一起学校甲型副伤寒暴发疫情的病原学调查

目的对引起一起传染病暴发的病原菌进行实验室检测和分析,为疫情的处理提供科学依据。方法采用流行病学调查与实验室检测相结合的方法。采集发热患者血标本547份,市政供水水样188份,学校自备水6份,食品33份,食品、供水从业人员及患者密切接触者粪便1 310份,按GB/T 4789.4-2008和W S/T 13-1996方法进行检测。结果 547份血标本检出甲型副伤寒沙门菌89株,阳性率16.27%(89/547);1 310份肛拭子检出甲型副伤寒沙门菌6株,阳性率0.46%(6/1 310);188份市政供水水样和6份学校自备水样均未检出甲型副伤寒沙门菌,市政供水余氯含量符合国家饮用水卫生标准要求,学校自备水均未检出余氯,但大肠菌群、菌落总数超过国家饮用水卫生标准。33份食品未检出甲型副伤寒沙门菌。结论引起此次疫情暴发流行的病原菌为甲型副伤寒沙门菌。自备水源受到污染引发病例和与患者接触传播是引起此次甲型副伤寒暴发的主要原因。

Pathogen investigation on an outbreak of paratyphoid A in school

[Objective]To carry out the laboratory detection and analysis on pathogen that caused an infectious disease outbreak,provide scientific basis for epidemic treatment.[Methods]Using combined method of epidemiological investigation and laboratory detection,547 blood samples of patients with fever,188 water samples of municipal water supply,6 water samples of school self-prepared water,33 food samples,and 1 310 fecal samples of employees in food industry and water supply,and close contacts of patients were collected,and were tested according to GB /T 4789.4-2008 and WS /T 13-1996.[Results]Among 547 blood samples,89 strains of Salmonella paratyphi A were detected with the positive rate of 16.27%(89/547).Among 1 310 anal swabs,6 strains of Salmonella paratyphi A were detected with the positive rate of 0.46%(6/1 310).Among 188 water samples of municipal water supply and 6 water samples of school self-prepared water,Salmonella paratyphi A was not detected.The residual chlorine content of municipal water supply met the national health standard of drinking water.In school self-prepared water,the residual chlorine was not detected,but the coliform bacteria and total bacterial count exceeded the national health standard of drinking water.Salmonella paratyphi A was not detected in 33 food samples.[Conclusion]The pathogen of this infectious disease outbreak is Salmonella paratyphi A.The main causes of this outbreak of paratyphoid A are pollution of self-prepared water source and close contacts of patients.