Abstract: Objective To summarize and analyze the species and number of vector fleas and the current situation of Yersinia pestis in them in the plague foci of Meriones unguiculatus in Ulanqab Plateau, Inner Mongolia, China, 2011-2020, and to analyze the epidemic characteristics of plague in natural foci, in order to provide a theoretical basis for the prevention and control of plague. Methods Year-round flea monitoring was carried out in 20 banners (counties) of leagues (cities) in plague foci of M. unguiculatus in Ulanqab Plateau, Inner Mongolia. Sampling was stratified by habitats, and various rodent ectoparasitic fleas and nest fleas were captured and were identified using opaque specimens, counted, and registered for the isolation of Y. pestis. Excel 2003 software was used to analyze the species and number of fleas and Y. pestis infection in different years by descriptive epidemiology. Results From 2011 to 2020, a total of 41 930 fleas were collected from the plague foci of M.unguiculatus in Ulanqab Plateau, Inner Mongolia, including 3 superfamilies, 5 families, 14 genera, and 28 species (subspecies). The number of species of fleas captured each year varied from 17 to 23, with an average of 18.8 species per year. The number of fleas captured in each year were 2 012-7 979, with an average of 4 193 fleas captured each year. Yersinia pestis was isolated from 163 fleas of 3 species (subspecies) in 5 years, including 9 fleas of 1 species in 2011, 53 fleas of 2 species in 2017-2018, and 101 fleas of 3 species in 2019-2020. The flea infection rate of M. unguiculatus was 22.72% and the flea index was 0.67. Conclusion In recent years, the ecological environment of Ulanqab Plateau in Inner Mongolia changed due to natural and social factors, the species, number, and Y. pestis infection of plague-vector fleas showed some new characteristics. Nosopsyllus laeviceps. Xenopsylla conformis, and Neopsylla bidentatiformis were the dominant species, while the Neo. pleskei orientalis decreased greatly. In the future, it is necessary to further strengthen the monitoring and research of vector fleas in this area to prevent the spread of plague to humans.

Key words: Ulanqab Plateau, Meriones unguiculatus, Plague foci, Flea

摘要： 目的 整理2011－2020年内蒙古自治区（内蒙古）乌兰察布高原地区长爪沙鼠鼠疫疫源地媒介蚤的种类、数量和分离鼠疫耶尔森菌（鼠疫菌）等监测数据，分析该疫源地动物鼠疫流行特点，为进一步做好鼠疫防控工作提供理论依据。方法 在内蒙古乌兰察布高原地区长爪沙鼠鼠疫疫源地的5个盟（市）20个旗（县）常年开展蚤类监测，按不同生境分层进行抽样，将捕获的各种鼠类体外寄生蚤和鼠巢蚤，进行不透明标本的分类鉴定和计数登记后，对鼠疫菌进行分离。所获调查数据应用Excel 2003软件分别对蚤种类、数量及其感染鼠疫情况按不同年代采用描述流行病学方法进行统计分析。结果 2011－2020年在内蒙古乌兰察布高原长爪沙鼠鼠疫疫源地共获蚤类3总科5科14属28种（亚种）41 930匹。统计数据显示：各年度获蚤种类在17～23种，年平均获蚤种类为18.8种；各年度获蚤数量在2 012～7 979匹，平均每年捕获4 193匹；有5个年度从3种（亚种）163匹蚤中分离出鼠疫菌，其中2011年在1种9匹蚤、2017－2018年在2种53匹蚤中检出鼠疫菌，2019－2020年在3种101匹蚤中检出鼠疫菌。长爪沙鼠的染蚤率为22.72%，蚤指数为0.67。结论 内蒙古乌兰察布高原地区近年来由于生态环境受到自然和社会多方面因素的影响，致使当地鼠疫媒介蚤的种类、数量及感染鼠疫的情况出现了一些新的特点，其中秃病蚤、同型客蚤和二齿新蚤为优势种，而近代新蚤东方亚种大幅度下降，今后应进一步加强该地区媒介蚤类的监测和研究，防止鼠疫传播到人间。

关键词: 乌兰察布高原, 长爪沙鼠, 鼠疫疫源地, 蚤类