title: Viral infection in community-acquired pneumonia: a systematic review and meta-analysis.
abstract: The advent of PCR has improved the identification of viruses in patients with community-acquired pneumonia (CAP). Several studies have used PCR to establish the importance of viruses in the aetiology of CAP.We performed a systematic review and meta-analysis of the studies that reported the proportion of viral infection detected via PCR in patients with CAP. We excluded studies with paediatric populations. The primary outcome was the proportion of patients with viral infection. The secondary outcome was short-term mortality.Our review included 31 studies. Most obtained PCR via nasopharyngeal or oropharyngeal swab. The pooled proportion of patients with viral infection was 24.5% (95% CI 21.5-27.5%). In studies that obtained lower respiratory samples in >50% of patients, the proportion was 44.2% (95% CI 35.1-53.3%). The odds of death were higher in patients with dual bacterial and viral infection (OR 2.1, 95% CI 1.32-3.31).Viral infection is present in a high proportion of patients with CAP. The true proportion of viral infection is probably underestimated because of negative test results from nasopharyngeal or oropharyngeal swab PCR. There is increased mortality in patients with dual bacterial and viral infection.
authors.affiliation: Division of Pulmonary, Critical Care and Sleep Medicine, University of Louisville, Louisville, KY, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Burk
authors.affiliation: Division of Pulmonary, Critical Care and Sleep Medicine, University of Louisville, Louisville, KY, USA.
authors.forename: Karim
authors.initials: K
authors.lastname: El-Kersh
authors.affiliation: Division of Pulmonary, Critical Care and Sleep Medicine, University of Louisville, Louisville, KY, USA.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Saad
authors.affiliation: Division of Infectious Diseases, University of Louisville, Louisville, KY, USA.
authors.forename: Timothy
authors.initials: T
authors.lastname: Wiemken
authors.affiliation: Division of Infectious Diseases, University of Louisville, Louisville, KY, USA.
authors.forename: Julio
authors.initials: J
authors.lastname: Ramirez
authors.affiliation: Division of Pulmonary, Critical Care and Sleep Medicine, University of Louisville, Louisville, KY, USA rodrigo.cavallazzi@louisville.edu.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Cavallazzi
mesh_terms: D000328:Adult; D000368:Aged; D017714:Community-Acquired Infections / Q000175:diagnosis / Q000401:mortality / Q000628:therapy / Q000821:virology*; D004279:DNA, Viral / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009305:Nasopharynx / Q000821:virology; D016017:Odds Ratio; D009960:Oropharynx / Q000821:virology; D011024:Pneumonia, Viral / Q000175:diagnosis / Q000401:mortality / Q000628:therapy / Q000821:virology*; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D011379:Prognosis; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014780:Viruses / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity
chemical_list: D004279:DNA, Viral