广东省某农村学校因生活用井水被GⅡ-4型诺如病毒污染引起胃肠炎暴发调查  

Investigation of a gastroenteritis outbreak caused by well water polluted by norovirus GⅡ4 in rural schools in Guangdong

作　　者：孙立梅[1] 陈少雄[2] 梁骏华[1] 吴小玲[3] 李晖[1] 何昌云[1] 周晓红[4] 

机构地区：[1]广东省疾病预防控制中心,广东广州510300 [2]广东省潮州市疾病预防控制中心 [3]广东省茂名高州市疾病预防控制中心 [4]广州市红十字会医院

出　　处：《现代预防医学》2012年第7期1618-1621,共4页Modern Preventive Medicine

摘　　要：目的通过对1起农村学校诺如病毒感染引起的胃肠炎暴发调查,分析感染传播途径,为农村及集体单位饮用水管理提供依据。方法采用主动搜索、问卷调查等方法对2009年9月广东省某农村中学急性胃肠炎暴发进行调查,采用描述性流行病学方法进行分析;采集病例肛拭子、井水及自来水用RT-PCR方法进行诺如病毒核酸检测和测序分析。结果广东省某农村学校胃肠炎暴发的指示病例发病时间为2009年9月4日,疫情历时8d,共搜索到病例108例,罹患率1.8%(108/5854);病例以学生为主(占85.2%,92/108),另有15名教师及1名校门卫发病;临床症状主要表现为腹泻(99.1%,107/108)、腹痛(82.4%,89/108)和呕吐(72.2%,78/108),82名病例病程中位数2d(P25～P75为2～3d),无住院病例;病例在班级及宿舍分布未见明显空间聚集性;学生是否在学生食堂就餐罹患率分别为1.7%(90/5418)、3.0%(2/66),教师是否在教师食堂就餐罹患率分别为7.7%(11/143)、3.5%(5/142),学生及教师有无在学校就餐罹患率差异无统计学意义(χ2=0.1、1.6,P﹥0.05);生活使用井水人群罹患率(2.0%,47/2324)是使用自来水人群罹患率(1.0%,14/1367)的2倍(RR=2.0,95%CI1.1～3.6)。采集9份现症病例肛拭子标本进行诺如病毒核酸RT-PCR检测,6份标本呈阳性;采集消毒前井水及井水末梢水各1份和自来水1份,其中2份井水诺如病毒核酸检测均呈阳性,自来水诺如病毒核酸检测为阴性。选取3份肛拭子阳性标本和1份井水进行序列测定,4份标本核酸相似性为100%,经与GenBank进行BLAST比较属于诺如病毒GⅡ-4群。结论广东省某农村学校发生1起GⅡ-4型诺如病毒感染的胃肠炎暴发,主要传播途径是因生活使用的井水受到诺如病毒污染,加强农村及集体单位饮用水管理是当前各级政府及相关部门重中之重工作。OBJECTIVE To investigate the transmission mode of norovirus infection of a gastroenteritis outbreak occurred in a rural schools in Guangdong,which provided basis for management of rural and collective unit water supply.METHODS Used the descriptive epidemiology,we took initiative search,questionnaire survey and so on in the gastroenteritis outbreak.We collected anal swabs from patients,well water samples and tap water samples.Norovirus nucleic acids were tested and sequenced.RESULTS The onset date of the index case was September 4th in 2009,and the outbreak lasted eight days.108 cases were founded and the attack rate was 1.8%（108/5 854）.The main cases were among students,accounting for 85.2%（92/108）,with 15 teachers and 1 doorkeeper.The main clinical symptoms were as follows：diarrhea（99.1%,107/108）,abdominal pain（82.4%,89/108）and vomit（72.2%,78/108）.The course of the disease median of 82 cases was 2 days（P25-P75 was 2-3 days）,without hospitalized cases.The distribution of cases in classes and dormitories did not appear any distinct spatial aggregation.The attack rates of students having meals in the school canteen or not were 1.7%（90/5 418）,3.0%（2/66）,respectively.The attack rates of teachers having meals in the school canteen or not were 7.7%（11/143）,3.5%（5/142）.There was no statistical difference of attack rates comparing students and teachers eating at school or not（χ2 = 0.1,1.6,P﹥0.05）.People who drank well water had an attack rate of 2.0%（47/2 324）,which was two times of those who drank tap water,with the attack rate 1.0%（14/1 367）（RR=2.0,95%CI 1.1-3.6）.6 out of 9 anal swabs were positive for norovirus nucleic acid RT-PCR tests.We collected a sample of disinfected well water,well in pipeline water and tap water,respectively.The two samples of well water were positive norovirus nucleic acid tests,while the tap water test was negative.3 anal swabs positive specimens and one sample of well water were undertaken sequence tests,nucleotide sequence analys

关 键 词：暴发 诺如病毒 现场流行病学 学校 水污染 GⅡ-4型 

分 类 号：R181.81[医药卫生—流行病学]