[Studies on infection of Helicobacter pylori and their subtypes cagA+ and hspA+ in population living in the areas with high and low incidence of gastric cancer].

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.