SEROEPIZOOTIOLOGY OF HELICOBACTER-PYLORI GASTRIC INFECTION IN NONHUMAN-PRIMATES HOUSED IN SOCIAL ENVIRONMENTS

We determined the seroepizootiology of Helicobacter pylori infection in rhesus monkeys. Plasma was obtained from 196 animals (age range, 1 to 22 years) that were housed in social environments, either in indoor gang cages, in outdoor corrals, or in free-ranging forested conditions. Plasma immunoglobulin G levels were determined with a specific enzyme-linked immunosorbent assay, and the cutoff immunoglobulin G value for H. pylori seropositivity was determined from a study of 25 monkeys whose infection status was assessed by light microscopy and culture. One-year-old animals of both genders in all housing conditions had the lowest rate of positivity (60% in monkeys 1 year old versus 81% in monkeys 2 to 10 years old, P = 0.026). In addition, females tended to have higher rates of positivity than males. Seroconversion during a 1-year observation period occurred in 7 (28%) of 25 seronegative animals, Seroreversion occurred in 3 (4%) of the 78 positive animals; all 3 of these animals had received antimicrobial agents during the year, These observations demonstrate that the epizootiology of H. pylori infection in rhesus monkeys may serve as a model for human infection.