title: Prevalence of infection with cagA-positive Helicobacter pylori strains among children and adolescents in southern Brazil.
abstract: BACKGROUND
  Helicobacter pylori (H. pylori) has a worldwide distribution, but the prevalence of infection, virulence factors, and clinical presentation vary widely according to the studied population. In Brazil, a continental country composed of several ethnicities and cultural habits, the behavior of infection also appears to vary, as many other studies have shown.
  
  
  OBJECTIVE
  Describe the prevalence of infection with cagA-positive H. pylori strains in a group of children and adolescents who underwent esophagogastroduodenoscopy in Porto Alegre, Rio Grande do Sul.
  
  
  METHODS
  Fifty-four gastric biopsy specimens of children and adolescents with H. pylori infection demonstrated by histology, urease test and molecular analysis were tested for the presence of cagA positive H. pylori strains by the polymerase chain reaction method.
  
  
  RESULTS
  The prevalence of cagA-positive H. pylori was 29.6% (95% confidence interval, 18 to 43.6%). There were no statistically significant differences in clinical or demographic characteristics or in the endoscopic and histological features of patients infected with cagA-positive strains as compared with those infected by cagA-negative strains.
  
  
  CONCLUSIONS
  he study showed a low prevalence of infection with cagA-positive H. pylori strains among children and adolescents who underwent EGD in southern Brazil, in comparison to studies conducted with children from other regions of Brazil. There was no association between the presence of cagA-positive strains and more severe clinical presentations in the studied sample.
authors.affiliation: Programa de Pós Graduação em Saúde da Criança e do Adolescente, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul - UFRGS, Porto Alegre, RS, Brasil.
authors.forename: Juliana Ghisleni de
authors.initials: JG
authors.lastname: Oliveira
authors.affiliation: Programa de Pós Graduação em Saúde da Criança e do Adolescente, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul - UFRGS, Porto Alegre, RS, Brasil.
authors.forename: Cristina Helena Targa
authors.initials: CH
authors.lastname: Ferreira
authors.affiliation: Laboratório Amplicon, Porto Alegre, RS, Brasil.
authors.forename: Anna Carolina Saraiva
authors.initials: AC
authors.lastname: Camerin
authors.affiliation: Programa de Pós Graduação em Saúde da Criança e do Adolescente, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul - UFRGS, Porto Alegre, RS, Brasil.
authors.forename: Cláudia Augustin
authors.initials: CA
authors.lastname: Rota
authors.affiliation: Departamento de Patologia, Hospital de Clínicas de Porto Alegre e Medicina Digital, Porto Alegre, RS, Brasil.
authors.forename: Luíse
authors.initials: L
authors.lastname: Meurer
authors.affiliation: Programa de Pós Graduação em Saúde da Criança e do Adolescente, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul - UFRGS, Porto Alegre, RS, Brasil.
authors.forename: Themis Reverbel da
authors.initials: TR
authors.lastname: Silveira
mesh_terms: D000293:Adolescent; D000942:Antigens, Bacterial / Q000235:genetics / Q000302:isolation & purification*; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification*; D001938:Brazil / Q000453:epidemiology; D002648:Child; D003430:Cross-Sectional Studies; D016145:Endoscopy, Digestive System / Q000379:methods; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D015995:Prevalence; D013272:Stomach Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology*
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori