关键词: 鼠疫, 野鼠, 家鼠, 棕形额蚤

Abstract: Objective To investigate the prevalence of wild rodent plague and commensal rodent infection in Jianchuan county, Yunnan province, China, and to analyze its risk to the population. Methods The host animals, vectors, and indicative animals of the plague among rodents in Jianchuan county in 2017 were investigated. Serological and bacteriological tests related to the plague were carried out on the collected specimens. The χ² test was used to analyze the differences in the distribution of rodents and their parasitic fleas. Results (1) A total of 221 rodents were captured. The densities of indoor and outdoor rodents were 7.00% and 24.66%, respectively, with a significant difference (χ²=73.730, P=0.000). (2) Rattus tanezumi and R. norvegicus were the dominant indoor species; Eothenomys miletus and Apodemus chevrieri were the dominant outdoor species. There was a significant difference in the distribution of species between indoor and outdoor rodents (χ²=160.005, P=0.000). (3) Apodemus chevrieri was infected with 190 fleas; E. miletus was infected with 85 fleas; R. tanezumi was infected with 43 fleas; R. norvegicus was infected with 9 fleas. (4) The major flea species on A. chevrieri was Frontopsylla spadix; the major flea species on E. miletus was Ctenophthalmus quadrarus; the major flea species on both R. tanezumi and R. norvegicus were F. spadix. There was a significant difference in the major flea species between the four species of rodents (χ²=244.272, P=0.000). (5) One strain of Yersinia pestis each was isolated from the naturally dead R. tanezumi and the F. spadix on it, as well as Neopsylla specialis specialis on a living rodent. Conclusion The density of rodents and flea index were high in the wild plague foci of Jianchuan county. Frontopsylla spadix was the dominant species of parasitic fleas on both wild rodents and indoor rodents. The plague epidemic in this area was of high risk based on the assessment.

Key words: Plague, Wild rodent, Commensal rodent, Frontopsylla spadix