New swab tests show promise for faster TB detection in Cameroon

Tuberculosis remains a major global health problem, but many places still lack affordable, fast molecular tests that can be used outside advanced laboratories. Cost and infrastructure needs limit access to current rapid molecular diagnostic testing for tuberculosis. To explore alternatives that could be used closer to the point of care, researchers led by Cyrille Mbuli evaluated two newer, swab-based assays that could be simpler to roll out in clinics and community screening events. The team conducted a diagnostic accuracy study in Cameroon among people aged 15 and older who were seen at health facilities or took part in active case-finding events in the community. Each participant was asked to provide two tongue swabs and sputum specimens. The goal was to compare the new assays against the established reference standard of TB culture and see whether these less invasive, easier-to-collect samples could reliably detect tuberculosis.

Between February and June 2025, the study enrolled 1,097 participants, with 382 from community events and 715 from health facilities. The tests under evaluation were Molbio Truenat MTB Ultima (MTB Ultima) and Pluslife MiniDock MTB Test (MiniDock MTB). Comparator tests included smear microscopy and Xpert MTB/RIF Ultra, and TB culture served as the reference standard. Among 132 people with culture-positive TB, MiniDock MTB showed sensitivities of 86% (95% CI, 79-91%) using sputum and 76% (95% CI, 68-82%) using tongue swabs; among those with smear-negative TB the sensitivities were 67% (95% CI, 51-79%) for sputum and 44% (95% CI, 29-59%) for tongue swabs. For MTB Ultima, sensitivities were 84% (97/116, 95% CI, 76-89%) with sputum and 74% (67/91, 95% CI, 64-82%) with tongue swabs; in smear-negative TB the sensitivities were 58% (95% CI, 41-74%) for sputum and 33% (95% CI, 18-53%) for tongue swabs. Both tests showed high specificity, greater than 97%.

The findings indicate that both MiniDock MTB and MTB Ultima, when used on tongue swabs and sputum, achieved diagnostic performance similar to established target product profile thresholds for near point-of-care TB tests. High specificity suggests these assays are unlikely to give many false positives, while the moderate-to-high sensitivities, especially on sputum, point to real potential for detecting cases that might otherwise be missed by smear microscopy. Importantly, the use of tongue swabs could make sample collection easier in community and clinic settings where collecting good sputum samples is difficult. The authors conclude that these swab-based approaches could help expand access to rapid TB testing close to where people live and seek care, but they also call for further studies to confirm performance in diverse populations and different health system settings before widespread rollout.