Helicobacter pyrlori in Malawi, central Africa.

A total of 160 adult Malawians with epigastric pain for longer than 2 weeks was investigated by endoscopy and serologically for evidence of infection with Helicobacter pylori. The organism was demonstrated histologically and/or by culture in 141 (88%) patients. With histological means and/or culture as the 'gold standard', the histological technique was 100% sensitive while culture was only 81% sensitive. All isolates tested were sensitive to amoxycillin and tetracycline; 74% were resistant to metronidazole. Endoscopic findings were normal in 104 (65%) patients (86.5% H. pylori positive). Evidence of duodenal ulcer was found in 41 (25%) patients (95% H. pylori positive). Histologically, gastritis was common, severe gastritis being associated with increased colonisation by H. pylori. Two kinds of urease test were found to be 100% specific for the presence of H. pylori. The sensitivity of the serological test (Helico-G test) was 98% but its specificity was only 27%. These results provide important background information for planned therapeutic studies in patients with upper gastro-intestinal disease in Malawi.