A prospective multicentre diagnostic accuracy study for the Truenat tuberculosis assays

Background Bringing reliable and accurate tuberculosis (TB) diagnosis closer to patients is a key priority for global TB control. Molbio Diagnostics have developed the Truenat point-of-care molecular assays for detection of TB and rifampicin (RIF) resistance. Methods We conducted a prospective multicentre diagnostic accuracy study at 19 primary healthcare centres and seven reference laboratories in Peru, India, Ethiopia and Papua New Guinea to estimate the diagnostic accuracy of the point-of-care Truenat MTB, MTh Plus and MTB-RIF Dx assays for pulmonary TB using culture and phenotypic drug susceptibility testing as the reference standard, compared with Xpert MTB/RIF or Ultra. Results Of 1807 enrolled participants with TB signs/symptoms, 24% were culture-positive for Mycobacterium tuberculosis, of which 15% were RIF-resistant. In microscopy centres, the pooled sensitivity of Truenat MTB and Truenat MTB Plus was 73% (95% CI 67-78%) and 80% (95% CI 75-84%), respectively. Among smear-negative specimens, sensitivities were 36% (95% CI 27-47%) and 47% (95% CI 37-58%), respectively. Sensitivity of Truenat MTB-RIF was 84% (95% CI 62-95%). Truenat assays showed high specificity. Head-to-head comparison in the central reference laboratories suggested that the Truenat assays have similar performance to Xpert MTB/RIF. Conclusion We found the performance of Molbio's Truenat MTB, MTB Plus and MTB-RIF Dx assays to he comparable to that of the Xpert MTB/RIF assay. Performing the Truenat tests in primary healthcare centres with very limited infrastructure was feasible. These data supported the development of a World Health Organization policy recommendation of the Molbio assays.

Automated summary

The study found that Molbio's Truenat assays performed comparably to Xpert in diagnosing pulmonary tuberculosis, and testing at primary healthcare centers with limited infrastructure was feasible. These findings supported the development of World Heath Organization policy recommendations for the Molbio assays.