What is the best diagnostic test for Helicobacter (H.) Pylori infection?

From the Guidelines

The most reliable diagnostic test for H. pylori is the urea breath test, which offers high sensitivity and specificity (over 95%) with minimal invasiveness. For initial diagnosis, this test or the stool antigen test are preferred non-invasive options 1. The stool antigen test is particularly useful for children or when breath testing isn't available. If endoscopy is already planned for other reasons, a biopsy-based test with rapid urease testing or histology provides direct evidence of infection.

Key Considerations for Diagnostic Testing

• Serological blood tests, while convenient, cannot distinguish between current and past infections, making them less useful for confirming active infection or verifying eradication 1.
• For post-treatment confirmation of eradication, the urea breath test or stool antigen test should be performed at least 4 weeks after completing antibiotics and 2 weeks after stopping proton pump inhibitors to avoid false negatives 1.
• The choice between tests should consider local availability, cost, patient factors, and whether the patient has recently taken antibiotics or acid-suppressing medications 1.
• Recent use of antibiotics, bismuth, or proton pump inhibitors can lead to false-negative results, and it is recommended to withhold these medications for at least 2 weeks before testing 1.

Test Characteristics

• Urea breath test: sensitivity and specificity of over 95% 1.
• Stool antigen test: sensitivity and specificity of more than 90% 1.
• Serological tests: remain positive long after the infection has been eradicated, and therapeutic decisions should not entirely rely on the results of serologic testing 1.

From the Research

Diagnostic Tests for Helicobacter Pylori Infection

• The choice of diagnostic test for Helicobacter pylori infection depends on the clinical situation and the availability of tests 2, 3.
• Invasive tests, such as histological detection, culture, and polymerase chain reaction (PCR), are highly accurate but require endoscopy and biopsy 2.
• Non-invasive tests, such as serology, urea breath test, and stool antigen test, are less sensitive but more convenient and less expensive 2, 3, 4, 5, 6.

Characteristics of Diagnostic Tests

• The urea breath test is a simple, safe, and highly accurate method for evaluating the short-term follow-up of H. pylori eradication after therapy 4.
• Serology is a widely used non-invasive test, but its use is not advised in post-treatment follow-up 4.
• The stool antigen test (HpSA) has a sensitivity of 65% and a specificity of 76% compared to the CLO test 5.
• The CLO test is considered the best diagnostic test for H. pylori detection in some settings 5.

Test Selection

• The choice of test depends on the pre-test probability of infection, the characteristics of the test being used, and the cost-effectiveness of the test 6.
• Non-invasive test-and-treat strategies are widely recommended in primary care settings 6.
• The urea breath test and the stool antigen test are considered "active tests" that detect active infection, while serology is a "passive test" that indicates exposure to H. pylori but not active infection 6.