Surveillance and analysis on influenza in Longgang District of Shenzhen City from 2010-2011

[Objective]To analyze the surveillance results of influenza in Longgang District of Shenzhen City in Guangdong,provide the reference for developing influenza prevention and control strategies.[Methods]The epidemiological,etiological and serological surveillance data of influenza-like illness cases in Longgang District from 2010-2011 were analyzed to explore the epidemic pattern.[Results]A total of 55 429 influenza-like illness cases were reported in Longgang District from 2010-2011,accounting for 7.24%(55 429/765 910) of the total outpatient cases.Most of cases were children under 15 years old,accounting for 80.55%.The influenza-like illness cases occurred all the year round.During the two years,a total of 312 strains of influenza viruses were isolated with the positive rate of 38.61%(312 /808),including 96 strains of seasonal influenza A viruses and 113 strains of B viruses,103 strains of influenza A H1N1.43 influenza outbreaks occurred in two years,with 458 cases accumulatively.Most outbreaks occurred during March-May and December,which accounted for 83.72%,and all influenza outbreaks occurred in schools and nurseries.The influenza A viruses was predominant in outbreaks of both 2010(94.44%) and 2011(76.00%).[Conclusion]The epidemic situation of seasonal influenza in Longgang District from 2010-2011 is relatively stable without large-scale outbreaks,and no significant virus variation is observed.