Prevalence and zoonotic potential of pathogens in micromammals (rodents and insectivores) in the Republic of Korea

Micromammals (rodents and insectivores), are reservoirs of numerous zoonotic pathogens and play a critical role in infectious disease transmission. The rising prevalence of micromammals-associated pathogens in the Republic of Korea highlights the urgent need for targeted surveillance. Here, we analyzed micromammal blood samples collected from 16 nationwide sites during spring 2022, autumn 2022, and spring 2023 to investigate the following key zoonotic diseases: severe fever with thrombocytopenia syndrome, Lyme disease, Q fever, scrub typhus, anaplasmosis, ehrlichiosis, and rickettsioses. Our analysis revealed that of the 756 micromammal samples analyzed, 0.1 % had Borrelia afzelii, Borrelia valaisiana, and Orientia tsutsugamushi, 12.7 % contained Anaplasma phagocytophilum, and 82 % Neoehrlichia mikurensis. Importantly, we detected Borrelia valaisiana in micromammals in the Republic of Korea for the first time. Phylogenetic analysis identified close genetic links between local and global pathogen strains, highlighting potential cross-border transmission risks. The high prevalence of Neoehrlichia mikurensis emphasizes the zoonotic threat of micromammals. These findings provide crucial insights about enhancing micromammals-associate pathogen surveillance, inform public health strategies, and reinforce the importance of monitoring micromammal populations for zoonotic infection risk mitigation in Korea and beyond.