Analysis and survellance of influenza in Henan from 2009 to 2010

Objective To analysis epidemic characteristics and distribution of influenza virus subgroup in Henan from 2009 to 2010,and to provide bases for the prevention of influenza.Methods The data from national influenza surveillance net work were collected to analyze,the ILI throat swabs which nucleic acid test showed positive were collected for virus separation.Results The percentage of seeking the doctors of ILI was 5.1 % and 1.2 % in 2009 and 2010,and the peak of seeking for the doctors was November 2009.6 574 samples of ILI throat swabs were collected,and 220 influenza virus isolated with isolating rate for 3.3 %.The types of strains were main influenza A1 virus(57 trains) and A(H1N1) virus(104 trains),followed by influenza B(Victoria) virus(48 trains),the time of high-peak was in line with crest-time of seeking for doctors of ILI patients.Conclusion A1 and B(Victoria) virus was epidemic sequentially during the earlier months in 2009,the pandemic period of A(H1N1) began from August 2009 to January 2010,the pandemic peak of A(H1N1) dropped quickly during the time December 2009 to March 2010,but the prevalent trend of B(Victoria) gone up slightly.