title: Viral etiology of community-acquired pneumonia among adolescents and adults with mild or moderate severity and its relation to age and severity.
abstract: BACKGROUND
  Better knowledge of distribution of respiratory viruses (RVs) in adolescents and adults with community-acquired pneumonia (CAP) is needed.
  
  
  METHODS
  To investigate the RVs etiology among adolescents and adults with CAP, according to age and pneumonia severity index (PSI), a multi-center, prospective study was conducted from November 2010 to April 2012. Fifteen RVs were tested by polymerase chain reaction (PCR). Bacteria were detected by urinary antigen, conventional culture and PCR.
  
  
  RESULTS
  Mean (SD) age and median (IQR) PSI score of 954 patients enrolled was 45.2 (19.5) years (range 14-94) and 42 (36). RVs were found in 262 patients (27.5%): influenza virus A (IFV A, 9.9%) comprised of pandemic H1N1 (6.7%) and seasonal H3N2 (3.5%), human rhinovirus (4.3%), adenovirus (4.2%), human metapneumovirus (1.8%), parainfluenza virus 1, 3 and 2 (1.7%, 1.5% and 1.2%). Influenza virus B, enterovirus, respiratory syncytial virus, human coronavirus and parainfluenza virus 4 were rarely detected (<1%). Frequency of IFV A was highest among patients aged between 45-64 years (p < 0.001), while adenovirus among patients aged 14-17 years (p < 0.001), no differences was found in other RVs. The proportion of pandemic H1N1 increased with severity of pneumonia evaluated by PSI (P < 0.05).
  
  
  CONCLUSIONS
  The proportion of RVs in CAP is higher than previously reported. IFV A pneumonia are usually found in patients older than 45 years, while, adenovirus pneumonia are common in adolescents and young adults. Pandemic H1N1 virus is still recognized by PSI as a high-severity pathogen. The findings contribute baseline data on viral CAP study in China.
authors: Jiu-Xin
authors: JX
authors: Qu
authors: Li
authors: L
authors: Gu
authors: Zeng-Hui
authors: ZH
authors: Pu
authors: Xiao-Min
authors: XM
authors: Yu
authors: Ying-Mei
authors: YM
authors: Liu
authors: Ran
authors: R
authors: Li
authors: Yi-Min
authors: YM
authors: Wang
authors: Bin
authors: B
authors: Cao
authors: Chen
authors: C
authors: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002681:China / Q000453:epidemiology; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000382:microbiology / Q000821:virology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011024:Pneumonia, Viral / Q000453:epidemiology* / Q000382:microbiology / Q000821:virology*; D011446:Prospective Studies; D012720:Severity of Illness Index; D055815:Young Adult