title: [Virus spectrum features of adult influenza-like fever in outpatients].
abstract: OBJECTIVE
  To analyze the results of detection on respiratory virus of influenza-like illness ( ILI ) in Beijing from June 2010 to February 2012 and understand the virus spectrum of adult influenza-like fever.
  
  
  METHODS
  A total of 502 swabs were collected and 279 throat swabs tested for 12 respiratory viruses with multiplex reverse transcription-polymerase chain reaction (RT-PCR). And 413 swabs were tested for pH1N1 by virus isolation influenza viruses. And the data were statistically analyzed.
  
  
  RESULTS
  One or two viruses were detected in 26.9% (75/279) of the samples. Influenza A virus (FLU-A) accounted for 85.3% of positive samples and 22.9% (64/279) of ILI tested. The positive rate of other viruses was less than 3.0 %. The positive rates among the following subtypes were: 2.7% (11/413) for pH1N1, 2.4% (10/413) for H3 and 6.5% (27/413) for FLU-B. FLU-A was the predominant virus during the 2010-2011 influenza season and the positive rate peaked in January 2011 in Beijing and north China. FLU-B was the primary virus during the 2011-2012 influenza season and the positive rate peaked in January and February 2012. There was a significant reduction in the incidence of ILI in 2010 and 2011 when compared with 2009. During the 2009-2012 influenza seasons, the incidence peaked in December 2009, January 2011 and January and February 2012 in Beijing.
  
  
  CONCLUSIONS
  Exposure to pH1N1 had no impact on typical influenza seasonal peaks. Influenza virus was the predominant virus of adult influenza-like fever cases after the pandemic period of influenza A (H1N1) 2009 and the positive rate peaked in January and February during the 2009-2012 influenza seasons.
authors.affiliation: Peking University People's Hospital, Peking University Hepatology Institute, Department of Infectious Disease, Beijing 100044, China.
authors.forename: Xiao-hua
authors.initials: XH
authors.lastname: Yang
authors.forename: Mei-fang
authors.initials: MF
authors.lastname: Chen
authors.forename: Yan
authors.initials: Y
authors.lastname: Gao
authors.forename: Meng
authors.initials: M
authors.lastname: Xi
authors.forename: Xia
authors.initials: X
authors.lastname: Yang
authors.forename: Xiao-lin
authors.initials: XL
authors.lastname: Guo
authors.forename: Chun-ling
authors.initials: CL
authors.lastname: Sun
authors.forename: Jian-ying
authors.initials: JY
authors.lastname: Zhu
authors.forename: Yan-di
authors.initials: YD
authors.lastname: Xie
authors.forename: Ya-fen
authors.initials: YF
authors.lastname: Liu
authors.forename: Lai
authors.initials: L
authors.lastname: Wei
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002681:China / Q000453:epidemiology; D005334:Fever / Q000821:virology*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000302:isolation & purification*; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology*; D008875:Middle Aged; D055815:Young Adult