Surveillance and analysis of influenza outbreaks in children in Guangzhou during 2015-2016

Objective To analyze the epidemiological characteristics of influenza epidemic in Guangzhou,and to provide scientific evidence for influenza prevention and control.Methods From 2015 to 2016,throat swab samples from children infected influenza epidemic in Guangzhou were collected.Fluorescent quantitative RT-PCR was used for detection of influenza virus.SPSS 11 software was used for statistical analysis.Results Influenza B had the highest detection rate (23.57%) in the 3 259 samples.There were 25 outbreaks of influenza viruses with different types or subtypes of influenza viruses,accounting for 12.02% (25/208).There was obvious seasonal characteristics,and each year had both highest and lowest season peak.The highest peak occurred from March to July and the lowest peak occurred from November to December.The peak season was mainly caused by influenza B,accompanied by H3N2 and H1N1 alternately.The highest positive rate of influenza detection was among 9-10-year-old children 39.33%.Boys were higher than that of girls.The detection rate of influenza epidemic in primary schools was the highest,with an average positive rate of 34.88%.Conclusion The epidemic of children's influenza in Guangzhou shows seasonal pattern.Influenza B viruses become the predominant circulating influenza virus.Children,especially grade 2 and grade 3,in primary schools are a key link in the transmission of influenza.