1起诺如病毒引发校园急性胃肠炎暴发疫情的流行病学调查分析

Epidemiological investigation on an outbreak of norovirus acute gastroenteritis in a school

[摘要]目的掌握连云港市某学校一起诺如病毒急性胃肠炎暴发疫情的原因和流行特征。方法对连云港市某学校诺如病毒急性胃肠炎病例进行个案调查,对调查数据完成描述性及分析性流行病学分析;采集病例肛拭子、呕吐物以及厨房冷菜、荤菜刀板涂抹样、22日三餐食物标本、直饮水滤芯涂抹样,用PCR法进行肠道病毒核酸检测。结果 2018 年 5 月 22 日 10:00—5 月 24 日 4:00 连云港市某学校 3 720 名学生中共计发生急性胃肠炎 80 例,罹患率2.15%,其中男生罹患率2.14%(52例),女生罹患率2.17%(28例),差异无统计学意义(P>0.05)。小学部罹患率3.89%(35例)高于初中部的1.19%(24例)和高中部的2.61%(21例)。5份肛拭子、1份呕吐物以及厨房冷菜刀板涂抹样核酸检测诺如病毒 GⅡ阳性。5 月 22 日晚餐中食用京酱肉丝(含生黄瓜丝)是发病的危险因素(OR=6.00,95%CI:1.30~27.70),并且随着该菜食用比例的增加,急性胃肠炎的发病呈明显升高趋势(χ~2=5.561,P=0.020)。结论此次疫情是由诺如病毒GⅡ型引起的胃肠炎暴发,学校应重视对食品加工过程中的卫生清洗、消毒工作,确保水果及凉菜的安全卫生,同时积极开展健康教育工作,加强学生预防传染病的意识。

Objective To grasp the causes and epidemiological characteristics of an outbreak of norovirus acute gas-troenteritis in a school in Lianyungang City.MethodsThe cases of norovirus acute gastroenteritis were investigated in aschool in Lianyungang City.The survey data were analyzed by the descriptive and analytical epidemiological methods.Theanal swabs,vomit samples,kitchen cold dishes,simmering smears,food samples on May 22,2018,and drinking water filtersmears were collected and detected by PCR for enterovirus nucleic acid.ResultsThere were 80 cases of acute gastroenteri-tis among 3720 students in a school in Lianyungang City from 10:00 a.m.,May 22,2018 to 4:00 p.m.,May 24,2018,and theincidence was 2.15%.In the incidence rate,there was no significant difference between the boys(52 cases,2.14%)and girls(28 cases,2.17%)(P>0.05).The incidence rate in the primary school(35 cases,3.89%)was higher than that in the middleschool(24 cases,1.19%)and in the high school(21 cases,2.61%).The collection of 5 anal swabs,1 vomit sample and kitchencold knife plate smear was detected as Norovirus GII positive.The risk factor for this outbreak was Beijing sauce pork(includ-ing raw cucumber silk)at dinner on May 22(OR=6.00,95%CI:1.30-27.70),and the incidence of acute gastroenteritis showedan upward trend significantly as the proportion of the dish increased(χ~2=5.561,P=0.020).ConclusionThe outbreak of gas-troenteritis is caused by norovirus GII.The work of sanitary cleaning and disinfection in food processing should be paid atten-tion to,in order to ensure the safety and hygiene of fruits and cold dishes.In addition,the school authority should actively car-ry out health education and strengthen students’awareness of preventing infectious diseases.