Abstract:

【Abstract】 Objective  To understand the epidemiological tendency of influenza A(H3N2) in Xingtai City from 2009 to 2014 for scientific evidence to prevent and control its spreading. Methods  Throat swab specimens were collected between June 2009 and May 2014 from patients presenting with influenza-like illness (ILI), and subjected to detection of the nucleic acid content of influenza A H3N2 viruses by real-time quantitative fluorescence PCR. The surveillance data obtained from June to the following May were statistically analyzed. Results  Throat swab specimens obtained in 1 391, 514, 643, 628 and 1 185 cases in respective five surveillance cycles were tested, and the positive rates were 6.25%(86/1 391), 7.60%(40/514), 0.31%(2/643), 7.32%(46/628) and 1.19%(14/1 185), respectively. The positive rate was fluctuated significantly in different cycles(χ2=93.728 P<0.01), and was dominated by January, March and September, yet the epidemic was free between April and August within a year. The specimens positive for influenza A(H3N2) virus were statistically different in different age group(χ2=44.595, P<0.01), and highest in the group of five years(7.94%). Conclusion  Influenza A(H3N2) was prevalent in yearly manner in Xintai City from 2009 to 2014, and its epidemic extended from September to following March and peaked between September and following January. However, surveillance needs strengthening in order to timely understand the epidemiological trend for scientific control of this communicable disease.

Key words: Influenza A(H3N2), Influenza, Real-time quantitative PCR