广东省2015-2022年流感暴发疫情特征分析

Epidemiologic characteristics and influencing factors of influenza outbreaks in Guangdong Province,2015-2022

目的分析广东省2015年1月至2022年8月报告的流感样病例暴发疫情,掌握广东省流感暴发疫情的流行病学特征。方法针对2015-2022年广东省发生的暴发疫情,收集疫情现场处置信息,对疫情特征进行描述流行病学分析,采用logistic回归模型确定影响暴发疫情强度及持续时间的因素。结果广东省共报告流感暴发疫情1901起,总罹患率为2.05%;疫情报告时间主要集中在11月至次年1月(50.24%,955/1901),4-6月(29.88%,568/1901);珠江三角洲地区的报告暴发疫情占59.23%(1126/1901);中、小学校为疫情发生的主要场所(88.01%,1673/1901)。暴发疫情以发病数10~29例为主(66.18%,1258/1901),持续时间以7 d内为主(50.93%,906/1779)。幼儿园(aOR=0.38,95%CI:0.15~0.93)、珠江三角洲地区(aOR=0.60,95%CI:0.44~0.83)、首例发病时间距离报告时间(与≤3 d相比,>7 d的aOR=3.01,95%CI:1.84~4.90)、甲型H1N1(aOR=2.02,95%CI:1.15~3.55)、B(Yamagata)系(aOR=2.94,95%CI:1.50~5.76)引起与暴发疫情发病人数有关;停课(aOR=0.65,95%CI:0.47~0.89)、珠江三角洲地区(aOR=0.65,95%CI:0.50~0.83)、报告时间距离首例发病时间(与≤3 d相比,>7 d的aOR=13.33,95%CI:8.80~20.19;4~7 d的aOR=2.56,95%CI:1.81~3.61)与暴发疫情持续时间有关。结论广东省流感暴发疫情存在冬春季和夏季2个高峰。中、小学校是高发场所,尽早报告疫情是控制学校流感暴发疫情的关键措施,同时应该采取综合性措施防止疫情蔓延。

Objective To grasp the epidemiological characteristics of influenza outbreaks in Guangdong Province by analyzing the outbreaks of influenza-like cases reported in Guangdong Province from January 2015 to the end of August 2022.Methods In response to the outbreak of epidemics in Guangdong Province from 2015 to 2022,information on on-site epidemic control was collected,and epidemiological analysis was conducted to describe the characteristics of the epidemics.The factors that influence the intensity and duration of the outbreak were determined through a logistic regression model.Results A total of 1901 influenza outbreaks were reported in Guangdong Province,with an overall incidence of 2.05%.Most outbreak reports occurred from November to January of the following year(50.24%,955/1901)and from April to June(29.88%,568/1901).A total of 59.23%(1126/1901)of the outbreaks were reported in the Pearl River Delta region,and primary and secondary schools were the main places where outbreaks occurred(88.01%,1673/1901).Outbreaks with 10-29 cases were the most common(66.18%,1258/1901),and most outbreaks lasted less than seven days(50.93%,906/1779).The size of the outbreak was related to the nursery school(aOR=0.38,95%CI:0.15-0.93),the Pearl River Delta region(aOR=0.60,95%CI:0.44-0.83),the time interval between the onset of the first case and the time of report(>7 days compared with≤3 days:aOR=3.01,95%CI:1.84-4.90),the influenza A(H1N1)(aOR=2.02,95%CI:1.15-3.55)and the influenza B(Yamagata)(aOR=2.94,95%CI:1.50-5.76).The duration of outbreaks was related to school closures(aOR=0.65,95%CI:0.47-0.89),the Pearl River Delta region(aOR=0.65,95%CI:0.50-0.83)and the time interval between the onset of the first case and the time of report(>7 days compared with≤3 days:aOR=13.33,95%CI:8.80-20.19;4-7 days compared with≤3 days:aOR=2.56,95%CI:1.81-3.61).Conclusions An influenza outbreak in Guangdong Province exhibits two peaks,one in the winter and spring seasons and the other in the summer.Primary and secondary schools are high-risk areas,and early reporting of outbreaks is critical for controlling influenza outbreaks in schools.Furthermore,comprehensive measures should be taken to prevent the spread of the epidemic.