title: Genetic diversity and clinical impact of human rhinoviruses in hospitalized and outpatient children with acute respiratory infection, Argentina.
abstract: BACKGROUND
  Human rhinoviruses (HRV) are recognized as a cause of upper and lower acute respiratory infections (ARI). The circulating species and their clinical impact were not described in Argentina.
  
  
  OBJECTIVE
  To describe the molecular epidemiology of HRV in children and to determine the association of HRV species with outcome and severity.
  
  
  METHODS
  Hospitalized and outpatients children <6 years old with ARI without comorbidities (n=620) were enrolled (2008-2010). Demographic, clinical data and outcome were analyzed. HRV were identified by RT-PCR. Phylogenetic analysis and demographic reconstruction for HRV were performed in selected samples.
  
  
  RESULTS
  HRV were detected in 252/620 (40.6%) of children; 8.5% in viral coinfection. Bronchiolitis (55%) and pneumonia (13%) were the most frequent clinical diagnosis. Of 202 inpatients with HRV: 72% required oxygen supplementation, 11% intensive care unit and 3% mechanical ventilation. HRV were identified as a risk factor for hospitalization (OR: 2.47). All three HRV species were detected being HRV-A (55%) and HRV-C (43%) the most frequent; HRV-B was infrequent (2%). Of 44 sequenced HRV, 30 genotypes were detected. Seven of them were the most prevalent and circulated during limited periods of time. The demographic reconstruction revealed a constant population size and a high turnover rate of genotypes. Demographic and clinical outcome were similar for HRV-A and HRV-C infections.
  
  
  CONCLUSIONS
  This study highlights the clinical impact of HRV in children without comorbidities as a cause of lower ARI and hospitalization. The high frequency of HRV infections may be associated with the simultaneous circulation of genotypes and their high turnover rate.
authors.affiliation: Virology Unit and Clinical Virology Laboratory, Hospital Universitario CEMIC, Av. Galván 4102, Buenos Aires, Argentina. Electronic address: deboramarcone@hotmail.com.
authors.forename: Débora Natalia
authors.initials: DN
authors.lastname: Marcone
authors.affiliation: Department of Virology, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 954, Buenos Aires, Argentina.
authors.forename: Andrés
authors.initials: A
authors.lastname: Culasso
authors.affiliation: Virology Unit and Clinical Virology Laboratory, Hospital Universitario CEMIC, Av. Galván 4102, Buenos Aires, Argentina.
authors.forename: Guadalupe
authors.initials: G
authors.lastname: Carballal
authors.affiliation: Department of Virology, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 954, Buenos Aires, Argentina.
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Campos
authors.affiliation: Virology Unit and Clinical Virology Laboratory, Hospital Universitario CEMIC, Av. Galván 4102, Buenos Aires, Argentina.
authors.forename: Marcela
authors.initials: M
authors.lastname: Echavarría
mesh_terms: D001118:Argentina; D002675:Child, Preschool; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007223:Infant; D007297:Inpatients; D008297:Male; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010045:Outpatients; D010802:Phylogeny; D010850:Picornaviridae Infections / Q000473:pathology* / Q000821:virology*; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D012141:Respiratory Tract Infections / Q000473:pathology* / Q000821:virology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012229:Rhinovirus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D016896:Treatment Outcome
chemical_list: D012367:RNA, Viral
keywords: Acute respiratory infection; Children; Genotypes; Human rhinoviruses; Molecular epidemiology