Investigation and analysis of an outbreak of influenza A(H1N1)in a primary school in Yuzhong District,Chongqing in 2023
Objective To investigate and analyze the epidemiological characteristics and and influencing factors of an influenza A(H1N1)outbreak in a primary school in Yuzhong District,Chongqing,and explore the key points of influenza prevention and control in schools.Methods According to the Guidelines for Out-break Management of influenza-like Cases(2018 edition),on-site investigation,disposal and data collection were carried out,and descriptive epidemiological methods were used to analyze the epidemic characteristics and find the causes of the outbreak.Results The onset of the first case was February 21,2023,and the outbreak lasted 37 days in total,a total of 224 influenza-like cases have been reported,and the incidence rate was 11.14％.The epidemic affected 28 classes of four grades in the school,and the incidence rate of students in dif-ferent teaching buildings,floors,grades and classes had statistical significance(P＜0.05),the cases were mainly distributed in the second floor of Houde Building(Grade 1),among which the highest incidence was found in Class 7 of Grade 1(53.33％),and the distribution of floors and classes was consistent;the infection rate of students who did not receive seasonal influenza vaccine was significantly higher than that of students who had received seasonal influenza vaccine,and the difference was statistically significant(X2=14.231,P＜0.05),the vaccine protection rate was 50.04％,and the efficacy index was 2.0.Conclusion The outbreak was a school influenza outbreak caused by influenza A(H1N1)virus,suggested that improve hygiene conditions,comprehensive control measures and vaccination were the focus of school influenza prevention and control,and it was recommended that school teachers and students,especially children of lower school age should receive seasonal influenza vaccination as early as possible.
Influenza A(H1N1)OutbreakSchoolInvestigation and analysis
万方数据
维普
