Molecular Detection and Phylogenetic Analysis of Anaplasma spp. in Ticks Collected from Grasslands near Livestock Farms in Gyeonggi and Gangwon Provinces, Republic of Korea.

Ticks are hematophagous ectoparasites capable of transmitting a wide array of pathogens. The recent proliferation and geographic expansion of tick populations have intensified concerns regarding the escalating risk of tick-borne pathogen transmission. Among these, Anaplasma phagocytophilum poses a notable threat to both public and veterinary health due to its zoonotic potential. In this study, a total of 4316 ticks were collected from 16 pasture sites near livestock farms in Gyeonggi and Gangwon Provinces, Republic of Korea, between April and October 2024. Molecular epidemiological analysis was subsequently performed. Of the 400 tick pools tested, Ixodes nipponensis accounted for two Anaplasma-positive pools, Haemaphysalis spp. larvae for two pools, and Haemaphysalis longicornis for one pool. This study is the first to examine the infection rate of A. phagocytophilum in ticks collected from pasture sites near livestock farms in Gyeonggi and Gangwon Provinces. Although the observed infection rate was low, the presence of A. phagocytophilum in regions with potential human exposure emphasizes the risk of transmission. Importantly, the detection of A. phagocytophilum in larval-stage ticks suggests the possibility of transovarial transmission, meriting further investigation. These findings underscore the need for conducting surveillance and targeted preventive strategies to reduce the burden of tick-borne diseases in livestock-associated settings.