helicobacter%20pylori%20infection
HELICOBACTER PYLORI INFECTION
Helicobacter pylori is a spiral-shaped gram-negative bacterium involved in the development of gastritis, duodenal and gastric ulcers, and gastric cancer.
Infection is strongly associated with the development of gastric epithelial and lymphoid malignancies.
Acute infection is mostly asymptomatic and is acquired through human-to-human contact via gastro-oral and fecal-oral routes.
Adaptability in gastric conditions and production of urease allow it to colonize the stomach.

Evaluation

  • Thorough history and physical exam should be done to rule out other causes for dyspeptic symptoms [eg cardiac, hepatobiliary, medication induced eg nonsteroidal anti-inflammatory drugs (NSAIDs), dietary indiscretion, lifestyle, etc]
  • Patients with dominant symptoms of heartburn or acid regurgitation without a history of peptic ulcer disease (PUD) need not be tested for H pylori infection but should be treated for gastroesophageal reflux disease (GERD)
    • Please see Gastroesophageal Reflux Disease disease management chart for further information
  • In H pylori-infected patients, the risk of ulcer disease is increased with NSAID and aspirin use 
    • Eradication of H pylori in patients on long-term NSAID use does not enhance the healing of gastric or duodenal ulcers and these patients should be treated appropriately for NSAID-induced ulcer
    • Please see Peptic Ulcer Disease disease management chart for further information

Assessment

Patients with alarm symptoms require prompt endoscopic investigation

  • Unexplained weight loss or anorexia
  • Recurrent vomiting
  • >50 years old (cut-off age will depend on national cancer incidence rates)
  • Evidence of gastrointestinal bleeding, iron-deficiency anemia, idiopathic thrombocytopenic purpura, vitamin B12 deficiency, or positive occult blood test 
  • Dysphagia or odynophagia
  • Failure of multiple treatments
  • Jaundice
  • Presence of abdominal mass

Screening

“Test and Treat” for Helicobacter pylori in Primary Care

  • Routine testing is not recommended, performed only in patients who will require therapy if results are positive
  • Two positive tests are required for H pylori diagnosis
  • Urea breath test (UBT) and stool antigen test are the preferred methods of diagnosis in the primary care setting
    • If UBT and stool antigen test are not available, serological test (mainly IgG) is a satisfactory alternative
  • A delayed test (either a UBT or histology) should be done within 4-8 weeks of an acute upper gastrointestinal bleed following a negative endoscopy
  • In cases where an endoscopy is indicated and biopsy is not contraindicated, a rapid urease test is recommended as primary diagnostic test  
  • Pepsinogen serology may be considered in patients with antrum-restricted atrophy to evaluate the status of the gastric mucosa & as a marker for atrophic gastritis
METHODS OF H PYLORI TESTING
MODALITY ADVANTAGES DISADVANTAGES
Noninvasive
Urea breath test (UBT) Highly specific & sensitive
Reliable, inexpensive, rapid, quantitative
Gold standard test for asymptomatic patients
Most valuable for assessing response to therapy after 4-8 weeks
Useful for eradication confirmation
Allows detection of bleeding
Rarely w/ false-positive results due to urease-positive organisms
Provides no information about antibiotic resistance
Stool antigen test Highly specific & sensitive
Rapid, simple & can be modified
Enzyme-linked immunosorbent assay (ELISA) is the most accurate
Requires withholding of some medications prior to testing
Serology Rapid, quantitative, inexpensive
Recommended for initial screening
Not affected by gastric bleeding
Low sensitivity specificity
Not for eradication confirmation
Does not distinguish between active & past infection
Invasive
Endoscopy with biopsy and rapid urease test (RUT) Endoscopy:
Permits inspection of pathology
Allows detection of ulcers, neoplasm
RUT:
Highly sensitive and specific
Rapid
Inexpensive
Most handful test in a clinical setting
Endoscopy:
Invasive, expensive
Unable to visualize H pylori
RUT:
Requires withholding of some medications prior to testing
Culture Highly specific
Permits determination of antimicrobial susceptibility
Low sensitivity
Expensive
Time-consuming
Expert personnel & care during transport required
PPI and antibiotic use increase chances of false-negative result
Histology Highly specific, simple and inexpensive
More sensitive than culture
Allows direct visualization of organism extent
Several days for result
Nature of tissue involvement
With high rate of false-negative results
Polymerase chain reaction (PCR) Very good specificity sensitivity
- Liquid phase (DNA-enzyme immunoassay) and reverse dot blot probe assay (LiPA) increase PCR's specificity and sensitivity
Rapid and accurate results
Permits determination of antimicrobial susceptibility and virulence typing
Expensive
Expert personnel and longer time to process required
Not widely available
Digital Edition
Asia's trusted medical magazine for healthcare professionals. Get your MIMS Gastroenterology - Malaysia digital copy today!
Sign In To Download
Editor's Recommendations
Most Read Articles
4 days ago
New drug application approved by US FDA as of 01 - 15 September 2019 which includes New Molecular Entities (NMEs) and new biologics. It does not include Tentative Approvals. Supplemental approvals may have occurred since the original approval date.