title: Spontaneous elimination of Helicobacter pylori infection in a cohort of asymptomatic school children by enzyme-linked immunosorbent assay polyclonal antigen in stool.
abstract: OBJECTIVE
  To determine the natural evolution of the Helicobacter pylori infection through the fecal antigen of the H. pylori test in a cohort of school children during 2 consecutive years.
  
  
  BACKGROUND
  Studies have suggested that the spontaneous elimination rate is higher in developing countries, possibly owing to higher incidence rate.
  
  
  METHODS
  One hundred twelve children attending a day care center for the sons and daughters of university employees were evaluated yearly in a 2-year period using the H. pylori stool antigen test. Parents answered a questionnaire with demographic data at baseline. The test was performed according to previously standardized procedures, and results lesser than 0.140 were regarded as negative; higher than 0.016 were regarded as positive.
  
  
  RESULTS
  Age ranged from 0.7 to 7.48 years (3.67+/-1.98 y) at baseline, with 58% female and 42% male. H. pylori prevalence was 12.5% (14/112). There was a trend to associate low income (P=0.06), ethnicity non-white (P=0.075), and smaller house (P=0.079) to H. pylori infection at baseline in univariate analysis. Nevertheless, age was the only variable associated to prevalence at multivariate analysis. There was no significant association between H. pylori infection and intestinal parasites. There was only one new infection during the study period (incidence rate 0.53%), and 4 children cleared the infection (elimination rate 2.15%). All those children were older than 4 years.
  
  
  CONCLUSIONS
  Spontaneous eradication of the infection was more frequent than incidence of infection in this cohort.
authors.affiliation: Pediatric Gastroenterology, Department of Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil.
authors.forename: Aurea Cristina Portorreal
authors.initials: AC
authors.lastname: Miranda
authors.forename: Rodrigo Strehl
authors.initials: RS
authors.lastname: Machado
authors.forename: Elisabete
authors.initials: E
authors.lastname: Kawakami
mesh_terms: D000942:Antigens, Bacterial / Q000302:isolation & purification*; D002648:Child; D002656:Child Day Care Centers; D002675:Child, Preschool; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000382:microbiology*; D005260:Female; D016481:Helicobacter Infections / Q000382:microbiology / Q000503:physiopathology*; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D007223:Infant; D008297:Male; D012075:Remission, Spontaneous; D013997:Time Factors
chemical_list: D000942:Antigens, Bacterial