Epidemiological Analysis of the Outbreaks of A /H1N1 Influenza in Schools in Guangzhou

Objective To analyze epidemiological characteristic of A /H1N1 influenza outbreaks in school in Guangzhou,so as to provide reference for prevention and control in school.Methods Descriptive epidemiology and statistic analysis were utilized to study onset time and clinical symptoms of confirmed cases and its initial source,control methods of A /H1N1 influenza outbreaks in school.Results A total of 8 school outbreaks of A /H1N1 influenza took place in 6 districts in Guangzhou,and attack rate was 0.52%.The school outbreaks were mainly occurred in late June,average time interval between two outbreaks was 2.13 days,with duration of 6 days.The outbreaks in college took biggest proportion(62.5%).Among 46 confirmed cases,males and females were equal,the mean age of confirmed cases was 16.85 years old,67.39% aged from 16 to 19 years old.About 60.87% and 30.43% of cases were founded by outbreak survey and via tracking close contacts of confirmed cases respectively.Among 8 school outbreaks of A /H1N1 influenza,two were secondary cases that resulted from confirmed A /H1N1 influenza patients,another 6 were brought out from indigenous community infection.It showed that there were significant correlation between the interval time from detecting initial case to taking control measures and time of outbreaks(r=0.932,P=0.001).Conclusion School should be focus of prevention and control of outbreaks of A /H1N1 influenza in Guangzhou in future.It is urgent to strengthen follow-up works,such as epidemic surveillance in school,training and education about knowledge of prevention and control A /H1N1 influenza and vaccination propaganda.