<P> Noninvasive tests for H. pylori infection may be suitable and include blood antibody tests, stool antigen test s, or the carbon urea breath test (in which the patient drinks C--or C - labelled urea, which the bacterium metabolizes, producing labelled carbon dioxide that can be detected in the breath). It is not known which non-invasive test is more accurate for diagnosing a H. pylori infection, and the clinical significance of the levels obtained with these tests are not clear . Some drugs can affect H. pylori urease activity and give false negatives with the urea - based tests . </P> <P> An endoscopic biopsy is an invasive means to test for H. pylori infection . Low - level infections can be missed by biopsy, so multiple samples are recommended . The most accurate method for detecting H. pylori infection is with a histological examination from two sites after endoscopic biopsy, combined with either a rapid urease test or microbial culture . </P> <P> H. pylori is a major cause of certain diseases of the upper gastrointestinal tract . Rising antibiotic resistance increases the need to search for new therapeutic strategies; this might include prevention in the form of vaccination . Much work has been done on developing viable vaccines aimed at providing an alternative strategy to control H. pylori infection and related diseases, including stomach cancer . Researchers are studying different adjuvants, antigens, and routes of immunization to ascertain the most appropriate system of immune protection; however, most of the research only recently moved from animal to human trials . An economic evaluation of the use of a potential H. pylori vaccine in babies found its introduction could, at least in the Netherlands, prove cost - effective for the prevention of peptic ulcer and stomach cancer . A similar approach has also been studied for the United States . </P> <P> The presence of bacteria in the stomach may be beneficial, reducing the prevalence of asthma, rhinitis, dermatitis, inflammatory bowel disease, gastroesophageal reflux disease, and esophageal cancer by influencing systemic immune responses . </P>

H. pylori is the bacterium responsible for causing gerd