I was treated a little more than a year ago for H. pylori. What is the percentage of persons who again contract H. pylori?

M.

Helicobacter pylori (H. pylori) is a type of bacterium that is often found in the stomach. Although it was first identified less than 20 years ago, there has been much research into its ability to cause disease. We know that the vast majority of infected people experience no symptoms. However, in some, H. pylori can cause gastritis, a painful inflammation of the stomach. In other patients, H. pylori can lead to ulcers of the stomach and/or upper intestine (duodenum). In fact, H. pylori is one of the two most common causes of ulcers, the other being the use of nonsteroidal anti-inflammatory drugs (NSAIDs). H. pylori is also associated with an increased risk for stomach cancer and lymphoma -- again in a very small percentage of patients.

One of the great breakthroughs in ulcer therapy came when it was determined that patients who have ulcers and are infected with H. pylori have a very low rate of ulcer recurrence rate if the infection is treated with antibiotics. Before this discovery, up to 75 percent of ulcer patients wouldTreatment of H. pylorithat is causing symptoms involves a combination of drugs -- normally two antibiotics and one acid-suppressing drug. A common combination is clarithromycin (Biaxin), amoxicillin and omeprazole (Prilosec), each given twice a day for 10-14 days. Several other accepted combinations are also available, and different antibiotics can be used in patients allergic to penicillin. When the medications are taken as prescribed, the chance of cure is more than 90 percent. However, a small group of patients will need to be treated again with a different combination of drugs because some strains of H. pylori have developed resistance to some of the drugs.

Once an H. pylori infection is cured, reinfection is not common, probably occurring less than 5 percent of the time. There has not been a great deal of research done in this area. The few studies that have been done show that reinfection tends to occur from close contacts, such as family members. In underdeveloped countries, where the prevalence of H. pylori is very high even among children, the reinfection rate after cure is substantially higher (20-30 percent). Doctors think this stems from the fact that this organism is so ubiquitous in those environments.