Prevalence of Rickettsiales in raccoon dogs (Nyctereutes procyonoides koreensis) in South Korea: a three-year survey.

Abstract

Importance: The raccoon dog (Nyctereutes procyonoides), native to East Asia, is a key reservoir of zoonotic diseases, crucial for understanding tick-borne pathogen (TBP) transmission in ecosystems.

Objective: This study aimed to assess the prevalence of Rickettsiales pathogens including Anaplasma, Ehrlichia, and Rickettsia species in raccoon dogs across South Korea over a three-year period (2021-2023).

Methods: A total of 275 blood samples were collected from raccoon dogs across nine wildlife centers in South Korea. Molecular detection of pathogens was conducted using polymerase chain reaction to identify Anaplasma, Ehrlichia, and Rickettsia species.

Results: The study revealed an overall infection rate of 10.5% for Anaplasma phagocytophilum and 0.4% for Rickettsia conorii ssp. raoultii. Notably, this represents the first molecular detection of R. conorii ssp. raoultii in raccoon dogs. No samples tested positive for Ehrlichia spp. The central region of South Korea geographically had the highest prevalence of A. phagocytophilum, while all cases of R. conorii ssp. raoultii were detected in the northern region.

Conclusions and relevance: These findings highlight the raccoon dog as a reservoir for TBPs, especially A. phagocytophilum and R. conorii ssp. raoultii, and emphasize the need for further research on its role in public health and zoonotic disease ecology in South Korea.