title: Rotavirus epidemiology before and after vaccine introduction.
abstract: OBJECTIVE
  To evaluate the prevalence and circulation of rotavirus genotypes before and after the introduction of oral vaccine against human rotavirus, and to check for a possible change in the age of occurence of the infection by RV-A.
  
  
  METHODS
  This was a cross-sectional study conducted between 2002-2011, in the city of Juiz de Fora, state of Minas Gerais, Brazil. A total of 1,144 diarrheal stool specimens were obtained from nonhospitalized children aged between 0 and 5 years, and analyzed by polyacrylamide gel electrophoresis and reverse-transcription polymerase chain reaction for genotype characterization. Data on prevalence and age distribution of rotavirus cases were analyzed through the chi-squared test (p < 0.05), using SPSS, release 13.0.
  
  
  RESULTS
  Rotavirus infection was detected in 9.35% (107/1,144) samples, with prevalence rates ranging from 11.12% (90/809) in the pre-vaccine to 5.07% (17/335) in the post-vaccine period (p = 0.001). Among the samples tested, the most frequently detected genotypes were G1P[6] (6/33 = 18.2%) in the period between 2002 and 2005 and G2P[4] in 2006 (11/33 = 33.3%) and in the period between 2007 and 2011 (5/33 = 15.2%). There was also a significant reduction in the number of cases of rotavirus disease in children aged between 0 and 36 months after the vaccine introduction.
  
  
  CONCLUSIONS
  The study evidenced a significant decrease in the prevalence of rotavirus, mainly in children aged between 0 and 36 months in the 2007-2011 period, as well as a reduction in G1 genotype circulation.
authors.affiliation: Master's Degree in Biological Sciences, Universidade Federal de Juiz de Fora (UFJF), Juiz de Fora, MG, Brazil.
authors.forename: Andrêssa S F
authors.initials: AS
authors.lastname: Assis
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Valle
authors.forename: Gustavo R
authors.initials: GR
authors.lastname: Antunes
authors.forename: Sandra H C
authors.initials: SH
authors.lastname: Tibiriça
authors.forename: Rosane Maria S de
authors.initials: RM
authors.lastname: Assis
authors.forename: José Paulo G
authors.initials: JP
authors.lastname: Leite
authors.forename: Iná P de
authors.initials: IP
authors.lastname: Carvalho
authors.forename: Maria Luzia da
authors.initials: ML
authors.lastname: Rosa e Silva
mesh_terms: D000367:Age Factors; D017668:Age of Onset; D001938:Brazil / Q000453:epidemiology; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005243:Feces / Q000821:virology; D005260:Female; D005838:Genotype; D062489:Health Impact Assessment / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D008297:Male; D032541:Mass Vaccination / Q000592:standards; D015995:Prevalence; D012367:RNA, Viral / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012401:Rotavirus / Q000302:isolation & purification*; D012400:Rotavirus Infections / Q000453:epidemiology* / Q000821:virology; D022243:Rotavirus Vaccines / Q000627:therapeutic use*
chemical_list: D012367:RNA, Viral; D022243:Rotavirus Vaccines
keywords: Epidemiologia; Epidemiology; Genotypes; Genótipos; Rotavirus; Rotavirus vaccines; Rotavírus; Vacinas contra rotavírus