Epidemiological characteristics of 2009 pandemic influenza A (H1NI) in Daxing district, Beijing.

Objective To analyze the epidemiological characteristics of 2009 pandemic influenza A(H1N1) in Daxing district,Beijing,and provide scientific basis for the disease prevention and control in future.Methods The influenza H1N1 cases were confirmed between June,2009 and January,2010 in Daxing District,Beijing.Descriptive epidemiological methods were used to analyze the characteristics of pandemic influenza A(H1N1).Results 403 influenza A(H1N1) cases were detected and strain typed by real-time RT-PCR.The average time was 3 days(3.16±1.99) from the onset of disease to diagnosis.The most reported symptoms were fever,cough and sore throat.The mortality rate was 1.7%(7/403).There was no significant sex difference of patients(women: 53.35%;men: 46.65%).39.21% of the cases were students.The peak of incidences appeared on November 2009,which had 40.45% of total confirmed cases.76.67% of cases occurred in the suburb areas of the district.There was an obvious curve of incidences from introduction of the influenza,dissemination of virus,to peak occurrence,and then the decline of the pandemic,which took about 6 months.Conclusion The high efficient control methods taken during the epidemic period decreased the morbidity and mortality.