Background and Aim: The Sunda pangolin (Manis javanica) is on the International Union for Conservation of Nature Red List of Threatened Species (critically endangered) due to high levels of illegal trafficking for its products. Thailand is one of the habitats of this species, and it has become the main hub for its illegal trafficking. Rehabilitating these captive pangolins and reintroducing them back to the wild are challenging due to the limited knowledge on their diet, management, and diseases. Hemoparasites, including Babesia spp., can cause important protozoal infections in both domestic and wild animals, resulting in the failure of rehabilitation and conservation programs. However, Babesia spp. has not been reported in pangolins. The aim of the study was to determine the prevalence of Babesia spp. in the Sunda pangolin of Thailand.

Materials and Methods: A total of 128 confiscated Sunda pangolins from across different regions in Thailand were investigated. These pangolins had been admitted to a regional Wildlife Quarantine Center for rehabilitation before release in the forest. Routine physical examinations were conducted on the animals. We collected blood samples from each pangolin for hematological analysis and to detect Babesia spp. using polymerase chain reaction (PCR) targeting the partial 18s rRNA gene.

Results: Babesia-specific PCR detected 53 animals (41.4%) that were positive for Babesia spp. Blood smears were obtained from the positive samples and investigated under a light microscope to observe for trophozoites of Babesia spp. Examination of 40 PCR-positive and -negative samples found no significant differences between the hematological parameters of Babesia-positive and Babesia-negative samples. Eight PCR-positive samples were randomly selected and their DNA was sequenced. Seven and one of sequences match uncharacterized Babesia spp. with 100% and 99.2% similarity, respectively. Phylogenetic analysis demonstrated that our samples form a unique monophyletic clade along with other Babesia spp. detected in the wild. This clade is clearly separated from other Babesia spp. from small carnivores, ruminants, and rats.

Conclusion: Our results provide evidence of infection of Sunda pangolins in Thailand by Babesia spp. These pangolins originated from different regions and had not lived together before blood collection. Thus, we suggest that the uncharacterized Babesia spp. found in this study constitute a new group of pangolin-specific Babesia spp. The prevalence of the uncharacterized Babesia spp. was not correlated to pangolin health. Further studies are required to characterize the genomes and phenotypes, including the morphology and pathogenicity of these protozoa. Such information will be helpful for the conservation and health management of the Sunda pangolin.

Keywords: Babesia spp., Manis javanica, sunda pangolin, Thailand.