Division of Infectious Diseases, Department of Medicine, New York University School of Medicine, New York, NY 10010, USA. guillermo.perez-perez@med.nyu.edu
The prevalence of Helicobacter pylori colonisation in populations in developed country has been declining, as shown by community based serological surveys of adults in Vammala, Finland in 1973 and 1994. In this study, we determined whether the proportion of subjects colonised by cagA(+) or cagA(-) H pylori strains has changed as the overall prevalence of H pylori(+) has declined.
We examined 911 sera from Vammala's study for antibodies to the CagA antigen of H pylori using a truncated CagA protein as the antigen in an ELISA and we examined the trend in acquisition and carriage of cagA(+) strains.
As expected, the prevalence of carriage of both cagA(+) and cagA(-) strains fell between 1973 and 1994 (p