Helicobacter pylori infection in Africa: Pathology and microbiological diagnosis

Abstract

Helicobacter pylori is a microaerophilic motile curve rod that inhabits the gastric mucosa of the human stomach. The organism chronically infects billions of people worldwide and is one of the most genetically diverse of bacterial species. Infection with the bacterium which leads to chronic gastritis, peptic ulceration, gastric cancers and gastric MALT lymphoma has been reported to follow a pattern linked to geographic and socio-demographic factors. However; the infection rate in various populations does not parallel the incidence of morbidity caused by the infection. This has been termed by a number of authors as the ‘African enigma’ based on an apparently low incidence of gastric carcinoma and other H. pylori-associated morbidities in the continent of Africa. There are various techniques employed to detect H. pylori from specimens. These tests may be invasive or non-invasive. Endoscopy and gastric
mucosal biopsy, microscopic examination of histological sections, PCR and rapid urease test are forms of invasive test that could be used. Non-invasive tests such as Urea Breath Test (UBT) make use of the
ability of the organism to produce urease; enzyme linked immunosorbent Assay (ELISA), H. pylori stool antigen test, and latex agglutination tests are important non-invasive serological approaches employed to detect the presence of antibody or antigen from a specimen. H. pylori is a very fastidious bacterium. Restraint should therefore be exercised to allow for efficient performance of some of these techniques.