A series of 143 subjects representing an Estonian urban population was examined for the occurrence and extent (absent, mild, moderate, severe) of Helicobacter pylori colonization in antral and body biopsy specimens (Giemsa staining). These data were correlated with the presence and grade of chronic gastritis (normal, mild, moderate, or severe superficial chronic gastritis; mild, moderate, or severe atrophic gastritis) in the antrum and the body. Gastritis of any grade was found in the antrum and/or the body in 140 (98%) subjects. The overall extent of H. pylori colonization in the whole series did not differ between the antrum and the body. Of 93 subjects with superficial gastritis, H. pylori was found in the antrum and/or the body in 87 (94%) cases. Of 47 subjects with atrophic gastritis in the antrum and/or the body. H. pylori was not found in 12 (25%). In subjects with gastritis the absence of H. pylori either in the antrum or in the body was relatively common (in 30 of 143 subjects). The grade of superficial gastritis showed a highly significantly positive correlation with the extent of H. pylori colonization in the antrum but not in the body. Correspondingly, the grade of atrophic gastritis in the antrum correlated negatively to the grade of colonization. The total absence of H. pylori was particularly associated with the absence of gastritis in the antrum. Conversely, severe body H. pylori colonization was found in subjects who had atrophic antral gastritis, and severe antral colonization in subjects who had at least moderate superficial antral gastritis and who showed a coexistent normal or slight superficial gastritis in the body.(ABSTRACT TRUNCATED AT 250 WORDS)