title: Respiratory viruses in bronchoalveolar lavage: a hospital-based cohort study in adults.
abstract: BACKGROUND
  The epidemiology of respiratory viruses and their potential clinical impact when recovered in lower respiratory specimens has not been established in the hospital setting. A study was performed to investigate the association between positive viral detection and respiratory infection in an at-risk population.
  
  
  METHODS
  299 adult patients who underwent bronchoalveolar lavage (BAL) procedures were enrolled in a hospital-based prospective cohort study. Descriptive epidemiology is presented of 17 different respiratory viruses detected by reverse transcription-polymerase chain reaction assays in BAL fluid specimens. Multivariate analysis was conducted to identify the clinical characteristics independently associated with the presence of virus.
  
  
  RESULTS
  Of 522 BAL fluid specimens analysed, 81% were collected in adult transplant recipients or other immunocompromised patients. Overall, PCR assays identified viral nucleic acid in 91 BAL fluid samples (17.4%). Similar rates of virus-positive BAL fluid were found in the different subpopulations studied (p = 0.113). Coronaviruses were the most frequent (32.3%), followed by rhinovirus (22.6%), parainfluenza (19.5%), influenza (9.7%), respiratory synctial virus (8.6%), human metapneumovirus (4.2%) and bocavirus (3.1%). Multivariate analysis using mixed models showed that respiratory viral infections were associated with a lack of antibiotic treatment response (OR 2.2, 95% CI 1.2 to 4.1) and the absence of radiological infiltrate (OR 0.3, 95% CI 0.2 to 0.8). In lung transplant recipients in whom a respiratory infection was suspected, the respiratory viral detection rate was 24.4% compared with 13.8% overall in other patients (p = 0.02).
  
  
  CONCLUSIONS
  In this cohort of hospitalised adults, respiratory viruses detected in BAL fluid specimens were associated with respiratory symptoms, absence of radiological infiltrates and a poor response to antibiotic therapy.
authors.affiliation: University Hospitals of Geneva, Switzerland. jorge.garbino@hcuge.ch
authors.forename: J
authors.initials: J
authors.lastname: Garbino
authors.forename: P M
authors.initials: PM
authors.lastname: Soccal
authors.forename: J-D
authors.initials: JD
authors.lastname: Aubert
authors.forename: T
authors.initials: T
authors.lastname: Rochat
authors.forename: P
authors.initials: P
authors.lastname: Meylan
authors.forename: Y
authors.initials: Y
authors.lastname: Thomas
authors.forename: C
authors.initials: C
authors.lastname: Tapparel
authors.forename: P-O
authors.initials: PO
authors.lastname: Bridevaux
authors.forename: L
authors.initials: L
authors.lastname: Kaiser
mesh_terms: D001992:Bronchoalveolar Lavage Fluid / Q000821:virology*; D015331:Cohort Studies; D003428:Cross Infection / Q000821:virology*; D005260:Female; D006760:Hospitalization; D006801:Humans; D016040:Lung Transplantation; D008297:Male; D008875:Middle Aged; D009894:Opportunistic Infections / Q000175:diagnosis* / Q000821:virology; D012141:Respiratory Tract Infections / Q000175:diagnosis / Q000821:virology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012621:Seasons; D014777:Virus Diseases / Q000175:diagnosis / Q000821:virology*; D014780:Viruses / Q000302:isolation & purification*