Moreover, in AfricanAmerican patients undergoing endoscopy: (1) HP infection was inversely related to the number of years the patients have been living in the USA; (2) HP infection rates were higher in patients diagnosed with duodenitis and peptic ulcer disease versus other disorders; (3) expression of the CagA gene was not associated with any specific gastroduodenal disorder; and (4) there was little allelic heterogeneity with respect to VacA and IceA subtypes.