Helicobacter pylori
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 by the American College of Gastroenterology guide treat.[5]
Regarding which patient to treat:
- "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". A subsequent randomized controlled trial showed benefit of eradication to prevent gastric cancer in a high risk region.[6]
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[7] due to prior exposure of patients to macrolide antiobiotics and metronidazole.[8]
- "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".
History
Barry Marshall and Robin Warren won the 2005 Nobel Prize in Physiology or Medicine for discovery of Helicobacter pylori in 1983.[9][10]
References
- ↑ Soll AH (1990). "Pathogenesis of peptic ulcer and implications for therapy". N. Engl. J. Med. 322 (13): 909–16. PMID 2179722. [e]
- ↑ 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
- ↑ 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]
- ↑ 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]
- ↑ 5.0 5.1 5.2 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.
- ↑ 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.
- ↑ 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.
- ↑ 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]
- ↑ 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.
- ↑ 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]