Regions with high gastric cancer incidence rate tend to have
high seroprevalence rates for H. pylori infection. However,
there are geographical regions, such as Africa and South Asia
(e.g. India), where the seroprevalence rates for H. pylori infection
are high but the gastric cancer incidence rates are low. This
phenomenon has been dubbed the Asian or African enigma,(3,31)
and is probably a reflection of the complex host, bacterial and
environmental factors at play in gastric carcinogenesis. It has
also been suggested that disease manifestation reflects the
predominant pattern of gastritis within a geographical region, and
that the main factor is the interaction of host and environmental
factors such as diet, and not the bacterial strain.(3)