Cases of H. pylori stem from unknown

Dear Dr. Roach: Could you give some additional information about H. pylori infection? I was diagnosed with it recently. I was given instructions on antibiotics to be taken. When talking to my doctor’s physician assistant, I asked what could have caused the infection. I was given a very cursory response, including that it could have come from eating at “Mom and Pop” restaurants. From research, it seems that it can be present for a long period of time without being noticed.

After I finished the antibiotics, I was told to have a follow-up test to make sure they were effective. I was given a choice of a stool test or a breathing test; I chose the breathing test. Are those tests also used to initially detect an infection, without a biopsy? — A.J.Y.

Helicobacter pylori is an important cause of chronic gastritis, the most important cause of stomach ulcers, and is an important factor in stomach cancer and intestinal lymphoma. Between 50% and 66% of the population of the world is affected. It is thought that most infection occurs person-toperson, possibly through water or from poor handwashing before food preparation. H. pylori is much more common in developing nations.

Not everyone with H. pylori has symptoms or needs treatment. People with ulcers or gastritis are generally treated with several antibiotics. The diagnosis can be made by biopsy or by the stool or breath test.

The breath test is at least 95% specific (if the test is positive, it’s very likely to be a true positive) but 90% sensitive, meaning one person in 10 with the bacteria will have a false negative test. The stool test is close to 95% sensitive and specific. Blood testing is more likely to have false positive and false negative results. In addition, the stool or breath test is recommended to confirm eradication of the infection.