title: Acute respiratory infection by human metapneumovirus in children in southern Brazil.
abstract: BACKGROUND
  Human metapneumovirus (hMPV) has been described as an etiologic agent of acute respiratory infections (ARI), mainly in pediatric patients. Viral isolation is difficult and has low sensitivity, and consequently RT-PCR assays are currently used for detection.
  
  
  OBJECTIVE
  Detect hMPV in ARI in hospitalized children in Southern Brazil; standardize a RT-PCR for routine hMPV diagnosis; validate a positive control for molecular tests; and perform phylogenetics analyses.
  
  
  METHODS
  Nasopharyngeal aspirates (NPA) from 156 hospitalized children were studied. A conserved region of the nucleoprotein gene was cloned, characterized and used to standardize an RT-PCR assay. Phylogenetic analyses were performed. Clinical data were obtained from medical records.
  
  
  RESULTS
  hMPV was detected in 6.4% of the samples. Dyspnea and wheezing were frequently reported symptoms and the most common diagnoses were bronchiolitis, acute respiratory insufficiency or laryngotracheobronchitis. Nucleotide sequence alignment revealed 97.7% identity with genotype A1 of hMPV. The detection limit of hMPV genomes by RT-PCR in clinical samples was 180 copies/microL.
  
  
  CONCLUSIONS
  This is the first report of the detection and genetic characterization of hMPV infections in children with lower ARI in Southern Brazil.
authors.affiliation: Laboratório de Virologia, Hospital de Clínicas da Universidade Federal do Paraná, Brazil.
authors.forename: Maria
authors.initials: M
authors.lastname: do Carmo Debur
authors.forename: Juliano
authors.initials: J
authors.lastname: Bordignon
authors.forename: Claudia Nunes
authors.initials: CN
authors.lastname: Duarte dos Santos
authors.forename: Luine Rosele
authors.initials: LR
authors.lastname: Vidal
authors.forename: Meri Bordignon
authors.initials: MB
authors.lastname: Nogueira
authors.forename: Sérgio Monteiro
authors.initials: SM
authors.lastname: de Almeida
authors.forename: Sonia Mara
authors.initials: SM
authors.lastname: Raboni
mesh_terms: D000208:Acute Disease; D001938:Brazil; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D029121:Metapneumovirus / Q000235:genetics / Q000302:isolation & purification*; D009305:Nasopharynx / Q000821:virology; D018184:Paramyxoviridae Infections / Q000821:virology*; D010802:Phylogeny; D015203:Reproducibility of Results; D012141:Respiratory Tract Infections / Q000821:virology*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*