Natural acquisition of Helicobacter pylori infection in newborn rhesus macaques

Abstract

Helicobacter pylori infection is usually acquired in childhood, but precise estimates of the age of acquisition are difficult to obtain in young children. Since serial endoscopic biopsies are not feasible in human infants, we examined acquisition of H. pylori infection that is known to occur in socially housed nonhuman primates. By 12 weeks of age, 8 of 20 newborns (40%) were culture positive for H. pylori, and prevalence reached 90% by 1 year of age. Newborns from infected dams were more commonly infected than those from uninfected dams, particularly during the peripartum period, suggesting that close contact during this time may facilitate transmission. Transient infection was uncommon and occurred only after the first positive culture. These results suggest that in a high-prevalence environment, persistent H. pylori infection may be acquired at an earlier age than was previously thought. Since clean, potable water was readily available, contamination of water supply is not essential for widespread infection at an early age in areas where hygiene is otherwise poor. Furthermore, breastfeeding seems to offer little protection, since newborn macaques breastfeed during the first year of life and typically are fully weaned only when another newborn arrives the following spring.

FIG. 1.

Cumulative percentage of babies positive for H. pylori by culture (filled circles) and serology (open circles) as a function of age (weeks).

FIG. 2.

Cumulative percentage of babies from infected (open squares) or uninfected (open circles) dams that were culture positive for H. pylori as a function of age.

FIG. 3.

Mean (SD) H. pylori CFU in the gastric antrum and corpus of newborn babies and their dams.

FIG. 4.

Rep-PCR products electrophoresed in a 1.5% agarose gel stained with ethidium bromide. Representative fingerprints from each of the five strains (A through E) are shown. A DNA kilobase (kb) ladder is at left.

FIG. 5.

Distribution of the five H. pylori strain types (A through E) among babies (solid bars) and their dams (shaded bars) from each of the five field cages. The field cage designation and the number of baby-dam pairs is shown in the upper right of each panel.