COPENHAGEN — The local prevalence of Helicobacter pylori and antibiotic-resistant H. pylori help determine who to test for gastric infection and how to treat them, according to the revised Maastricht guidelines.

The third edition of the influential Consensus Report of the European H. pylori Study Group was drafted last March by a panel of European experts; the new guidelines are called Maastricht 3.

The recommendations were detailed in a special session at the 13th United European Gastroenterology Week. At press time a publication date had not been set.

The guidelines cover three issues: who to test and treat for H. pylori, how to test and treat, and how to prevent gastric cancer triggered by H. pylori.

Who to Test and Treat

Patients who should be tested for H. pylori include those starting long-term NSAIDs, patients with unexplained iron-deficiency anemia, and patients with immune thrombocytopenia.

Other indications include peptic ulcer disease, nonulcer dyspepsia, mucosa-associated lymphoid tissue (MALT) lymphoma, atrophic gastritis, a history of gastric cancer resection, first-degree relatives of patients with gastric cancer, and patients who, on consulting with a physician, want to be tested.

Test-and-treat is endorsed as a management strategy for dyspepsia because study results have shown that it is as effective as routine endoscopy while reducing use of endoscopy and of antisecretory medication, said Colm O'Morain, M.D., professor of medicine at Trinity College, Dublin, and a cochair of Maastricht 3.

In regions where infection rates by H. pylori are high (prevalence above 20%), test-and-treat is the preferred option, he added. In regions where the prevalence of infection is less than 20%, empiric treatment with antisecretory medication first is just as effective and may be more appropriate.

The guidelines also highlight the fact that eradication of H. pylori does not cause gastroesophageal reflux disease, but curing an infection and resolving an ulcer may unmask reflux that was not previously diagnosed.

Eradication of H. pylori can also halt the extension of and may even cause regression of atrophic gastritis. But eradication will not affect the efficacy of proton pump inhibitors.

The guidelines say that H. pylori and NSAIDs are independent and synergistic causes of peptic ulcers. Eradicating H. pylori alone cannot prevent or stop bleeding caused by chronic NSAID use, but a patient starting a long-term course of an NSAID or aspirin should be tested for H. pylori and treated if positive, Dr. O'Morain said.

How to Test and Treat

Mainstays of testing are the urea breath test and stool antigen test, although serology tests also have a role, said Francis Mégraud, M.D., a professor of bacteriology at Pellegrin Hospital in Bordeaux, France, another conference cochair.

Both tests work best in patients not being treated with an antisecretory drug, and in those who do not have a bleeding ulcer, atrophic gastritis, or a MALT lymphoma. In patients who are taking an antisecretory drug or have one of these conditions, a serology test is best. But serology can be inferior because individual tests require validation, and it can be hard to distinguish between new and old infections.

In general, first-line treatment for H. pylori eradication is a proton pump inhibitor, 500-mg clarithromycin b.i.d., and either amoxicillin or metronidazole. A 14-day regimen is more effective, but 7 days can be appropriate and cost effective when local studies prove that it's effective. A quadruple-drug regimen that also includes bismuth is an alternative first-line option. Resistance to clarithromycin is a growing problem. In some regions of southern Europe, 20% of isolates are resistant. There is a small advantage to using metronidazole instead of amoxicillin, but either is acceptable. Metronidazole is preferred in regions where the prevalence of metronidazole resistance is less than 40%.

The top second-line regimen is quadruple therapy that adds bismuth to the first-line trio of drugs. Another second-line option is a proton pump inhibitor plus metronidazole and amoxicillin. Although a quinolone, such as levofloxacin, can effectively eradicate many H. pylori infections, a quinolone is not a good first- or second-line choice because its use would lead to drug resistance, Dr. Mégraud said.

Patients should be retested to confirm eradication 4 weeks after starting treatment. A urea breath test is the top follow-up test, followed by stool antigen testing. If a patient remains infected despite treatment, the next antibiotic choice should be determined by susceptibility testing.

Preventing Gastric Cancer

Study results show that about 70% of noncardia adenocarcinoma is attributable to infection by H. pylori, said Peter Malfertheiner, M.D., director of the department of gastroenterology at Otto von Guericke University in Magdeburg, Germany, and the third cochair of Maastricht 3.

Eradication of H. pylori prevents alterations in gastric chemistry and preneoplastic changes in the gastric mucosa. “In theory, H. pylori eradication should reduce the risk of gastric cancer,” he said. “The optimal time to start treatment is before preneoplastic lesions appear, but it's never too late to eradicate,” Dr. Malfertheiner said.

Updated Maastricht Guidelines Address H. pylori Testing, Therapy