Detection of tick-borne pathogens from rescued wild animals

Climate change is associated with the accelerated maturation of ticks, shortened life cycles of ticks, and increased tick density. Land development, such as deforestation, often results in the loss of wildlife habitats, leading to frequent human-wildlife contact. Consequently, these climate and habitat factors pose the increasing risk of emerging tick-borne diseases to both humans and wildlife. This study aimed to detect tick-related pathogens by analyzing blood and spleen samples of rescued animals in wildlife rescue centers in the Republic of Korea (ROK). In this study, a total of 376 samples from 355 animals, including 160 wild birds, 131 Korean water deer (Hydropotes inermis), 49 raccoon dogs (Nyctereutes procyonoides), 11 Siberian roe deer (Capreolus pygargus), 2 leopard cats (Prionailurus bengalensis), and 2 Asian badgers (Meles leucurus) were collected. All samples have been stored at -20℃ freezer before DNA and viral RNA extraction. RT-PCR and nested PCR were conducted to detect tick-borne pathogens and for phylogenetic analysis. As a result, 6 samples tested positive for severe fever with thrombocytopenia syndrome virus (SFTSV), 146 for Anaplasma phgocytophilum, 55 for A. bovis, 45 for Borrelia spp., 12 for Rickettsia spp., and 12 for Bartonella spp. The phylogenetic analysis indicated that SFTSV belonged to Subgenotypes B-1 and B-3. Among bacteria, Bartonella (B.) schoenbuchensis and Borrelia theileri were identified. These findings suggest that wild animals are potential reservoirs of diverse tick-borne pathogens in natural environments and that effective surveillance systems are required to prevent transmission among ticks, wildlife, and humans using the One Health approach.