Symptoms
Infection with is an important factor in the development of gastritis, gastric and intestinal ulcers, gastric carcinoma, and MALT lymphoma. In contrast, no clinical symptoms are observed in the majority of patients. The acute stage of infection may manifest as gastrointestinal symptoms such as nausea, vomiting, and pain in the upper abdomen.
Causes
The cause of the symptoms is infection of the stomach with the gram-negative bacterium , which is usually transmitted orally-orally or fecally-in the first two years of life. Nearly half of all people on earth carry the bacterium. The prevalence is 10-60% in Western countries and can reach 100% in developing countries. With the help of the enzyme urease, urea can convert into the basic ammonia and thus survive in the acidic environment of the stomach. The infection leads to mucosal inflammation and damage in the stomach. The bacterium is resistant and remains in the stomach for the rest of its life unless removed with antibiotics.
Diagnosis
A diagnostic test is usually performed only when clinical symptoms are present. Various nonendoscopic and endoscopic methods are available for diagnosis:
- Serology (blood test, IgG).
- 13C-urea breath test (urease)
- Stool test (stool antigen)
- Endoscopy with biopsy: histology, urease activity, culture.
In the urea breath test, the patient ingests labeled 13C-urea. This is converted by the urease of the bacterium to carbon dioxide, which is absorbed into the bloodstream and detected in exhaled air.
Drug treatment
Drug treatment usually involves combination therapy with two antibiotics and a proton pump inhibitor, known as triple therapy. The duration of therapy differs between different countries and ranges from 7, 10 to a maximum of 14 days. “French” triple therapy in adults:
- Proton pump inhibitor, e.g. pantoprazole, 2 x daily 40 mg or omeprazole, 2 x daily 20 mg.
- Clarithromycin, 2 x daily 500 mg.
- Amoxicillin, 2 x daily 1000 mg
Treatment is challenging for patients in terms of both adherence and side effects. Furthermore, drug-drug interactions are to be expected because the macrolide clarithromycin is a potent CYP3A inhibitor. Potential adverse effects include headache, diarrhea, candida infections, rashes, and hypersensitivity reactions. The additional administration of a probiotic is recommended to prevent antibiotic-associated diarrhea and to positively influence treatment. Metronidazole can be used in place of amoxicillin for penicillin allergy at a dosage of 500 mg 2 times daily. Alternatively, bismuth salts, e.g., basic bismuth salicylate, tetracyclines, quinolones (levofloxacin), and rifabutin are also used. A problem with traditional triple therapy is the declining success rates due to increasing resistance, especially to clarithromycin and metronidazole. Therefore, after treatment, successful eradication should be confirmed with a diagnostic test. In case of treatment failure, another therapy regimen can be tried, for example, quadruple therapy with a bismuth salt. It is also possible to test the sensitivity of the bacteria to the antibiotics beforehand. See also under bismuth tetracycline metronidazole (+ omeprazole).
