Detection characteristics of the virus during school influenza outbreaks in Linyi City
Objective To analyze the characteristics of influenza virus detection in an influenza outbreak in schools,so as to provide a strategic basis for the treatment of influenza outbreaks in schools.Methods A total of 1 702 samples were collected from 52 school influenza outbreaks reported in Linyi City in 2021-2022.The samples were divided into 3 types according to different symptoms during the management of the epidemic[group A:influenza-like illness(ILI)group;group B:mild illness group;group C:close contacts group].Rt-PCR was used to detect influenza virus nucleic acid in the collected samples.The detection rate of in-fluenza virus in the outbreaks was analyzed by x2 test.Results In total,1 071 samples(62.93%)tested positive for influenza virus nucleic acid.Among them,610 out of 726 samples(84.02%)were detected in group A,while 331 out of 634 samples(52.21%)were detected in group B.In group C,130 out of 342 samples(38.01%)tested positive.The differences were statistically signifi-cant(X2=260.71,P<0.01).In group A,males had a detection rate of 80.83%for influenza virus nucleic acid,compared to 91.36%for females.For group B,the rates were 53.31%for males and 50.87%for females.In group C,males had a rate of 30.72%,while females had a rate of 43.92%.Statistical significance for gender differences was observed only in groups A and C(X2=12.67,6.25,P<0.05).According to the days of onset,the detection rates of influenza virus nucleic acid among patients with onset 0-6 days were 56.30%,74.49%,89.35%,86.23%,69.67%,62.75%,34.33%,respectively,and the difference was sta-tistically significant(X2=128.27,P<0.01).Conclusions Mild cases and close contacts are likely key factors contributing to the prolonged emergence of new cases within classrooms during school influenza outbreaks.The progression of influenza symptoms is re-lated to the risk of transmission.
Influenza,humanDisease outbreaksVirusesStudent health services