Seroepidemiology of Campylobacter pylori infection in various populations.

Campylobacter pylori infection has been recognized as being strongly associated with chronic gastritis and duodenal ulceration, but the prevalence of C. pylori infection in a normal population is not known. A serological survey was conducted in four countries with different geographical and socioeconomic status, in a randomly chosen population as representative as possible, by using an enzyme-linked immunosorbent assay (ELISA) with a sonic extract of two strains as the antigen. The test had a specificity of 94% when 600 ELISA units was used as the threshold. In France, few children were infected before the age of 10 years. The prevalence then increased gradually to 36.7% in the sixth decade of life. This increasing prevalence of infection with age was also observed in Algeria, Vietnam, and the Ivory Coast but at a higher rate (80 to 90%). In Vietnam, as in France, few children were infected, whereas in Africa, C. pylori infection occurred earlier. The prevalence of infection did not differ with sex for a particular age group; it also did not differ with respect to gastric symptoms, smoking and drinking habits, or urban or rural residence when these potential risk factors were studied. The epidemiological data available on peptic ulcer disease in developing countries compared with developed countries led to the speculation that infection with C. pylori is not a sufficient condition to develop this disease.