Helicobacter pylori and Helicobacter heilmannii in untreated Bulgarian children over a period of 10 years.

The aims of the study were to evaluate the incidence of Helicobacter pylori and Helicobacter heilmannii in untreated Bulgarian children from 1996 to 2006, to analyse the performance of diagnostic tests, and to look at H. pylori density in specimens by culture. Antral specimens from children with chronic gastritis (n=513), peptic ulcers (n=54) and other diseases (n=91) were evaluated by direct Gram staining (DGS), in-house rapid urease test (RUT) and culture. The living environment and semi-quantitative H. pylori density were assessed in 188 and 328 children, respectively. H. pylori infection was found in children with ulcers (77.8 %), chronic gastritis (64.5 %) and other diseases (36.3 %). Half (51.4 %) of patients aged 1-5 years and 77.4 % of those aged 16-17 years were H. pylori-positive. Of all children, 328 (49.8 %) showed positive DGS, 184 (28 %) had a positive RUT, and 386 (58.7 %) were culture-positive. Unlike gastric mucus specimens, frozen biopsy specimens provided reliable diagnosis. H. heilmannii was observed in two (0.3 %) children. High H. pylori density (growth into all quadrants of plates) was found in 18 % of 328 children evaluated, involving 31 % of ulcer and 16.7 % of non-ulcer patients. H. pylori infection was more common in rural children with chronic gastritis (91.3 %) than in the remainder (66.7 %). In conclusion, H. pylori infection was common in symptomatic Bulgarian children. The infection prevalence was >77 % in patients aged 16-17 years, in children with a duodenal ulcer, and in rural patients. H. heilmannii infection was uncommon. The performance of the bacterial culture was good. The impact of H. pylori density on the clinical expression and eradication of the infection requires further evaluation. The results highlight the need for routine H. pylori diagnosis in rural children with chronic gastritis.