甘宁黄土高原鼠疫自然疫源地50年防控概述

Overview of prevention and control in Loess Plateau plague natural foci in Gansu and Ningxia for 50 years

目的通过对甘宁阿拉善黄鼠鼠疫疫源地50年鼠疫调查及监测材料汇总分析,为该疫源地动物鼠疫监测及预警提供指导。方法收集、整理鼠疫资料,建立甘宁黄土高原黄鼠疫源地1962—2012年鼠疫数据库;黄鼠密度调查采用1日弓形夹法,其他小型啮齿动物调查采用5 m夹线法;鼠疫病原学的分离采取剖检鼠类脏器,取肝脾直接压印培养法;鼠体蚤的收集采用梳检法;蚤的细菌学检验采取集组研磨培养法;鼠疫血清学采取间接血凝(IHA)法。结果该疫源地共捕获啮齿动物18种,黄鼠为优势种群;收集蚤类59种(亚种),方形黄鼠蚤蒙古亚种为优势种群;50年来发生3次动物间鼠疫流行,分离鼠疫菌163株(其中人尸体4株、自然染疫动物135株、寄生蚤24株),检出阳性血清488份;动物鼠疫流行多发生在5—6月,流行年份黄鼠密度(3.26±1.11)只/hm2,动物间鼠疫频发区在海原县境内月亮山与南华山草甸草原和山地草原地带。结论海原县境内月亮山与南华山为该疫源地核心区,黄鼠鼠疫终止流行阈值指标为黄鼠密度年均<0.2只/hm2,黄鼠密度年均1.11只/hm2为动物鼠疫流行时的阈值指标,2只/hm2为动物鼠疫流行的预警指标。

Objective To summarize and analyze data of investigation and surveillance in Spermophilus alaschanicus plague foci in Gansu and Ningxia for 50 years, to provide guidance for the surveillance and precaution of animal plague in the loci. Methods The plague data were collected to establish plague databases of the Loess Plateau loci from 1962--2012. One-day bow-clip method was taken to investigate Spermophilus alaschanicus density, while investigation on other small ro- dents was carried out by placing a trap at intervals 5 meters. Autopsy was performed on organs of rodents for etiological isola- tion of Yersinia pestis. Liver and kidney were cultured by direct impression. Fleas on the body were collected by combing to make bacteriological analysis by group grinding culture. And IHA was carried out. Results Totally 18 species of rodents were captured with Spermophilus alaschanicus of the dominant populations in the foci. And 59 kinds of fleas （subspecies） were collected, with Citellophilus tesquorus mongolicus of the dominant species. For the 50 years, there were 3 times of plague epidemic in animals and 163 strains of Yersiniapestis （including 4 strains from human corpses, 135 stains from natural- ly infected animals and 24 strains from parasitic fleas）, 488 samples ofsera were detected positive. The animal plague epidemic oc- curred mostly in May and June, with the density of Spermophilus dauricus of （3.26± 1.11） ind./hm： in the prevalent year. The plague in animals occurred frequently in meadow steppe and mountain steppe zone in Moon Mountains and Nanhuashan with- in Haiyuan County. Conclusions Moon Mountains and Nanhuashan within Haiyuan County are the core area of the loci. Threshold indicator is less than 0.2 ind./hm2 annually for epizootic plague terminated, 1.11 ind./hm2 of Permophilus dauricus annually for prevalence of the animal plague, and 2 ind./hm： for the precaution of animal plague epidemic.