What are the methods for diagnosing Helicobacter pylori (H. pylori) infection?

From the Guidelines

Helicobacter pylori (H. pylori) infection can be diagnosed using various methods, including invasive and non-invasive techniques.

Methods of Diagnosis

The methods for diagnosing H. pylori infection include:

• Invasive techniques:
  • Histologic examination of biopsy samples taken during endoscopy
  • Culture
  • Polymerase chain reaction (PCR)
• Non-invasive techniques:
  • Serology: testing for anti-H. pylori IgG antibodies, although this method is not recommended due to its low specificity and sensitivity 1
  • Urea breath test (UBT): measures the amount of labeled CO2 in the breath, an expression of the urease activity of the bacterium 1
  • Stool antigen test: detects the presence of bacterial antigens in stool 1
  • Urine or blood tests: detection of H. pylori antigen in urine or blood

Choosing the Right Test

The choice of test depends on the clinical circumstances, likelihood ratio of positive and negative tests, cost-effectiveness of the testing strategy, and availability of the tests 1.

• Non-invasive tests are preferred for patients with uninvestigated dyspepsia, while invasive tests may be necessary for patients with alarm symptoms or those who have failed eradication therapy 1.
• Urea breath test and stool antigen test are commonly used non-invasive tests, with high sensitivity and specificity 1.

It is essential to consider the pre-test probability of the infection in the population, age of the patients, present complaints, and past medical history when choosing a diagnostic test 1. Additionally, economic evaluations should be taken into account to assess the costs and consequences of the alternative strategies for the detection and management of H. pylori infection 1.

From the Research

Diagnostic Methods for Helicobacter pylori Infection

The diagnostic methods for Helicobacter pylori (H. pylori) infection can be categorized into invasive and non-invasive techniques, each with its own advantages and disadvantages 2, 3, 4, 5, 6.

• Invasive methods:
  • Endoscopy with biopsies of gastric tissues for histology, culture, and rapid urease test 2, 4, 5
  • Endoscopic imaging, including visual endoscopy using blue laser imaging (BLI), linked color imaging (LCI), and magnifying endoscopy 5
• Non-invasive methods:
  • Urea breath test, a quick diagnostic procedure with comparable accuracy to biopsy-based techniques 2, 3, 5
  • Fecal antigen tests, a method of choice in the test and treatment setting 2, 3
  • Serological methods to detect immunoglobulin G antibodies to H. pylori, which can show high accuracy but do not differentiate between current or past H. pylori infections 2, 4, 5
  • Molecular methods, such as polymerase chain reaction (PCR), which can be categorized as invasive and non-invasive tests 2, 3, 5

Selection of Diagnostic Methods

The selection of one or more diagnostic tests depends on various factors, including clinical conditions, the experience of the clinician, cost, sensitivity, and specificity 2, 4, 5.

• The test-and-treat strategy, endoscopy-based strategy, and screen-and-treat strategy are recommended to prevent gastric cancer based on risk stratification, prevalence, and patients' clinical manifestations and conditions 3
• Recent advances in diagnostic methods, such as image-enhanced endoscopy (IEE), artificial intelligence (AI) technology, and quantitative real-time polymerase chain reaction (qPCR) and digital PCR (dPCR), aim to improve the accuracy and effectiveness of H. pylori diagnosis 3, 5