Not to belabor second-year pathophysiology courses, but first, a couple of lines about what H. pylori actually is. It’s a flagellated bacteria found in water that is spread by the oral-fecal route and preferentially burrows into the mucosal surface of the stomach, where it causes toxic effects through ammonia production and causing antral cells to react by producing more gastrin, overabundance of parietal cells, and acid. It can lead to chronic gastritis and encourage development of ulcers and even cancer.
Also, the story of how it was discovered is pretty cool, although definitely not IRB-approved.
Who should be tested for H. pylori?
- People <55 who have dyspepsia (but no alarm symptoms that require further workup!)
- long-term PPI therapy
- unexplained iron or B12 deficiency
- A past or present diagnosis of peptic ulcer disease
- gastric MALT lymphoma
What’s the best way to diagnose H. pylori? There are several methods available: serum, stool, breath test, biopsy. Each has pros and cons, but here are a couple of key points. The breath test is both highly specific and sensitive. Biopsy is actually not as accurate (because of sampling error) but is helpful to do if you’re doing an EGD anyway, and can be used to see if there is any associated gastritis or ulcer formation. The serum test is also not as reliable (can’t distinguish between past and present infection). Patients with recent GI bleeding or who are already on PPI therapy may have false negative results.
What are the treatment regimens?
Triple therapy is most commonly prescribed in the US. It consists of: PPI BID, amoxicillin 1 g daily, and clarithromycin 500 mg BID for 7-14 days. Metronidazole can be substituted if there is a penicillin allergy. However, if triple therapy fails, quadruple therapy should be used: PPI, bismuth, and two antibiotics, usually tetracycline and metronidazole.
It should be noted that initial treatment fails in 20-30% of patients, and so there are a number of alternatives, like using doxycycline, levofloxacin, and various other agents.
Who should get retested for confirmation of eradication?
- persistent symptoms despite treatment
- people found to have H.pylori-associated peptic ulcer or MALT lymphoma
- this should take place >4 weeks after treatment ends