Serologic evidence of exposure to livestock-associated pathogens in free-ranging mountain tapir (Tapirus pinchaque) in Ecuador
Mountain tapir (Tapirus pinchaque) are endangered Andean ungulates for which infectious disease exposure in free-ranging populations remains poorly characterized. Between 2016 and 2018, serum samples were collected during field anesthesia events conducted for conservation management purposes within Cayambe-Coca National Park, Ecuador, and tested for selected bacterial and viral pathogens of livestock and zoonotic relevance, including Brucella spp., Leptospira spp., bovine viral diarrhea virus (BVDV), bovine herpesvirus 1 (BoHV-1), vesicular stomatitis virus (VSV), as well as Eastern and Western equine encephalitis viruses (EEEV, WEEV). Nine serum submissions representing eight individuals were evaluated using microscopic agglutination testing (MAT) for Leptospira spp., fluorescence polarization assay (FPA) with confirmatory complement fixation (CF) and repeat FPA testing at the U.S. National Veterinary Services Laboratories (NVSL) for Brucella spp., plaque reduction neutralization testing (PRNT) for EEEV and WEEV, and serum neutralization (SN) assays for BVDV, BoHV-1, and VSV. Most samples were seronegative for all tested pathogens (6/8 individuals; 75%), with all samples negative for antibodies to EEEV, WEEV, BVDV, BoHV-1, and VSV. However, one individual tested positive for Brucella antibodies, and one demonstrated antibodies to multiple Leptospira serovars. These findings provide baseline serologic data and indicate that exposure to pathogens associated with livestock, wildlife, and shared environments can occur within Andean landscapes that include both protected areas and adjacent human-use zones. Detection of Brucella antibodies, a pathogen of particular zoonotic and reproductive significance that may circulate in livestock and wildlife, highlights the importance of integrated pathogen surveillance across wildlife, livestock, and environmental interfaces. Serologic results indicate prior exposure rather than active infection or clinical disease. Continued integrated surveillance may improve understanding of pathogen circulation, exposure sources, and One Health risks in Andean ecosystems.