Helicobacter pylori infections and gastric cancer: The West African experience

Abstract

The prevalence of Helicobacter Pylori (Hp) in West Africa is high and infection occurs early in childhood but there are very few studies on association of Hp with GC. Despite the high  prevalence of Hp, gastric cancer incidence is low and precancerous lesions are rare. Although most strains of Hp are positive for the virulent factor cagA gene as well as vacA s1, m1 or s1, m2; there is no consistent association with GC. Some studies have attributed the low incidence of GC to low prevalence of strains with multiple EPIYA-C segments of CagA gene and mixed infection by cagA positive and cagA negative strains which may be protective. Studies have also suggested that diets rich in anti-oxidants such as fresh fruits and vegetables decrease risk of GC while high salt diet increases the higher expression of CagA. More studies are therefore required to explain the dissociation between prevalence of Hp infection and gastric cancer in WA.