title: Diagnostic accuracy of tests for Helicobacter pylori in an Alaska Native population.
abstract: OBJECTIVE
  To evaluate the accuracy of two non-invasive tests in a population of Alaska Native persons. High rates of Helicobacter pylori (H. pylori) infection, H. pylori treatment failure, and gastric cancer in this population necessitate documentation of infection status at multiple time points over a patient's life.
  
  
  METHODS
  In 280 patients undergoing endoscopy, H. pylori was diagnosed by culture, histology, rapid urease test, (13)C urea breath test (UBT), and immunoglobulin G antibodies to H. pylori in serum. The performances of (13)C-UBT and antibody test were compared to a gold standard defined by a positive H. pylori test by culture or, in case of a negative culture result, by positive histology and a positive rapid urease test.
  
  
  RESULTS
  The sensitivity and specificity of the (13)C-UBT were 93% and 88%, respectively, relative to the gold standard. The antibody test had an equivalent sensitivity of 93% with a reduced specificity of 68%. The false positive results for the antibody test were associated with previous treatment for an H. pylori infection [relative risk (RR) = 2.8]. High levels of antibodies to H. pylori were associated with chronic gastritis and male gender, while high scores in the (13)C-UBT test were associated with older age and with the H. pylori bacteria load on histological examination (RR = 4.4).
  
  
  CONCLUSIONS
  The (13)C-UBT outperformed the antibody test for H. pylori and could be used when a non-invasive test is clinically necessary to document treatment outcome or when monitoring for reinfection.
authors.affiliation: Arctic Investigations Program, Division of Preparedness and Emerging Infections, National Center for Emerging Zoonoses and Infectious Diseases, Centers for Disease Control and Prevention, Anchorage, AK 99508, United States. dbruden@cdc.gov
authors.forename: Dana L
authors.initials: DL
authors.lastname: Bruden
authors.forename: Michael G
authors.initials: MG
authors.lastname: Bruce
authors.forename: Karen M
authors.initials: KM
authors.lastname: Miernyk
authors.forename: Julie
authors.initials: J
authors.lastname: Morris
authors.forename: Debby
authors.initials: D
authors.lastname: Hurlburt
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Hennessy
authors.forename: Helen
authors.initials: H
authors.lastname: Peters
authors.forename: Frank
authors.initials: F
authors.lastname: Sacco
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Parkinson
authors.forename: Brian J
authors.initials: BJ
authors.lastname: McMahon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000413:Alaska / Q000453:epidemiology; D000907:Antibodies, Bacterial / Q000097:blood; D001944:Breath Tests / Q000379:methods; D003955:Diagnostic Tests, Routine / Q000592:standards*; D016099:Endoscopy, Gastrointestinal; D005260:Female; D016481:Helicobacter Infections / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology; D016480:Helicobacter pylori / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D044382:Population Groups; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000175:diagnosis / Q000209:etiology; D014508:Urea / Q000378:metabolism; D014510:Urease / Q000378:metabolism; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D014508:Urea; D014510:Urease