Helicobacter pylori colonization in early life

Helicobacter pylori infection is a major cause of upper gastrointestinal di sease throughout the world. Colonization begins in childhood, although litt le is known about its age of onset, rate, or mode of colonization. Our aim was to identify the age of acquisition of H. pylori colonization in Gambian children. A cohort of 248 Gambian children aged 3 to 45 months was studied at intervals of 3 months for 2 years, using the C-13-urea breath test, spe cific IgM and specific IgG serology. The prevalence of positive breath test s rose from 19% at 3 months of age to 84% by age 30 months. Elevated specif ic IgG and IgM antibody levels were associated with positive breath tests, although there was discrepancy between breath test results and serology, pa rticularly IgG serology, during the Ist year of life. Neither IgG nor IgM s erology could be validated as reliable diagnostic tools for infant H. pylor i colonization compared with the C-13-urea breath test. Reversion to negati ve breath test, in association with declining specific antibody levels, occ urred in 48/248 (20%) of children. On the assumption that the C-13-urea bre ath test is a reliable index of H. pylori colonization, we conclude that th e infection is extremely common from an early age in Gambian children. Tran sient colonization may occur. Previous studies relying on serodiagnosis may have significantly underestimated the true early prevalence of colonizatio n in the developing world, where the target age for intervention studies is probably early infancy.