一起幼儿园诺如病毒暴发疫情及GⅡ型感染者排毒时间的调查分析

Investigation and analysis of a kindergarten norovirus outbreak and detoxificationtime of patients with type GⅡ infection

目的分析一起幼儿园暴发疫情特征,针对暴发疫情中感染诺如病毒GⅡ型的教职工开展排毒期调查,为采取针对性控制措施提供参考。方法采用描述性流行病学方法分析疫情特征,采集部分儿童病例和全体教职工肛拭子、粪便或呕吐物标本进行诺如病毒检测;针对感染诺如病毒GⅡ型的教职工开展排毒时间调查,每间隔1~7 d采集教职工感染者肛拭子或粪便标本进行检测,直至阴性。结果该园共350名儿童,146人发病,罹患率为41.71%,所有班级均有病例;主要症状为呕吐。教职工共计49人,其中确诊病例24人,主要症状为腹泻;隐性感染者13人;教职工感染率75.51%。教职工GⅡ型感染者排毒期最短为发病后7 d,最长20 d,中位数为12 d;其中确诊病例排毒期中位数13 d明显高于隐性感染者的9 d。幼儿病例的呕吐物样本11份、肛拭子样本2份,检测8份GⅡ型;49名教职工肛拭子或粪便标本检出36人感染GⅡ型,1人感染GⅠ型。结论该起疫情是由诺如病毒感染引起的感染性腹泻暴发疫情,感染GⅡ型诺如病毒的确诊病例排毒时间长于隐性感染者。

Objective To analyze the characteristics of an outbreak in a kindergarten,and to investigate the detoxification period of faculty members infected with norovirus GⅡin the outbreak,so as to provide reference for taking targeted control measures.Methods Descriptive epidemiological methods were used to analyze the epidemic characteristics.Anal swabs,feces or vomit samples of some children and all teaching staff were collected for norovirus detection.In addition,the detoxification time of faculty members infected with norovirus GⅡ was investigated,and their anal swabs or fecal samples were collected every 1~7 days for detection until they were negative.Results There were 350 children in the kindergarten,146 of whom were ill,and the incidence rate was 41.71%.Their main symptom was vomiting.There are 49 faculty members in total,including 24 confirmed cases whose main symptom was diarrhea and 13 recessive infections.Therefore,the infection rate of faculty members was 75.51%.The shortest detoxification period of GⅡ infection in faculty members was 7 days after onset,the longest was 20 days,and the median was 12 days.Among them,the median of 13 days in the detox period of confirmed cases was significantly higher than the 9 days of recessive infections.There were 11 vomit samples,2 anal swab samples and 8 GⅡ samples from children’s cases.Anal swabs or fecal samples of 49 faculty members were tested,36 people were infected with type GⅡ and one was infected with type GⅠ.Conclusion This is an outbreak of infectious diarrhea caused by norovirus infection.And the detoxification time of confirmed cases infected with GⅡ norovirus is longer than that of recessive infections.