Summary

Tuberculosis (TB) remains a major public health challenge globally as well as in Vietnam, where expanding access to rapid molecular diagnosis is essential but constrained by testing costs and laboratory capacity. In March 2026, WHO recommended, for the first time, sputum pooling with Xpert MTB/RIF Ultra as an initial diagnostic strategy for adults and adolescents when resource constraints preclude individual testing. WHO also highlighted the need to balance potential cost savings against reduced diagnostic accuracy, particularly when sputum is collected in community settings. This study provides timely, real-world evidence directly relevant to implementation of this recommendation. In 2396 adults in Vietnam, pooled Xpert-Ultra testing reduced cartridge use by 46.5%, saving USD 14 447, while maintaining high specificity, but sensitivity was lower than individual testing and substantially lower in community-based case finding. These findings demonstrate the potential of pooling to expand affordable molecular TB testing while highlighting the need for context-specific implementation and safeguards to minimize missed cases. (doi https://doi.org/10.1016/j.cmi.2026.05.026)