Drug susceptibility pattern of Helicobacter pylori in patients with dyspepsia at the Kenyatta National Hospital, Nairobi

Abstract

Objective: To determine drug susceptibility pattern of Helicobacter pylori to metronidazole, clarithromycin, amoxicillin and tetracycline in patients presenting with dyspepsia at the Kenyatta National Hospital.

Design: Cross-sectional descriptive study.

Setting: Kenyatta National Hospital, Nairobi.

Subjects: Two hundred and sixty-seven patients aged 15 to 85 years, presenting with dyspepsia and referred for upper gastro-intestinal endoscopy were recruited into the study.

Results: Between October 2003 and April 2004, 138 male and 129 female patients aged 15-85 years, with a mean age of 45.4 years were studied. Gastritis was the most common endoscopic finding, occurring in 55%, followed by normal-looking mucosa in 27% and peptic ulcer disease in 16% of the patients. The rapid urease test was positive in 184 patients (69%). The culture yield was 62% of these CLO (Campylobacter like organisms) positive biopsies. The MIC90 (minimum inhibitory concentration) was 256 mg/l for metronidazole, 1.5 mg/l for clarithromycin, 1.5 mg/l for tetracycline and 0.75 mg/l for amoxicillin. The MIC values for amoxicillin were significantly higher in the female patients (p = 0.02) but showed no significant variation for age. The MIC values for metronidazole, tetracycline and clarithromycin showed no significant difference for age or gender. MIC values for tetracycline were significantly higher for patients with duodenitis and duodenal ulcer p = 0.009 and 0.02, respectively.

Conclusion: All isolated H. pylori organisms were resistant to metronidazole. The susceptibility of the H. pylori isolates was 93.6% for clarithromycin, 95.4% for amoxicillin and 98.1% for tetracycline. The MIC90 for amoxicillin and clarithromycin were found to be close to the upper limit of the susceptibility range. There was a rising MIC90 for tetracycline and metronidazole compared to that found in a previous study in 1991.