Helicobacter and disease: still more questions than answers.

Since the causative role of Helicobacter pylori in peptic ulcer and gastritis was established, a number of advances have been made. Helicobacter virulence factors have been identified, the changes it causes in gastric acid secretion has been elucidated, and the entire genome of H. pylori has been mapped. Multiple lines of evidence indicate a strong link between the bacterium and noncardia gastric cancer. The infection can be confidently diagnosed by noninvasive serologic tests and the urea breath test. Triple therapy is almost always curative, and the infection almost never recurs in Canadian adults, but eradicating the bacteria in the absence of peptic ulcer only rarely leads to resolution of dyspepsia. New studies suggest that treating Helicobacter may increase the risk of peptic esophagitis and adenocarcinoma of the esophagus and cardia.