Helicobacter pylori

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Diagnosis

Prior infection

Detection of serum antibodies against H. pylori indicate prior infection. The probability of having positive antibody test is approximately the same as the age of the patient.[1] For example, a 50 year old male has approximately a 50% chance of having antibodies against H. pylori.

Active infection

There is no one test that detects all patients infected with H. pylori.

Non-invasive tests

Clinical practice guidelines by the American Gastroenterological Association state "H. pylori testing is optimally performed by a 13C-urea breath test or stool antigen test."[2] Details of test accuracy have been reviewed.[3]

If a patient is taking anti-secretory therapy, the breath test may be falsely negative for 3-9 days after stopping pantoprazole. For patients on ranitidine, if they have been taking it for at least 30 days, they do not need a washout period.[4]

Invasive tests

H. pylori can be detected during esophagogastroduodenoscopy (EGD) by biopsy, culture, or rapid urease testing.

Treatment

Clinical practice guidelines[5] by the American College of Gastroenterology and systemical review by the UK Clinical Evidence[6] guide treatment. The recommendations conflict on treating non-ulcer dyspepsia.

Regarding which patient to treat:

  • Patients with duodenal or gastric ulcer, non-ulcer dyspepsia, people with uninvestigated dyspepsia[6]
  • "Testing is uncertain among patients with functional dyspepsia, gastroesophageal reflux disease (GERD), patients taking nonsteroidal antiinflammatory drugs, with iron deficiency anemia, or who are at risk of developing gastric cancer".[5] A subsequent randomized controlled trial showed benefit of eradication to prevent gastric cancer in a high risk region.[7]

Regarding how to treat:[5]

  • "Eradication rates achieved by first-line treatment with a proton pump inhibitor (PPI), clarithromycin, and amoxicillin have decreased to 70-85%, in part due to increasing clarithromycin resistance".
  • "Eradication rates may also be lower with 7 versus 14-day regimens."

Regarding follow-up of treatment[5], H. pylori antibiotic resistance is increasing[8] due to prior exposure of patients to macrolide antiobiotics and metronidazole.[9]

  • "Testing to prove eradication should be performed in patients who receive treatment of H. pylori for peptic ulcer disease, individuals with persistent dyspeptic symptoms despite the test-and-treat strategy, those with H. pylori-associated MALT lymphoma, and individuals who have undergone resection of early gastric cancer".
  • "For patients with persistent H. pylori consider bismuth quadruple therapy. A PPI, levofloxacin, and amoxicillin for 10 days is more effective and better tolerated than bismuth quadruple therapy for persistent H. pylori".

A complication of treatment is selecting for "highly resistant enterococci that can persist for at least 3 years ".[10]

Prevention

It has been recommended to eradicate H. pylori world wide as was done for smallpox.[11]

History

Barry Marshall and Robin Warren won the 2005 Nobel Prize in Physiology or Medicine for discovery of Helicobacter pylori in 1983.[12][13]

References

  1. ↑ Soll AH (1990). "Pathogenesis of peptic ulcer and implications for therapy". N. Engl. J. Med. 322 (13): 909–16. PMID 2179722. [e]
  2. ↑ Talley NJ (2005). "American Gastroenterological Association medical position statement: evaluation of dyspepsia". Gastroenterology 129 (5): 1753–5. DOI:10.1053/j.gastro.2005.09.019. PMID 16285970. Research Blogging. National Guideline Clearinghouse
  3. ↑ Logan RP, Walker MM (2001). "ABC of the upper gastrointestinal tract: Epidemiology and diagnosis of Helicobacter pylori infection". BMJ 323 (7318): 920–2. PMID 11668141. [e]
  4. ↑ Dulbecco P, Gambaro C, Bilardi C, et al (2003). "Impact of long-term ranitidine and pantoprazole on accuracy of [13C]urea breath test". Dig. Dis. Sci. 48 (2): 315–21. PMID 12643609. [e]
  5. ↑ 5.0 5.1 5.2 5.3 Chey WD, Wong BC (2007). "American College of Gastroenterology guideline on the management of Helicobacter pylori infection". Am. J. Gastroenterol. 102 (8): 1808–25. DOI:10.1111/j.1572-0241.2007.01393.x. PMID 17608775. Research Blogging.
  6. ↑ 6.0 6.1 Delaney B, Moayyedi P, Forman D (2005). "Helicobacter pylori infection". Clinical evidence (13): 518–34. PMID 16135272. [e]
  7. ↑ Wong BC, Lam SK, Wong WM, et al (2004). "Helicobacter pylori eradication to prevent gastric cancer in a high-risk region of China: a randomized controlled trial". JAMA 291 (2): 187–94. DOI:10.1001/jama.291.2.187. PMID 14722144. Research Blogging.
  8. ↑ Mégraud F (2004). "H pylori antibiotic resistance: prevalence, importance, and advances in testing". Gut 53 (9): 1374–84. DOI:10.1136/gut.2003.022111. PMID 15306603. Research Blogging.
  9. ↑ McMahon BJ, Hennessy TW, Bensler JM, et al (2003). "The relationship among previous antimicrobial use, antimicrobial resistance, and treatment outcomes for Helicobacter pylori infections". Ann. Intern. Med. 139 (6): 463–9. PMID 13679322. [e]
  10. ↑ Sjölund M, Wreiber K, Andersson DI, Blaser MJ, Engstrand L (2003). "Long-term persistence of resistant Enterococcus species after antibiotics to eradicate Helicobacter pylori". Ann. Intern. Med. 139 (6): 483–7. PMID 13679325. [e]
  11. ↑ Graham DY (1997). "Can therapy even be denied for Helicobacter pylori infection?". Gastroenterology 113 (6 Suppl): S113–7. PMID 9394771. [e]
  12. ↑ Parsonnet J (2005). "Clinician-discoverers--Marshall, Warren, and H. pylori". N. Engl. J. Med. 353 (23): 2421–3. DOI:10.1056/NEJMp058270. PMID 16339090. Research Blogging.
  13. ↑ Marshall BJ, Warren JR (1984). "Unidentified curved bacilli in the stomach of patients with gastritis and peptic ulceration". Lancet 1 (8390): 1311–5. PMID 6145023. [e]
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