Isoniazid resistance is the commonest form of drug-resistant TB globally, yet there is limited access to diagnostic tests in high-burden settings.

We are undertaking an evaluation of the GeneXpert XDR cartridge, a rapid PCR-based diagnostic test, to detect isoniazid resistant tuberculosis in Vietnam. We will screen patients at risk of isoniazid resistant tuberculosis, using both Xpert and phenotypic drug susceptibility testing. The diagnostic accuracy, feasibility and time to test results will be evaluated. The project is currently ongoing in Vietnam, as a part of the FLIRT clinical trial.