title: Characterization of rotavirus and norovirus strains: a 6-year study (2004-2009).
abstract: OBJECTIVE
  To monitor rotavirus (RV) and norovirus (NoV) infections in hospitalized children ≤ 5 years with acute gastroenteritis in the state of São Paulo, Brazil, during a 6-year period (2004- 2009).
  
  
  METHODS
  This retrospective study was conducted with 61 medical centers with convenient surveillance fecal specimens, investigated by enzyme-linked immunosorbent assay, sodium dodecyl sulfate polyacrylamide gel electrophoresis, reverse polymerase chain reaction and sequencing to genotype characterization.
  
  
  RESULTS
  RV and NoV infections were detected in 29.6% (144/487) and 29.2% (26/89) of the samples, respectively. The most frequent RV genotypes detected were G9P[8] in 2004; G1P[8] in 2005; G9P[8] in 2006; and G2P[4] during 2007, 2008, and 2009. Detection rate declined from 36.3% (33/91) in 2004 to 4.2% (4/95) in 2009. NoV genogroup GII was found in 61.6% (16/26) of the samples, and GI in 11.5% (3/26). Mixed NoV-RV infections were observed in 2.2% (2/89) of the samples, involving GI+G9P[8] and GI+G2P[4] strains.
  
  
  CONCLUSIONS
  Genotype distribution varied according to collection year, accompanied by a reduction in detection rate. Use of RV vaccine requires implementation of post-marketing surveillance to monitor RV strain diversity and its efficacy against possible new emerging genotypes. NoVs have been increasingly identified as relevant etiological agents among hospitalized children and play an important role in the viral etiology of pediatric acute gastroenteritis in the state of São Paulo.
authors: Enteric Disease Laboratory, Virology Center, Instituto Adolfo Lutz, São Paulo, SP, Brazil. audreycilli@gmail.com
authors: Audrey
authors: A
authors: Cilli
authors: Adriana
authors: A
authors: Luchs
authors: Simone G
authors: SG
authors: Morillo
authors: Fernanda F
authors: FF
authors: Costa
authors: Rita de Cássia C
authors: Rde C
authors: Carmona
authors: Maria do Carmo S T
authors: Mdo C
authors: Timenetsky
mesh_terms: D001938:Brazil / Q000453:epidemiology; D017250:Caliciviridae Infections / Q000453:epidemiology / Q000821:virology*; D002675:Child, Preschool; D005243:Feces / Q000821:virology; D005759:Gastroenteritis / Q000453:epidemiology / Q000821:virology*; D005838:Genotype; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D029322:Norovirus / Q000235:genetics / Q000302:isolation & purification*; D012189:Retrospective Studies; D012401:Rotavirus / Q000235:genetics / Q000302:isolation & purification*; D012400:Rotavirus Infections / Q000453:epidemiology / Q000821:virology*; D017423:Sequence Analysis, RNA; D013997:Time Factors