title: Diagnosis of the infection by the Helicobacter pylori through stool examination: method standardization in adults.
abstract: OBJECTIVE
  Infection caused by Helicobacter pylori (H. pylori) is one of the most common causes of chronic infection in the world. The presence of the infection is strongly associated with the neoplasia of the gastrointestinal tract, and its diagnosis is easily made by means of invasive or non-invasive methods. Among such methods, the H. pylori antigen detection in stool through ELISA technique is easily performed and it is an alternative to endoscopy in children, since this exam is not usually indicated in this age group. The aim of the current study is to establish the standardization of the ELISA method for the detection of H. pylori in stool specimens in Brazil.
  
  
  METHODS
  Patients between 18 and 70 years of age were randomly selected in the gastroenterology ambulatory center at Faculdade de Medicina do ABC between 2007 and 2009. They all answered a questionnaire to investigate possible dyspeptic symptoms and then underwent endoscopy and detection of H. pylori through no more than 4 methods. Besides the gastric biopsy, established as the gold standard test, the urease test, the stool ELISA test and serology were also methods applied.
  
  
  RESULTS
  The sensitivity and specificity of the exams in this sample were respectively 87.2% and 44% for the stool ELISA test, 41.9% and 64% for serology, 65.6% and 58.8% for the urease test and 100% and 80.8% for the clinical analysis.
  
  
  CONCLUSIONS
  The ROC curve showed a good correlation between the compared methods. In Brazil the standardization of the ELISA test for the detection of H. pylori in stool specimens constitutes a non-invasive diagnostic alternative.
authors.affiliation: Department of Gastroenterology, Faculdade de Medicina do ABC, Santo André, Brazil. Electronic address: chehter.ops@terra.com.br.
authors.forename: E Z
authors.initials: EZ
authors.lastname: Chehter
authors.forename: M R
authors.initials: MR
authors.lastname: Bacci
authors.forename: F L A
authors.initials: FL
authors.lastname: Fonseca
authors.forename: J A C
authors.initials: JA
authors.lastname: Gonçalves
authors.forename: G
authors.initials: G
authors.lastname: Buchalla
authors.forename: S A R
authors.initials: SA
authors.lastname: Shiraichi
authors.forename: R C
authors.initials: RC
authors.lastname: Mariano
mesh_terms: D000293:Adolescent; D000328:Adult; D000942:Antigens, Bacterial / Q000097:blood; D001426:Bacterial Proteins / Q000032:analysis; D001706:Biopsy; D001938:Brazil; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000592:standards*; D005243:Feces / Q000382:microbiology*; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000382:microbiology; D016480:Helicobacter pylori / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D014510:Urease / Q000032:analysis
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D014510:Urease
keywords: Dyspepsia; H. pylori; Stool ELISA test; Urease test