Prevalence, diversity and disease association ofHelicobacter pyloriin dyspeptic patients from Pakistan

Introduction: The etiological association of Helicobacter pylori with gastric ulcer (GU), gastric cancer (GC), and duodenal ulcer (DU) is well-known. Understanding the epidemiology ofH. pylorifacilitates the estimation of disease burden in a certain population. This study presents the diversity ofH. pylorigenotypes and their association with different clinical outcomes among dyspeptic patients in Pakistan over a period of four years.Methodology: Gastric biopsy samples from a total of 450 dyspeptic individualswere subjected to PCR, genotypingand histology.Results: A total of 201 (45%) cases were found positive forH. pylori. The detection rate was high in GU (91%), DU (86%) and GC (83%) cases compared with those cases who had intact gastric mucosa (18%). Histology revealed the presence of infection in 68% of cases of mild/chronic nonspecific gastritis with others belonging to the GU sequel. cagA gene carriage was observed in 104 (51%) cases or mostly from DU, GU and GC groups, of which 97 were Western type strains while 3 were East-Asian type strains that are rarely observed in South Asia. vacA allelic variant s1am1 was most commonly observed, followed by s1am2, and s1bm1, with direct correlation in diseased cases (gastritis, GU, DU and GC). Prevalent genotypic combinations were s1am1/cagA-in gastritis and s1am1/cagA+in DU, GU, and GC.Conclusions: Our study indicates the predominant circulation of Western typecagAandvacAs1am1 typeH. pyloristrains in Pakistan.