... The cagA gene was present in 94-97% of subjects in all categories, but the cagA antibody was less prevalent in nonulcer dyspepsia (69%, 95% CI: 48-86%, p = 0.02) and GERD (69%, CI: 39-91%, p < 0.05) than in those with gastroduodenal pathology...
http://cancerweb.ncl.ac.uk/cancernet/cancerlit/704065.html