Quality Assurance Program for ¹⁴C-Urea Breath Testing

To the Editor:
Helicobacter pylori infection continues to be a major health problem worldwide, causing considerable morbidity and mortality due to peptic ulcer disease and gastric cancer. Urea breath tests (UBTs) have higher diagnostic accuracy than other non-invasive tests for identifying H. pylori (in patients without a history of gastrectomy) (1). Patients as well as healthcare and laboratory workers may have a lower preference for stool-based tests (stool antigen testing) (2).

While 13C-UBT is often preferred in well-resourced regions, the unit cost of 14C-UBT is lower and the test could be provided at a low cost using a central laboratory “hub-and-spoke” model for service delivery (2). False-positive tests could occur in patients who have hypochlorhydria or may be due to other bacteria with urease activity (3).

The total testing process of 14C-UBT includes collection of a patient breath sample (containing carbon dioxide, CO2), transfer of the breath sample including CO2 to collection fluid, and analysis of 14CO2 by a scintillation counter. The interpretation of results (disintegrations per min, DPM) as suggested by the manufacturer (Tri-Med, Perth, Australia) are: <50 DPM (negative for H. pylori), 50 to 199 DPM (borderline positive), >200 DPM (positive).