Helicobacter pylori is chiefly acquired in childhood. However, but the exact timing of this acquisition is not clearly understood.
In this study, researchers from the United States assessed H. pylori acquisition in a pediatric population.
The research team studied 2 cohorts of Native American children. The first was a birth cohort of 50 children, and the second was a cohort of 58 older children, who had a mean age of 53 months.
The team measured serum immunoglobulin G (IgG), IgM, and IgA antibodies to H. pylori whole-cell antigen and IgG antibodies to CagA.
|69% of the older children had H. pylori antibodies at study entry.|
|Journal of Clinical Microbiology|
They found that of the 44 children in the birth cohort who were monitored for more than 12 months, 55% had seroconversions, 16% were transient, and 39% were persistent.
However, among the older cohort, 85% of the children were monitored for 1 year, and 69% of these had H. pylori antibodies at study entry. The team found that during the following year, 21% seroreverted, while 33% of the 15 initially negative children seroconverted.
They found that in both cohorts, evaluation of CagA antibodies increased the sensitivity of H. pylori detection.
The team determined that serum pepsinogen I (PGI) levels in the H. pylori-negative children rose significantly until age 6 months. These then remained constant for the next 19 months.
They also found that at the time of H. pylori seroconversion, PGI peaked to levels significantly higher than in the never-seroconverted, and the pre-seroconverted. However, levels then declined to those of H. pylori-negative children.
Dr Guillermo Pérez-Pérez's team concluded, "H. pylori acquisition, accompanied by a transient PGI increase, was frequent in this population, especially in the second and third years of life, but often was brief".