一起托育机构札如病毒感染暴发疫情调查

Investigation of an outbreak caused by sapovirus in a childcare institution

目的调查一起托育机构札如病毒暴发疫情,探讨疫情暴发的原因及危险因素,为感染性腹泻防控疫情提供参考经验。方法根据2023年5月30日—6月12日感染性腹泻疫情特点,开展现场流行病学调查,包括病例搜索、卫生学调查和病原学检测。采用描述性流行病学方法分析疫情特征以及病例对照研究分析暴发危险因素。结果共发现病例15例,分布于2个班级,太阳班和月亮班的罹患率分别为57.14%、15.79%(χ^(2)=7.278,P<0.05)。发病年龄为2~<4岁,男女病例数分别为9、6人,男女生罹患率均为37.50%。临床症状以呕吐(100.00%)为主,伴有腹泻(26.67%)、腹痛(33.33%)。本次疫情首发病例于6月2日1时发病,2日—7日病例零散出现,8日10时指示病例在班级内呕吐1次,保育老师清理呕吐物并消毒地面,全程未疏散幼儿,9日病例集中出现,达到高峰,9日后无新发病例,疫情持续8天。札如病毒核酸检测阳性率88.89%。卫生学调查排除食品与水源传播可能。病例对照研究显示幼儿的不良卫生习惯、近距离接触呕吐物及暴露于呕吐物下风侧与发病均无统计学关联。结论本次疫情是一起由札如病毒引起的感染性腹泻暴发疫情,带病上课的病例为传染源,呕吐物处置不规范造成气溶胶传播为本次疫情暴发的主要原因。建议加强学校从业人员的传染病防控培训,规范呕吐物的消毒处置。

Objective To investigate an outbreak caused by sapovirus in a childcare institution,explore the causes and risk factors of the outbreak,and provide reference for the effective control of infectious diarrhea.Methods The field epidemiological investigation was conducted including case searches,hygiene investigation and pathogen detection based on epidemic characteristics of infectious diarrhea from May 30th to June 12th,2023.Descriptive epidemiological method was used to analyze the characteristics of the outbreak;case-control studies was used to analyze risk factors of the outbreak.Results A total of 15 cases were found in two classes through case search.The attack rates in Sun class and Moon class were 57.14%and 15.79%,respectively(χ^(2)=7.278,P<0.05).The onset age was between 2-<4 years old.Of the total cases,9 were male,and 6 were female.The attack rates in male and female children were both 37.50%.The clinical symptom was mainly vomiting(100.00%),accompanied by diarrhea(26.67%)and abdominal pain(33.33%).The first case of this outbreak occurred at 1:00 on June 2nd,and the other cases sporadically occurred from 2nd to 7th.At 10:00 on June 8th,the index vomited once in the class.The childcare teacher cleared vomitus and disinfected the floor,but the children were not evacuated throughout the entire process.On the June 9th,the cases occurred concentratively and reached its peak.There were no new cases after June 9th,and the outbreak continued for eight days.The positive rate of sapovirus nucleic acid testing was 88.9%.Hygiene investigations excluded the possibility of food and water transmission.Case control studies showed that there were no statistically significant association of cases incidence with poor hygiene habits,close contact with vomitus,and exposure to the windward side of vomitus in young children.Conclusions This infectious diarrhea outbreak was caused by sapovirus.The cases attending classes with illness was the source of infection,and the improper disposal of vomitus leading to aerosol transmission was the main cause of this outbreak.It is recommended to strengthen the training of infectious disease prevention and control in school employees,and standardize the disinfection and disposal of vomitus.