Factors associated with Helicobacter pylori infection by a cagA-positive strain in children

Although infection with a cagA-positive Helicobacter pylori strain is consi dered a risk factor for the development of duodenal peptic ulcer in adults, this association has not been demonstrated in children. The presence of ca gA was investigated by polymerase chain reaction in H. pylori strains isola ted from 27 children with duodenal ulcer and 53 without duodenal ulcer. All patients (100%) with duodenal ulcer and 33 (62.3%) without ulcer were colo nized by a cagA-positive strain (P = .00007), A cagA-positive status was al so associated with a more marked macroscopic gastritis, with a greater infl ammatory infiltrate of both mononuclear and polymorphonuclear cells in the antral and oxyntic gastric mucosae and degenerative and regenerative change s of the gastric mucosa. Increased cagA positivity was also associated with increased age, but no association between cagA-positive status and sex was observed.