Abstract: Objective To investigate the changes in population number and structure of parasitic fleas of Meriones unguiculatus in the natural plague focus Kangbao pasture in Hebei province, China from 1981 to 2020, and to provide a basis for early warning of epizootics in this focus. Methods Excel 2010 software was used to perform year-by-year and month-by-month analyses on the data of rat body fleas, burrow fleas, and nest fleas of M. unguiculatus. The concentration degree method was used to analyze the seasonal distribution of parasitic fleas. Randomized block analysis of variance was used to analyze the flea index of different types of parasitic fleas of M. unguiculatus. Results From 1981 to 2020, a total of 4 046 fleas were collected, belonging to 17 species of 11 genera under 3 families. A total of 122 Xenopsylla conformis conformis fleas were collected from M. unguiculatus bodies from 2018 to 2020, accounting for 7.24% (122/1 684). There was no significant regularity in the infestation rate changes of body fleas, burrow fleas, and nest fleas, but the infestation rates of body fleas and nest fleas were higher than the average level in 1995, 2002-2003, 2005, and 2017-2018 when epizootics occurred. The concentration degree method found that both body fleas (M=0.3) and nest fleas (M=0.3) of M. unguiculatus had certain seasonality, and they tended to change inversely-one rose as another fell; M. unguiculatus burrow fleas had strong seasonality (M=0.7), with flea density higher in summer and autumn and lower in winter and spring. The randomized block analysis of variance showed a significant difference in the flea index between different types of parasitic fleas of M. unguiculatus (F=3.515, P=0.023), and multiple comparison showed significant differences in the flea index between any two types of body fleas, burrow fleas, and nest fleas (all P<0.05). Conclusion Plague epizootics were associated with the parasitic flea infestation rate of M. unguiculatus in the natural plague focus Kangbao pasture of Hebei province from 1981 to 2020, which provides a theoretical basis for targeted flea control measures to prevent plague.

Key words: Plague, Natural focus, Meriones unguiculatus, Parasitic flea, Hebei province

摘要： 目的 了解河北省鼠疫自然疫源地康保牧场1981－2020年长爪沙鼠寄生蚤种群数量和结构变化规律，为该疫源地动物疫情的预测预警提供依据。方法 应用Excel 2010软件对长爪沙鼠鼠体蚤、洞干蚤及窝巢蚤调查数据进行总结和逐年逐月统计，运用集中度法对寄生蚤季节分布特征进行分析，采用配伍组方差分析对不同类型长爪沙鼠寄生蚤蚤指数进行分析。结果 1981－2020年共计获蚤4 046匹，隶属于3科11属17种，其中2018－2020年长爪沙鼠鼠体捡获同形客蚤122匹，占比7.24%（122/1 684）；鼠体蚤、洞干蚤和窝巢蚤的染蚤率变化没有一定的规律性，但1995、2002－2003、2005、2017－2018年有动物间鼠疫疫情发生，鼠体蚤和窝巢蚤染蚤率均高于平均染蚤率；应用集中度法研究发现长爪沙鼠体蚤（M=0.3）和巢蚤（M=0.3）均有一定的季节性，且二者呈现“此起彼伏”的变化趋势；长爪沙鼠洞干蚤有很强的季节性（M=0.7），蚤密度夏秋较高，冬春较低；经配伍组方差分析，不同类型的长爪沙鼠寄生蚤蚤指数差异有统计学意义（F=3.515，P=0.023），鼠体蚤、洞干蚤和窝巢蚤的蚤指数分别进行两两比较，差异均有统计学意义（均P<0.05）。结论 1981－2020年河北省鼠疫自然疫源地康保牧场动物间鼠疫流行与长爪沙鼠寄生蚤染蚤率存在一定的相关性，为有针对性地开展该疫源地灭蚤防控鼠疫提供了理论依据。

关键词: 鼠疫, 自然疫源地, 长爪沙鼠, 寄生蚤, 河北省