Diagnosis of Helicobacter pylori

There are numerous well-tried methods for the diagnosis of Helicobacter pylori. Patients should avoid antibacterial agents for 2-4 weeks prior to direct testing lest a false negative result be obtained. Direct tests include biopsy for Gram stain, culture, rapid urease test and histology, urea breath test, stool antigen test and various molecular methods on gastric material. Indirect (antibody-based) tests are also very accurate for initial diagnosis but are difficult to interpret in the previously treated patient. In most cases, the combination of a sensitive and a specific test (for example urea breath test with serology) results in high accuracy with minimal cost. Recent advances have been based on new molecular-based techniques such as polymerase chain reaction (PCR) which yield quicker results but have been difficult to introduce into the routine diagnostic laboratory.