2018—2022年南宁市中小学生流感疫情特征分析

Characteristics of influenza epidemics among primary and middle school students in Nanning City,2018-2022

目的 分析探讨2018—2022年南宁市中小学生流感疫情特征,为下一步开展流感防控工作提供科学依据。方法 收集2018—2022年南宁市报告的所有普通中小学学生流感病例信息、流感样病例监测信息、流感暴发性疫情信息,建立流感信息数据库;对数据进行统计分析,采用描述性流行病学研究方法分析流行病学特征。结果 2018—2022年南宁市累计报告普通中小学生流感病例共22 864例,占总报告数的38.62%。学生流感发病趋势呈波浪形,具有明显的季节性,每年的冬春季节是病例报告的高峰期,流感样病例监测发现流感存在冬季和夏季双峰的活动规律;年龄中位数为9(8,12)岁,每年报告的病例年龄差异无统计学意义(P=0.053);以小学生为主(76.02%),随着学校级别增高,病例报告数呈现逐年递减的趋势(P=0.000);男性发病人数多于女性(P=0.022),男女性别比为1.39∶1;流感暴发性疫情主要集中在小学(P=0.564);哨点医院累计报告流感样病例129 662例,占门急诊病例就诊总数的6.22%;每年甲、乙型流感病毒均有检出,但每年的优势毒株种类不同;学校流感暴发性疫情主要集中在小学。结论 2018—2022年南宁市中小学生流感疫情有明显的季节性,小学生是重点人群,小学是流感暴发的主要场所,应重点加强小学生的流感防控工作。

Objective To analyze and explore the characteristics of influenza epidemics amongst pupils and middle school students in Nanning City from 2018 to 2022,and to provide a scientific basis for conducting influenza prevention and control work in the next step.Methods We collected the reported information about influenza cases,surveillance of influenza-like illness(influenza-like,ILI)cases and influenza outbreaks of all primary and secondary school students reported in Nanning from 2018 to 2022,and established adatabase regarding the influenza information.The data were analyzed statistically,and descriptive epidemiological research methods were used to analyze the epidemiological characteristics.Results A total of 22,864 cases of influenza were reported in the primary and secondary school students in Nanning City from 2018 to 2022,accounting for 38.62%of the total reported cases.The incidence of influenza among the students presented a wavy trend,and showed obvious seasonality.The peak of reported cases occurred in winter and spring every year,and the activity pattern of double peaks in winter and summer was found in the surveillance of ILI cases.The median age was 9 years(range 8-12),and there was no statistically significant difference in the age of reported cases from year to year(P=0.053).The majority of the reported cases were primary school students(76.02%).With the increase of school level,the number of reported cases showed a decreasing trend year by year(P=0.000).The number of male cases was more than that of female ones(P=0.022),and the sex ratio between males and females was 1.39:1.The outbreaks of influenza were mainly concentrated in primary schools(P=0.564).A total of 129,662 ILI cases were cumulatively reported in sentinel hospitals,accounting for 6.22%of the total outpatient and emergency cases.Influenza A and B viruses were detected every year,but the dominant strains were different from year to year.The outbreaks of influenza in schools were mainly concentrated in primary schools.Conclusion The influenza epidemics among the primary and middle school students in Nanning City show obvious seasonality.Pupils are the key population,and primary schools are main places of theinfluenza outbreaks.Hence,influenza prevention and control in pupils should be intensified.