title: Prevalence and clinical features of respiratory syncytial virus in children hospitalized for community-acquired pneumonia in northern Brazil.
abstract: BACKGROUND
  Childhood pneumonia and bronchiolitis is a leading cause of illness and death in young children worldwide with Respiratory Syncytial Virus (RSV) as the main viral cause. RSV has been associated with annual respiratory disease outbreaks and bacterial co-infection has also been reported. This study is the first RSV epidemiological study in young children hospitalized with community-acquired pneumonia (CAP) in Belém city, Pará (Northern Brazil).
  
  
  METHODS
  With the objective of determining the prevalence of RSV infection and evaluating the patients' clinical and epidemiological features, we conducted a prospective study across eight hospitals from November 2006 to October 2007. In this study, 1,050 nasopharyngeal aspirate samples were obtained from hospitalized children up to the age of three years with CAP, and tested for RSV antigen by direct immunofluorescence assay and by Reverse Transcription Polymerase Chain Reaction (RT-PCR) for RSV Group identification.
  
  
  RESULTS
  RSV infection was detected in 243 (23.1%) children. The mean age of the RSV-positive group was lower than the RSV-negative group (12.1 months vs 15.5 months, p<0.001) whereas gender distribution was similar. The RSV-positive group showed lower means of C-reactive protein (CRP) in comparison to the RSV-negative group (15.3 vs 24.0 mg/dL, p<0.05). Radiological findings showed that 54.2% of RSV-positive group and 50.3% of RSV-negative group had interstitial infiltrate. Bacterial infection was identified predominantly in the RSV-positive group (10% vs 4.5%, p<0.05). Rhinorrhea and nasal obstruction were predominantly observed in the RSV-positive group. A co-circulation of RSV Groups A and B was identified, with a predominance of Group B (209/227). Multivariate analysis revealed that age under 1 year (p<0.015), CRP levels under 48 mg/dL (p<0.001) and bacterial co-infection (p<0.032) were independently associated with the presence of RSV and, in the analyze of symptoms, nasal obstruction were independently associated with RSV-positive group (p<0.001).
  
  
  CONCLUSIONS
  The present study highlights the relevance of RSV infection in hospitalized cases of CAP in our region; our findings warrant the conduct of further investigations which can help design strategies for controlling the disease.
authors.affiliation: Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brazil.
authors.forename: Letícia Martins
authors.initials: LM
authors.lastname: Lamarão
authors.forename: Francisco Luzio
authors.initials: FL
authors.lastname: Ramos
authors.forename: Wyller Alencar
authors.initials: WA
authors.lastname: Mello
authors.forename: Mirleide Cordeiro
authors.initials: MC
authors.lastname: Santos
authors.forename: Luana Soares
authors.initials: LS
authors.lastname: Barbagelata
authors.forename: Maria Cleonice Aguiar
authors.initials: MC
authors.lastname: Justino
authors.forename: Alexandre Ferreira
authors.initials: AF
authors.lastname: da Silva
authors.forename: Ana Judith Pires Garcia
authors.initials: AJ
authors.lastname: Quaresma
authors.forename: Veronilce Borges
authors.initials: VB
authors.lastname: da Silva
authors.forename: Rommel Rodríguez
authors.initials: RR
authors.lastname: Burbano
authors.forename: Alexandre Costa
authors.initials: AC
authors.lastname: Linhares
mesh_terms: D001938:Brazil / Q000453:epidemiology; D002673:Child, Hospitalized; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000473:pathology* / Q000821:virology*; D003430:Cross-Sectional Studies; D005260:Female; D019085:Fluorescent Antibody Technique, Direct; D006801:Humans; D007223:Infant; D008297:Male; D009305:Nasopharynx / Q000821:virology; D011024:Pneumonia, Viral / Q000453:epidemiology / Q000473:pathology* / Q000821:virology*; D015995:Prevalence; D011446:Prospective Studies; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology / Q000473:pathology* / Q000821:virology*; D018113:Respiratory Syncytial Virus, Human / Q000302:isolation & purification*; D020133:Reverse Transcriptase Polymerase Chain Reaction