title: Helicobacter pylori recurrence in developed and developing countries: meta-analysis of 13C-urea breath test follow-up after eradication.
abstract: OBJECTIVE
  Recurrence of Helicobacter pylori infection after eradication is rare in developed countries and more frequent in developing countries. Most recurrent cases are attributed to recrudescence (recolonization of the same strain within 12 months) rather than to reinfection (colonization with a new strain after more than 12 months). The aim of the study was to analyze recurrence rates in developed and developing countries and to deduce the relative roles of recrudescence and reinfection.
  
  
  METHODS
  The PubMed database was searched up to January 31, 2007 using the keywords "Helicobacter pylori" or "H. pylori" and "recurrence" or "recrudescence," or "reinfection." Only prospective case studies in adults that used the (13)C-urea breath test ((13)CUBT) were included. Meta-analyses were performed with statdirect Statistical software, version 2.6.1, StatsDirect Ltd, Chesire, UK.
  
  
  RESULTS
  The literature search yielded 10 studies of H. pylori recurrence in developed countries (3014 patients followed for 24-60 months) and 7 studies in developing countries (2071 patients followed for 12-60 months). The calculated annual recurrence rates were 2.67% and 13.00%, respectively. Nested meta-analysis of cases with a longer follow-up after eradication revealed an annual recurrence rate of 1.45% (RR 0.54) in developed countries and 12.00% (RR 0.92) in developing countries.
  
  
  CONCLUSIONS
  The similarity of the annual recurrence rates during the first year after eradication and the annual recurrence rates in the second year after successful eradication in developing countries supports reinfection as the main cause in the second period. Therefore, a different approach for follow-up of H. pylori eradication may be needed between developed and developing countries.
authors.affiliation: Department of Gastroenterology, Rabin Medical Center, Beilinson Hospital, Petach Tikva and Sackler Faculty of Medicine, Tel Aviv University, Israel. yniv@clalit.org.il
authors.forename: Yaron
authors.initials: Y
authors.lastname: Niv
authors.forename: Rachel
authors.initials: R
authors.lastname: Hazazi
mesh_terms: D000328:Adult; D001944:Breath Tests / Q000379:methods*; D019049:Developed Countries; D003906:Developing Countries; D005500:Follow-Up Studies; D016481:Helicobacter Infections / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D011446:Prospective Studies; D012008:Recurrence; D014508:Urea / Q000032:analysis*
chemical_list: D014508:Urea