like (n=2), Candidatus Mycoplasma erythrocervae (n=1), Bartonella schoenbuchensis (n=1), Theileria bicornis (n=1), and Babesia sp. CA (n=1). This study identified potentially zoonotic vector-borne organisms (Babesia sp. and Anaplasma sp.) in nondomestic hoofstock in a zoological facility. Cohabitation with native free-ranging wildlife is suspected to have resulted in cross-transmission of Babesia and Anaplasma spp. to nonnative zoological species. These findings demonstrate the utility of vector-borne infection surveillance in zoological institutions to inform species management, understand occupational risks for wildlife care staff, and help guide coexistence practices involving native free-ranging wildlife.