This test is used to diagnose bacterial infections that cause stomach ulcers.
Helicobacter pylori are bacteria that are very common in the general population and the most frequent cause of stomach ulcers. Several tests exist for directly detecting H. pylori bacteria in the stomach (breath tests, stool antigen tests). The serology test consists of screening for H. pylori antibodies in the bloodstream. When the antibody screen is negative, it is highly unlikely that the bacteria are present. Given how common the bacteria are in the general population (only a small number of people will eventually develop ulcers) and the fact that the antibodies can remain in the bloodstream for decades after the bacteria have disappeared, a positive screen for H. pylori antibodies does not distinguish a current infection requiring antibiotics treatment from a resolved previous infection. A positive antibody screen should therefore be confirmed by a breath or stool antigen test.