smoking, proton pump inhibitors and antibiotic administration as factors affecting direct screening of helicobacter pylori infection among patients with dyspepsia

background helicobacter pylori diagnostic tests can be affected by different interventional factors. we studied the effects of smoking, proton pump inhibitors (ppis) and antibiotic administration on results of the bacterial culture, and its diagnosis tests due to polymerase chain reaction (pcr) and rapid urease test (rut) methods. objectives this study was aimed to investigate the undesirable effects of ppi and antibiotics on the results of h. pylori screening tests in patients with gastritis. patients and methods a total of 100 patients with gastritis and indication for upper gastrointestinal (gi) endoscopy were enrolled in this study. three biopsy samples from each patient were immediately processed for detection of h. pylori based on culture, rut, and pcr methods. the sensitivity of these three detection methods was measured in the three infected patients groups that were subjected to conventional therapy, proton pump inhibitors (ppis) therapy, and no medication as control group. the possible effects of ppis and antibiotics on h. pylori detection were analyzed in vitro. results the prevalence of h. pylori infection was higher among the non users and ppi users (40% and 57.9%, respectively), while the number of isolated bacteria from the patients with a history of recent antibiotic prescription was significantly lower (18.75%) (p <0.05). an inverse association was found between h. pylori infection and smoking. among the studied methods, pcr showed the highest sensitivity in all groups. the results of rut illustrated a significant difference between the ppi users and patients with a history of recent antibiotic administration that was consistent with the results of in vitro study (p = 0.01). conclusions this study revealed a lower sensitivity of common h. pylori screening tests during the antibiotic or ppi administration. pcr was determined as the most accurate test used for diagnosis of h. pylori infections.