1起学校新型冠状病毒感染聚集性疫情流行病学分析  

Epidemiological analysis of a cluster of COVID-19 cases in a school

作　　者：张丽芳[1] 韩继周 何志群[3] 赵世文[1] 张勇[1] 付朝智 杨云娟[1] 常利涛[1] 尹洁[1] ZHANG Lifang;HAN Jizhou;HE Zhiqun;ZHAO Shiwen;ZHANG Yong;FU Chaozhi;YANG Yunjuan;CHANG Litao;YIN Jie(Yunnan Provincial Center for Disease Control and Prevention,Kunming 650022,Yunnan,China;Dehong State Center for Disease Control and Prevention,Dehong 678499,Yunnan,China;Longchuan County Center for Disease Control and Prevention,Longchuan 678700,Yunnan,China)

机构地区：[1]云南省疾病预防控制中心,云南昆明650022 [2]德宏州疾病预防控制中心,云南商德宏678499 [3]陇川县疾病预防控制中心,云南陇川678700

出　　处：《中国校医》2023年第9期663-667,共5页Chinese Journal of School Doctor

摘　　要：目的对云南省陇川县1起感染新型冠状病毒(COVID-19)Delta变异株的学校聚集性疫情进行流行病学调查分析,探讨该传染病在聚集性场所的传播模式和指标,为学校COVID-19有效防控提供科学依据。方法现场调查并通过中国疾病预防控制信息系统收集2021年12月陇川县某中学1起COVID-19聚集性疫情资料。使用频数(n)描述病例三间分布,比较采用Fisher精确检验;根据暴露史估算潜伏期和代间距,数据正态性检验使用Z评分和Shapiro-Wilk检验。结果该聚集性疫情总罹患率2.32%(37/1594),班级罹患率2.08%~46.43%,宿舍罹患率16.67%~100%。二代病例占67.57%(25/37),首发病例宿舍续发率100%(4/4)、班级续发率45.45%(25/55);主动就诊占5.41%(2/37),密接筛查占94.59%(35/37);宿舍发病率16.67%~100%。病例症状依次为咽痛12例(57.14%)、咳嗽9例(42.85%)、鼻塞6例(28.57%)、头疼5例(23.81%)、发热4例(19.05%)、咳痰4例(19.05%)、流涕/喷嚏3例(14.29%)、乏力1例(4.76%)、头晕1例(4.76%)、腹泻1例(4.76%)、胃痛1例(4.76%)。该起COVID-19疫情病例潜伏期为2~8 d,平均为(5.94±1.58)d,众数6.5 d,中位数6.5 d,四分位数间距1.38 d;代际间距分布范围为1~5 d,平均为(3.25±1.03)d,众数3 d,中位数3 d,四分位数间距1.66 d。基因测序显示与国内前期疫情无关联,基因谱共4个代际,突变位点42~45个,传代时间7 d。结论Delta变异新冠病毒传代时间短,传播力强。聚集是其流行的主要表现形式,寄宿制学校尤为明显。潜伏期病例和无症状感染者可作为传染源导致传播和流行。Objective To investigate and analyze an epidemic of Delta variant of novel coronavirus disease(COVID-19)in a school cluster in Longchuan County,Yunnan Province;to explore the transmission patterns and indicators of cluster epidemic,so as to provide scientific evidence for the effective prevention and control of COVID-19 in schools.Methods Data from one COVID-19 school cluster in Longchuan County in December 2021 were collected through field investigation and the Information System for Disease Control and Prevention of China CDC.Frequency(n)distribution was used to describe the distribution of cases,and Fisher's exact test was used to analyze the epidemiological characteristics of cases.The incubation period and intergenerational spacing were estimated based on exposure history.Z-scores and Shapiro-Wilk tests were used to test data normality.Results The total incidence rate of the cluster was 2.32%(37/1594),the incidence rate of the class was 2.08%-46.43%,and the incidence rate of the dormitory was 16.67%-100%.Second-generation cases accounted for 67.57%(25/37),the second-case dormitory recurrence rate was 100%(4/4),and the class recurrence rate was45.45%(25/55).Active visits accounted for 5.41%(2/37)and close screening accounted for 94.59%(35/37).The incidence rate of the dormitory was 16.67%-100%.The symptoms of the cases were as follows:sore throat in 12 cases(57.14%),cough in 9 cases(42.85%),nasal congestion in 6 cases(28.57%),headache in 5 cases(23.81%),fever in 4 cases(19.05%),sputum cough in 4 cases(19.05%),runny nose/sneeze in 3 cases(14.29%),fatigue in 1 case(4.76%),dizziness in 1 case(4.76%),diarrhea in 1 case(4.76%),and stomach pain in 1case(4.76%).The incubation period of the COVID-19 case was 2-8 d,the average was(5.94±1.58)d,the mode was 6.5 d,the median was 6.5 d,and the interquartile range was 1.38 d.The intergenerational interval distribution range was 1-5d,the mean was(3.25±1.03)d,the mode was 3 d,the median was 3 d,and the interquartile range was 1.66 d.Gene sequencing showed that there was no

关 键 词：学校 新型冠状病毒感染 疾病暴发流行 流行病学 

分 类 号：R183[医药卫生—流行病学]