关键词: 恙虫病, 自然疫源地, 鼠类, 恙螨, 恙虫病东方体

Abstract: Objective To investigate the species compositions of rodents and the chigger mites on their body surface and the infection rate of Orientia tsutsugamushi in rodents in Yongcheng, Henan province, China, and to provide a scientific basis for the prevention and control of scrub typhus in Yongcheng. Methods Rat traps were used to capture rodents and to collect ectoparasites from the body surface of rodents in different survey sites and different habitats in Yongcheng in October 2017. Nested PCR was used to detect nucleic acid of O. tsutsugamushi. The rodent density, chigger infestation rate, chigger index, and pathogen infection rate were calculated. Results A total of 110 rodents were captured with a capture rate of 12.21%. Apodemus agrarius accounted for 90.00%. A total of 1 249 chigger mites were collected from rodents. The chigger infestation rate and chigger index were relatively high in the forest along the riverbank, wetland, and mountain forest. Leptotrombidium scutellare (96.86%) was the dominant chigger mite species, which was mainly parasitic on the body surface of A. agrarius. The O. tsutsugamushi positive rate of rodent was 10.48%. Apodemus agrarius, Rattus norvegicus, and Mus musculus were detected O. tsutsugamushi positive with nPCR. Orientia tsutsugamushi in Yongcheng belonged to Kawasaki molecular type. Conclusion This study confirms that there are some epidemic foci of scrub typhus with host rodents in Yongcheng, which have the same hosts and vectors as the surrounding epidemic foci of scrub typhus.

Key words: Scrub typhus, Nature focus, Rodent, Chigger mite, Orientia tsutsugamushi