HP and chronic gastritis: Among the 34 participants who were Hp-positive at baseline and Hp-negative at follow-up, all 34 (100%) had chronic gastritis at baseline and 34 of 34 (100%) had lower chronic gastritis severity at follow-up; 33 (97%) had active gastritis at baseline and 33 of 33 (100%) had lower active gastritis severity at follow-up.