Shenzhen Bao'an Center for Disease Control and Prevention, Shenzhen, China.
Hezhou Center for Disease Control and Prevention, Hezhou, China.
BMC Infect Dis. 2021 Jan 12;21(1):54. doi: 10.1186/s12879-021-05762-z.
An outbreak of acute gastroenteritis occurred in a kindergarten located Shenzhen City on March 4, 2018. We were invited to investigate to the risk factors associated with this outbreak.
We conducted retrospective cohort-studies on three different groups of subjects in order to figure out the difference of incidence of acute gastroenteritis among subjects of different activities on March 2: group one consisted of people who attended the Lantern festival activities; group two consisted of children and employees who ate breakfast and bread provided by the kindergarten; and groups three consisted of children and employees who did not eat breakfast or bread provided by the kindergarten. Fecal, anal swabs, dishware swabs and hand swabs specimens were collected in the study. Bacteria known to cause acute gastroenteritis were cultured. Viruses associated with acute gastroenteritis were tested using real-time PCR. Capsid gene fragment of 557 bp of norovirus was amplified and sequenced. The phylogenetic tree was constructed with MEGA 7.0 using neighbor-joining method based on capsid gene fragment of norovirus.
A total of 143 suspected cases were identified in this outbreak. Diarrhea happened more often in adults than in children while emesis and bellyache were more frequently found in children than in adults. Higher AGE incidence was observed in group 2, children and employees who had breakfast in the kindergarten on March 2, as well as in group 3, and among employees who eating bread involved in breakfast provided on March 2. Five anal swab specimens were positive for norovirus. All noroviruses belongs to group II.3 and have an identity more than 99%.
A chef, as an asymptomatic carrier with norovirus, was the infectious resource in this outbreak. He contaminated breakfast food provided on March 2. Although morning check is implemented in kindergartens of China, employees are often excluded in morning check. Our finding highlights the importance of morning check covering employees and periodical training for cooks.
2018 年 3 月 4 日，深圳市某幼儿园发生一起急性胃肠炎暴发疫情。我们应邀对该起暴发疫情的危险因素进行调查。
采用回顾性队列研究方法，对 2018 年 3 月 2 日不同活动的 3 组人群罹患急性胃肠炎的差异进行分析，组 1 为参加元宵节活动的人群，组 2 为在幼儿园进早餐和食用幼儿园提供的面包的儿童和教职员工，组 3 为未在幼儿园进早餐和食用幼儿园提供的面包的儿童和教职员工。采集粪便、肛拭子、餐具和手拭子标本，进行细菌培养、病毒检测，采用实时荧光 PCR 方法检测诺如病毒，扩增诺如病毒衣壳基因片段并测序，应用 MEGA7.0 软件构建基于诺如病毒衣壳基因片段的系统进化树。
本次疫情共报告疑似病例 143 例，成人以腹泻为主，儿童以呕吐、腹痛为主。组 2（3 月 2 日在幼儿园进早餐和食用幼儿园提供的面包的儿童和教职员工）和组 3（未在幼儿园进早餐和食用幼儿园提供的面包的儿童和教职员工）罹患急性胃肠炎的比例明显高于组 1（参加元宵节活动的人群），差异有统计学意义（χ²值分别为 11.66、9.55，均 P<0.01）。5 份肛拭子标本诺如病毒核酸检测阳性，均属于诺如病毒Ⅱ.3 型，核苷酸序列同源性为 99%以上。
此次疫情由 1 名携带诺如病毒但无症状的厨师作为传染源，污染了 3 月 2 日提供的早餐食物引起。我国幼儿园虽已实施晨午检制度，但员工常被排除在晨午检之外。本起疫情提示晨午检应覆盖教职员工，同时需加强对厨师的培训。
