Also known as: H. pylori, Helicobacter pylori, HP infection
Overview
Chronic infection of the gastric mucosa by Helicobacter pylori, a microaerophilic, urease-producing, Gram-negative spiral bacterium. Classified by WHO/IARC as a Group 1 carcinogen.
Epidemiology
Estimated to colonize ~50% of the global population; prevalence 30-40% in the US (higher in immigrants, lower socioeconomic groups, and elderly). Acquired in childhood, typically via fecal-oral or oral-oral transmission. Declining incidence in developed countries.
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Question 1GastrointestinalEasy
A 55-year-old man is admitted with hematemesis. Upper endoscopy shows a clean-based duodenal ulcer with no active bleeding, and gastric biopsy is positive for Helicobacter pylori. Which of the following is the most important long-term management?
Why H. pylori eradication with confirmation testing is correct
In H. pylori-positive peptic ulcer disease, eradicating the organism is the single most important long-term step because it treats the underlying cause and cuts the annual ulcer recurrence rate from roughly 60-70% to under 5%
First-line therapy is bismuth quadruple therapy, or clarithromycin-based triple therapy where macrolide resistance is low, given for 14 days
Cure must be confirmed at least 4 weeks after completing antibiotics, with the patient off PPI for 1-2 weeks, using a urea breath test or stool antigen test (serology cannot confirm eradication); per current ACG guidance, confirmation of eradication is required after treating complicated disease such as a bleeding ulcer
Why the others are wrong
Repeat upper endoscopy at 2 weeks — Routine repeat endoscopy is reserved for gastric (not duodenal) ulcers to exclude malignancy; it does nothing to lower recurrence and is not the long-term priority (buzzword-matching ulcer to surveillance scope)
Surgical vagotomy — Acid-reducing surgery has been made nearly obsolete by H. pylori eradication and PPIs and is reserved for refractory or complicated disease (anchoring on an outdated definitive procedure)
Indefinite proton pump inhibitor (PPI) monotherapy — Continuous acid suppression heals the ulcer but leaves the H. pylori infection untreated, so ulcers recur once it is stopped; it is not a substitute for eradication (right-direction-wrong-step)
Question 2GastrointestinalMedium
A 55-year-old man with recurrent peptic ulcers undergoes upper endoscopy showing a 1.5 cm duodenal ulcer and tests positive for Helicobacter pylori by urea breath test. He is treatment-naive for H. pylori, local clarithromycin resistance is unknown, and he takes aspirin 81 mg for coronary artery disease. Which of the following is the most appropriate first-line eradication regimen?
APPI plus bismuth plus tetracycline plus metronidazole for 14 days
BPPI plus amoxicillin dual therapy for 10 days
CPPI plus clarithromycin plus metronidazole for 7 days
DPPI plus clarithromycin plus amoxicillin for 14 days
Reveal answer & full explanation
Correct answer: A — PPI plus bismuth plus tetracycline plus metronidazole for 14 days
APPI plus bismuth plus tetracycline plus metronidazole for 14 days✓
BPPI plus amoxicillin dual therapy for 10 days
CPPI plus clarithromycin plus metronidazole for 7 days
DPPI plus clarithromycin plus amoxicillin for 14 days
Why PPI plus bismuth plus tetracycline plus metronidazole for 14 days is correct
Eradicating H. pylori reduces peptic ulcer recurrence from roughly 80% to under 10% at 1 year, so successful first-line therapy is the priority
He is treatment-naive with unknown local clarithromycin resistance; the ACG (2017) and Maastricht VI guidelines no longer endorse empiric clarithromycin triple therapy unless susceptibility is confirmed or local resistance is known to be below 15%
Bismuth quadruple therapy (PPI + bismuth + tetracycline + metronidazole) for 14 days is a preferred first-line regimen that does not depend on clarithromycin susceptibility and reliably covers macrolide-resistant strains
It is also macrolide-sparing, avoiding the high failure rates seen with empiric clarithromycin regimens in areas of rising resistance
Why the others are wrong
PPI plus amoxicillin dual therapy for 10 days — high-dose dual therapy is an emerging alternative but is not the preferred guideline first-line and underperforms quadruple therapy at this duration (premature adoption)
PPI plus clarithromycin plus metronidazole for 7 days — empiric clarithromycin triple therapy is discouraged when resistance is unknown, and 7 days is inferior to 14 days (outdated-regimen)
PPI plus clarithromycin plus amoxicillin for 14 days — even at 14 days, empiric clarithromycin triple therapy is no longer first-line without confirmed susceptibility or known low resistance (anchoring on the classic triple)
Additional high-yield points
Stop any nonsteroidal anti-inflammatory drugs; if aspirin must continue for cardiac protection, add a once- or twice-daily PPI long term
Confirm eradication with urea breath test or stool antigen at least 4 weeks after antibiotics and at least 2 weeks off the PPI
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H. pylori diagnostic test characteristics — choose based on whether EGD is needed and recent medication exposure.
Treatment
First-line
Bismuth quadruple therapy × 14 days — PPI BID + bismuth subsalicylate QID + tetracycline 500 mg QID + metronidazole 500 mg QID — PREFERRED first-line in US (clarithromycin resistance >15% in most regions)
Clarithromycin triple therapy × 14 days — PPI BID + clarithromycin 500 mg BID + amoxicillin 1 g BID (or metronidazole if PCN-allergic) — ONLY if no prior macrolide exposure and local resistance <15%
Second-line / adjunct
Salvage regimens after first-line failure (choose a regimen the patient has NOT received):
Levofloxacin triple × 14 days — PPI BID + levofloxacin 500 mg daily + amoxicillin 1 g BID
Bismuth quadruple × 14 days (if not previously used)
Rifabutin triple × 14 days — PPI BID + rifabutin 50 mg TID + amoxicillin 1 g TID — refractory cases
Susceptibility-guided therapy after second failure
Confirm eradication 4 weeks after completing therapy by urea breath test or stool antigen
Complications
Peptic ulcer disease (duodenal > gastric)
Gastric adenocarcinoma (intestinal-type) — eradication reduces risk; most pronounced if treated before intestinal metaplasia
Gastric MALT (mucosa-associated lymphoid tissue) lymphoma — 60-80% regress with H. pylori eradication alone
Iron-deficiency anemia (refractory or unexplained)
Immune thrombocytopenic purpura (ITP)
Vitamin B12 deficiency
Functional dyspepsia symptoms (modest benefit from eradication)
PANCE pearls
Indications to test (ACG 2017): active PUD, history of PUD without prior eradication, gastric MALT lymphoma, early gastric cancer post-resection, uninvestigated dyspepsia <60 yr without alarm features, long-term NSAID/aspirin users, unexplained iron-deficiency anemia, ITP, household contacts of H. pylori carriers, family history of gastric cancer.
ALWAYS confirm eradication 4 weeks after therapy — failure rates 15-30% with first-line regimens.
Avoid clarithromycin-based regimens in patients with any prior macrolide exposure.
Bismuth turns stool and tongue BLACK — counsel patients to avoid confusing with melena.
MALT lymphoma — treat H. pylori first; surveillance EGD; chemotherapy/radiation only for non-responders or t(11;18)-positive disease.
Mass eradication is not recommended; treat only patients meeting indications.
References
ACG 2017 — Chey WD et al. ACG Clinical Guideline: Treatment of Helicobacter pylori Infection. Am J Gastroenterol 2017;112:212-239
Maastricht VI/Florence — Malfertheiner P et al. Management of Helicobacter pylori infection: the Maastricht VI/Florence Consensus Report. Gut 2022;71:1724-1762
AGA 2024 — Shah SC et al. AGA Clinical Practice Update on the Diagnosis and Management of Atrophic Gastritis. Gastroenterology 2021;161:1325-1332
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