Objective: To explore the difference in infection of Helicobacter pylori (Hp) and their subtypes cagA+ and hspA+ in the residents living in the areas with high and low incidence of gastric cancer.
Methods: Immunoglobulin G and A antibodies against Hp and immunoglobulin G antibodies against cagA+ and hspA+ were detected for the residents in Linqu and Cangshan Counties of Shandong Province with enzyme-linked immunosorbent assay (ELISA).
Results: Rate of infection with Hp in the residents in Linqu County, an area with high incidence of gastric cancer, was 73.8 percent, significantly higher than that in Cangshan County (59.9%), an area with low incidence. Rates of infection with Hp cagA+ and hspA+ in the residents in Linqu County were 50.9 and 17.0 percent, respectively, also significantly higher than those in Cangshan County (34.0% and 13.2%, respectively). Sensitivities and specificities of the methods for detecting antibodies against Hp, cagA+ and hspA+ were 92.3, 63.2 and 21.9 percent and 71.0, 80.6 and 95.2 percent, respectively, evaluated with 13C-urea breath teat (13C-UBT). Rate of infection with Hp, especially with Hp cagA+, correlated significantly with the high incidence of gastric cancer.
Conclusion: The methods for detecting antibodies against Hp and cagA+ subtype are more sensitive and can be used as better indicators in epidemiological studies on gastric cancer.