Molecular detection of Leishmania and other vector-borne agents in free-ranging and captive herpetofauna from Costa Rica

Vector-borne pathogens in amphibians and reptiles represent an emerging concern in wildlife, with implications for ecosystem dynamics and potential zoonotic risks. In this study, we screened 108 animals from Costa Rica, including 46 captive snakes, 24 free-ranging reptiles, and 38 free-ranging amphibians, for the presence of Trypanosomatidae, Anaplasmataceae, <i>Borrelia</i>, <i>Rickettsia</i>, and <i>Hepatozoon</i> spp. Blood smear analysis revealed protozoa gametocytes in 3.7 % of the animals sampled, and 11.1 % of amphibians and reptiles were molecular positive for at least one pathogen. Specifically, 7.4 % of the samples tested positive for <i>Leishmania</i> spp., 1.85 % for <i>Trypanosoma</i> spp., 0.9 % for <i>Anaplasma</i> spp., and 1.85 % for <i>Hepatozoon</i> spp. Notably, this study reports the first molecular detection of <i>Leishmania</i> in an amphibian species (<i>Rhinella horribilis</i>) and confirms the presence of mammalian pathogenic <i>Leishmania infantum</i> in captive snakes in Central America. The presence of potential zoonotic agents in both captive and free-ranging herpetofauna underscores the importance of screening wildlife species, including understudied host groups such as amphibians, to better understand their role in disease ecology.