HP and infection: Of course, there were also some limitations of this study: 1) the study population was limited to a single region and need to be validated in more regional populations; 2) the specificity of the RUT was susceptible to the interference of urease-positive bacteria, and more precise typing of Hp-infection required PCR verification; 3) the Hp-infection typing based on serum Hp antibody could not distinguish between current infection and previous infection.