title: [Prevalence characteristics of influenza viruses in children in Beijing during 2014-2015 and 2015-2016 influenza seasons].
abstract: OBJECTIVE
  To compare the prevalence characteristics of influenza viruses in children in Beijing during 2014-2015 and 2015-2016 influenza seasons.
  
  
  METHODS
  Throat swabs were collected weekly from children with influenza-like illnesses who visited in Children's Hospital affiliated to Capital Institute of Pediatrics during the period from September 2014 to May 2016.Influenza viruses A and B viruses were detected by real-time RT-PCR, followed by identification of H3N2, H1N1pdm, B/Victoria-like and B/Yamagata-like.The prevalence characteristics of influenza viruses was estimated by means of descriptive statistics.The t test and chi-square test were used to compare median age and gender ratio of infected children among different types of influenza viruses.
  
  
  RESULTS
  Out of 1 821 throat swabs collected, 139 (7.6%) were positive for H3N2 and 43 (2.4%) for H1N1pdm and 204 (11.2%) for influenza B virus, including 108 for B/Victoria-like and 96 for B/Yamagata-like.The median age of H1N1pdm infected children ((3.3±2.2) years) was significantly younger than that of H3N2 ((4.7±3.2) years) and influenza B virus((4.9±2.8) years) (H1N1pdm vs. H3N2: t=2.848, P=0.002; H1N1pdm vs. influenza B, t=3.682, P=0.000). Two epidemic peaks were presented in 2014-2015 influenza season, dominated definitely by H3N2 and B/Yamagata-like, respectively, while one delayed peak started at the 51(st) week, 2015, co-circulated with H3N2, H1N1pdm and influenza B viruses, among which B/Victoria-like virus was predominant during the 2015-2016 season.
  
  
  CONCLUSIONS
  Prevalence characteristics of influenza viruses are different between 2014-2015 and 2015-2016 influenza seasonal epidemics in children in Beijing. It is important to monitor the genetic variations of influenza viruses and to keep close attention to influenza B virus as well as influenza A virus.
authors: Laboratory of Virology, Beijing Key Laboratory of Etiology of Viral Diseases in Children, Capital Institute of Pediatrics, Beijing 100020, China.
authors: Y
authors: Y
authors: Sun
authors: R N
authors: RN
authors: Zhu
authors: F
authors: F
authors: Wang
authors: J
authors: J
authors: Deng
authors: L Q
authors: LQ
authors: Zhao
authors: R
authors: R
authors: Tian
authors: Y
authors: Y
authors: Qian
mesh_terms: D000068476:Beijing / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D014644:Genetic Variation; D006801:Humans; D053122:Influenza A Virus, H3N2 Subtype; D009980:Influenza A virus; D009981:Influenza B virus; D007251:Influenza, Human / Q000453:epidemiology*; D008297:Male; D015995:Prevalence; D060888:Real-Time Polymerase Chain Reaction; D012621:Seasons