Seroepidemiological study of the immune response to Campylobacter pylori in potential risk groups.

To gain more understanding of the epidemiology of Campylobacter pylori infection, the immune response to the organism was studied in the following selected potential risk groups: endoscopy staff (n = 45), dental staff (n = 58), orphanage children (n = 24), psychiatric patients (n = 58), and family contacts of Campylobacter pylori-infected patients (n = 55). The frequency of an IgG and IgA antibody response in the different groups was determined by the immunoblot method and compared with that in an appropriate control group (n = 189). The frequency of a positive antibody response was dependent on age (p less than 0.0001) but not on sex. When results were corrected for age by logistic regression analysis, all groups, with the exception of dental staff and orphanage children, revealed a significantly raised frequency of an IgA and combined IgG/IgA immune response compared to controls. There was not a significant difference for the IgG response, except in orphanage children. It is concluded that endoscopy staff, family contacts of Campylobacter pylori-infected patients and people living in closed communities such as psychiatric patients and orphanage children must be considered as risk groups for Campylobacter pylori infection. The findings support the notion that person-to-person spread and a common source are the predominant modes of transmission of Campylobacter pylori in addition to endoscopes.