title: Respiratory virus is a real pathogen in immunocompetent community-acquired pneumonia: comparing to influenza like illness and volunteer controls.
abstract: BACKGROUND
  Viral pathogens were more commonly reported than previously estimated in community-acquired pneumonia (CAP) patients. However, the real role of virus was still controversial.
  
  
  METHODS
  Consecutive adult patients with CAP between April and December, 2009 were prospectively enrolled. A four-fold or greater increase of IgG-titres against respiratory viruses in pair sera was tested by means of hemagglutination inhibition assay or indirect immunofluorescence. Swab samples were tested by cell culture and/or nucleic amplification tests. Viral etiology was considered definitive if at least one of the above tests was positive.
  
  
  RESULTS
  Viral etiology was established in fifty-two (34.9%) of 149 CAP patients, twenty-two (81.5%) of 27 influenza like illness patients, and none of 75 volunteer controls. Forty-seven CAP patients were infected by a single virus (24 influenza A virus, 5 influenza B, 10 parainfluenza virus type 3 [PIV-3], 2 PIV-1, 2 adenovirus, 2 human rhinovirus and 2 coronavirus OC43), five cases by two or three viruses co-infection. Fever ≥ 39 °C (66.7%), fatigue (64.6%), and purulent sputum (52.1%) was the most common symptoms in viral pneumonia patients. On multivariate analysis, myalgia was included in the model for pneumonia associated with influenza infection. In the CURB-65 model only influenza infection was found independently associated with severe disease (CURB-65 score ≥ 3) out of variables, including age(years), sex, current smoking status, sick contact with febrile patients, numbers of comorbidity, presence of influenza infection, presence of PIV infection, with P = 0.021, OR 7.86 (95% CI 1.37-45.04).
  
  
  CONCLUSIONS
  Respiratory virus was not a bystander, but pathogenic in pneumonia and was a common cause of CAP.
authors.forename: Yangqing
authors.initials: Y
authors.lastname: Zhan
authors.forename: Zifeng
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Respiratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, State Key Laboratory of Respiratory Disease (Guangzhou Medical University, China), Guangzhou Institute of Respiratory disease, 151 Yanjiang Road, Guangzhou, PR, China. chenrc@vip.163.com.
authors.forename: Rongchang
authors.initials: R
authors.lastname: Chen
authors.forename: Yutao
authors.initials: Y
authors.lastname: Wang
authors.forename: Wenda
authors.initials: W
authors.lastname: Guan
authors.forename: Suishan
authors.initials: S
authors.lastname: Zhao
mesh_terms: D000256:Adenoviridae / Q000276:immunology; D000257:Adenoviridae Infections / Q000097:blood / Q000821:virology*; D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood*; D060085:Coinfection / Q000821:virology; D017714:Community-Acquired Infections / Q000097:blood / Q000821:virology; D017934:Coronavirus / Q000276:immunology; D018352:Coronavirus Infections / Q000097:blood / Q000821:virology; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D009980:Influenza A virus / Q000276:immunology; D009981:Influenza B virus / Q000276:immunology; D007251:Influenza, Human / Q000097:blood / Q000821:virology; D008297:Male; D008875:Middle Aged; D010222:Parainfluenza Virus 1, Human / Q000276:immunology; D010224:Parainfluenza Virus 3, Human / Q000276:immunology; D010850:Picornaviridae Infections / Q000097:blood / Q000821:virology; D011024:Pneumonia, Viral / Q000097:blood / Q000821:virology*; D011446:Prospective Studies; D012327:RNA Virus Infections / Q000097:blood / Q000821:virology*; D010253:Respirovirus Infections / Q000097:blood / Q000821:virology; D012229:Rhinovirus / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G