Abstract: Objective To analyze the species, quantity and distribution of plague host animals and vector fleas in the Inner Mongolia Autonomous Region (Inner Mongolia), China, and understand the situation of human and animal plague, and to provide a scientific basis for accurate prediction of plague epidemics and formulating control countermeasures. Methods According to the National Plague Surveillance Program and Inner Mongolia Plague Surveillance Program, plague surveillance data from 57 surveillance counties in 12 prefectures (leagues) of Inner Mongolia Autonomous Region in 2020 were collected and sorted out. Descriptive epidemiological methods were used to analyze plague epidemics, host density, and flea index. Results In 2020, there were three human plague cases in Inner Mongolia, with two cases of bubonic plague and one case of intestinal plague. Four types of plague foci of Marmaota sibibirica, Spermophilus dauricus, Microtus brandti, and Meriones unguiculatus covering an area of 6 003 hm² were investigated, and 22 710 host animals were captured. The main hosts Meriones unguiculatus and Spermophilus dauricus accounted for 79.55% and 15.32% of the total capture rodents, respectively. The flea infestation rate was 30.38%, and the overall flea index was 0.97. The dominant flea species included Citellophilus tesquorum, Nosopsyllus laeviceps, and Xenopsylla conformis, which accounted for 44.92%, 22.28%, and 20.99% of the total population, respectively. A total of 22 451 host animals and 21 821 fleas were examined, and 99 Yersinia pestis strains were isolated from them. The indirect hemagglutination test detected 6 positive samples from 10 671 serum samples of various host animals. Conclusion The situation of human and animal plague in Inner Mongolia is complicated, which is intense in M. unguiculatus plague foci. It is necessary to strengthen plague monitoring and ensure timely detection and emergency preparedness and response.

Key words: Plague, Host, Vector, Surveillance, Inner Mongolia Autonomous Region

摘要： 目的 分析内蒙古自治区（内蒙古）鼠疫宿主动物及媒介蚤的种类、数量和分布，掌握人间和动物间鼠疫疫情动态，为准确预测鼠疫疫情和制定相应防控对策提供科学依据。方法 按照《全国鼠疫监测工作方案》和《内蒙古自治区鼠疫监测工作方案》的要求，收集整理2020年内蒙古全区12个盟（市）57个监测县（旗、市、区）鼠疫监测资料，运用描述流行病学方法，分析疫情、统计鼠疫宿主动物密度和媒介蚤指数。结果 2020年内蒙古共报告人间鼠疫病例3例，确诊腺鼠疫病例2例，肠鼠疫病例1例；调查蒙古旱獭、达乌尔黄鼠、布氏田鼠、长爪沙鼠4种类型鼠疫疫源地6 003 hm²，捕获各种宿主动物22 710只，主要宿主长爪沙鼠和达乌尔黄鼠分别占79.55%和15.32%；染蚤率为30.38%，总蚤指数为0.97，其中方形黄鼠蚤、秃病蚤和同形客蚤为优势蚤种，分别占44.92%、22.28%和20.99%。检测宿主动物22 451只，蚤21 821匹，分离到鼠疫耶尔森菌99株；间接血凝试验检查各种宿主动物血清10 671份，阳性6份。结论 内蒙古地区人间及动物间鼠疫疫情形势复杂，尤其是长爪沙鼠鼠疫疫源地疫情流行强度高，应加强监测工作，以便及时发现处置疫情，做好应急准备工作。

关键词: 鼠疫, 宿主, 媒介, 监测, 内蒙古自治区