Which noninvasive test currently provides the best detection of Helicobacter pylori infection?

• A. Stool antigen test
• B. Urea breath test
• C. Endoscopy with biopsy
• D. Serology for H. pylori antibodies

Answer: (B)

The best noninvasive test for detecting Helicobacter pylori currently is the urea breath test. It works by giving the patient labeled urea; if H. pylori is present, its urease enzyme breaks down the urea to produce CO2 that is labeled and show up in the breath. This directly indicates active infection rather than past exposure, and it has very high sensitivity and specificity, making it more reliable than tests that can’t distinguish current infection, such as antibodies. The stool antigen test is also noninvasive and accurate, but the urea breath test is generally preferred for initial diagnosis and for confirming eradication after therapy (once any interfering medications are paused). Endoscopy with biopsy is invasive, and serology can’t tell if the infection is still present. So the urea breath test best combines noninvasiveness with strong accuracy for active infection.