New tools and policies herald a major advance in tuberculosis diagnosis

For decades, tuberculosis (TB) care has relied heavily on sputum samples and smear microscopy, making diagnosis the weakest part of the TB cascade of care.^1–3 In adults, an estimated quarter of people with presumptive TB are unable to provide sputum samples, and the limitations of microscopy, especially low sensitivity, are well known.^4,5

Recognising this, in 2023, World Health Organization (WHO) published a new standard for universal access to rapid tuberculosis diagnostics, which recommends that: (i) facilities in all districts require the use of a WHO-recommended rapid diagnostic (WRD) as the initial diagnostic test for all individuals with presumed TB, (ii) all primary healthcare facilities have access to WRDs, (iii) all individuals with presumptive TB receive initial WRD testing, and (iv) that all clinicians have access to WRD test results to guide patient management.⁶

The WHO diagnostic standard urges all countries to accelerate the transition from smear microscopy to WRDs. While existing molecular WRDs have expanded access to quality TB and drug resistance testing services, cost and infrastructure requirements (among other factors) limit their use and continued scale-up in peripheral settings where most patients seek care. Fifteen years after the WHO endorsement of the Xpert MTB/RIF (Cepheid Inc, California, USA) test, less than 50% of people newly diagnosed with TB in 2024 were initially tested with a molecular WRD.⁷ Affordable, fit-for-purpose testing approaches have become exceedingly important, particularly as funding for global health and development becomes increasingly constrained.⁸ To meet these needs, new tests, sample types, and testing strategies are now recommended to change the landscape of what is possible for TB testing in 2026.