南昌市水体、水(海)产品中霍乱弧菌污染状况调查和流行病学分析

目的通过对南昌市水体、水(海)产品中霍乱弧菌的系统监测,了解南昌市水体水(海)产品霍乱弧菌的污染状况,为制订霍乱防制策略提供依据。方法在霍乱可能发生流行的季节按月定期在南昌市范围内开展水体、水产品霍乱弧菌的监测,采用聚合酶链反应(PCR)方法对检出的霍乱弧菌的毒力特征进行分析,了解菌株的生物学性状,是否为产毒株,是否有致病力,采用核酸脉冲电泳场技术(PFGE)对水体、水产品中O139型分离株和同一年的霍乱病人及带菌者中的O139型分离株进行同源性分析比较,了解其分子生物学及流行病学特征。结果散发病例中的分离株均为非产毒株,同样有致病力,与外环境的水体、水(海)产品中的分离株无关联,暴发疫情的病例中的分离株均为产毒株,与常规监测的水(海)产品中的分离株有一定相关性,常规监测水体中的分离株均为非产毒株,在表型及基因水平上与病例中的分离株差异较大,不是病例发生的致病菌。结论霍乱疫情输入区散发病例具有偶然发生的特点,常常表现为"来无影、去无踪"的特点,被产毒株污染的水(海)产品是导致暴发疫情发生的主要原因。

Investigation and epidemiological analysis on pollution status of vibrio cholerae in water and aquatic(marine) products in Nanchang

Objective To investigate pollution status of vibrio cholerae in water and aquatic(marine) products through systematical monitoring,so as to provide scientific evidence for formulating cholera preventive measures.Method Regularly monitoring the vibrio cholerae in water and aquatic products by monthly in the possible epidemic season in Nanchang;analyzing the virulence characteristics of detected vibrio cholerae through PCR method,so as to understand the biological character of bacterial strain and see if it’s toxigenic strain and pathogenic;PFGE was used to analyze the homology of type-O139 isolates in water & aquatic products and in cholera patients and carriers in the same year,so as to understand their molecular biological and epidemiological characteristics.Results Isolates from sporadic cases were not toxigenic strains,but they were virulent,which were unrelated to the isolates of water and aquatic(marine) products of external environment.Isolates from epidemic cases were toxigenic strains,which were related to the isolates of routinely-monitored water and aquatic(marine) products.Isolates in routinely-monitored water were not toxigenic strains,and had great diffience with isolates from the cases in aspects of phenotype and genetic level,which were not the pathogenic bacteria.Conclusions Sporadic cases from cholera input area had the characteristic of contingency,and were usually presented as "disappeared as suddenly as it appeared".Aquatic(marine) product contaminated by toxigenic strains was the main reason of the outbreak of epidemic.