title: Diagnosis of Helicobacter pylori infection in a high-prevalence pediatric population: a comparison of 2 fecal antigen testing methods and serology.
abstract: OBJECTIVE
  Accurate methods for diagnosing active Helicobacter pylori infection in children have been limited to invasive or time-consuming techniques. Recently, fecal antigen testing has been used successfully for the diagnosis of H pylori infection in the pediatric population. We compared 2 monoclonal fecal antigen diagnostic methods in a population of children with a suspected high prevalence of H pylori infection. We also assessed the diagnostic performance of H pylori immunoglobulin G serology.
  
  
  METHODS
  In a cross-sectional study of African refugee children (<16 years) we compared an immunochromatographic technique (ICT) and serology with a monoclonal fecal antigen enzyme immunoassay (MFAT) method for the detection of active H pylori infection. Following the manufacturer's instructions, an optical density of >or=0.190 was used as a cutoff for MFAT. Sensitivity, specificity, and positive and negative predictive values were calculated.
  
  
  RESULTS
  Of the 193 eligible children enrolled, active H pylori infection was detected in 149 of 182 (81.9%) in whom MFAT was performed. The prevalence of active infection increased with age; children with active infection were significantly older, and there were no sex differences. ICT and serology underperformed in comparison with MFAT (ICT sensitivity 74.6%, specificity 63.6%, positive predictive value 89.8%, negative predictive value 36.8%; and serology sensitivity 57.9%, specificity 77.4%, positive predictive value 92.0%, negative predictive value 29.9%).
  
  
  CONCLUSIONS
  Monoclonal enzyme immunoassay fecal antigen testing is a practical and feasible alternative to traditional invasive diagnostic methods in high-prevalence pediatric populations. Neither immunochromatography nor serology is useful for the diagnosis of active H pylori infection in these children.
authors.affiliation: School of Paediatrics and Child Health, University of Western Australia, Princess Margaret Hospital for Children, Perth, WA, Australia.
authors.forename: Sarah
authors.initials: S
authors.lastname: Cherian
authors.forename: David P
authors.initials: DP
authors.lastname: Burgner
authors.forename: Christine F
authors.initials: CF
authors.lastname: Carson
authors.forename: Frank M
authors.initials: FM
authors.lastname: Sanfilippo
authors.forename: Angus G
authors.initials: AG
authors.lastname: Cook
authors.forename: David A
authors.initials: DA
authors.lastname: Forbes
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000942:Antigens, Bacterial / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D005243:Feces / Q000382:microbiology*; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000453:epidemiology; D016480:Helicobacter pylori / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods / Q000592:standards; D007074:Immunoglobulin G / Q000097:blood*; D007223:Infant; D008297:Male; D011237:Predictive Value of Tests; D015995:Prevalence; D012036:Refugees; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods / Q000592:standards
chemical_list: D000942:Antigens, Bacterial; D007074:Immunoglobulin G