Diagnostic accuracy of RISK6 assay in childhood pulmonary TB

Area of Science:

• Pediatric infectious diseases
• Diagnostic test development
• Global health

Background:

• The World Health Organization (WHO) updated its target product profile (TPP) for tuberculosis (TB) identification at the peripheral level to guide new test development.
• Accurate and timely TB diagnosis in children remains a significant global health challenge.

Purpose of the Study:

• To evaluate the diagnostic accuracy and cost-effectiveness of the RISK6 assay for identifying pulmonary tuberculosis (TB) in children under 15 years old.
• To compare the RISK6 assay's performance against existing diagnostic methods like the Mantoux test and chest X-ray.

Main Methods:

• A prospective diagnostic accuracy study was conducted with 365 outpatients under 15 years old suspected of having pulmonary TB.
• The study assessed the RISK6 assay's accuracy and performed a cost-per-TB case identification analysis at the International Centre for Diarrheal Disease Research, Bangladesh (icddr,b).

Main Results:

• Out of 365 children, 68 had confirmed TB, 94 had unconfirmed TB, and 203 were unlikely to have TB.
• RISK6 did not meet the WHO TPP for general pediatric TB diagnosis but excelled in identifying presumptive pulmonary TB in infants ≤ 12 months, outperforming Mantoux and chest X-ray.
• RISK6, alone or with the Mantoux test, proved cost-effective for TB identification and confirmation, especially in children over 12 months ($US132.00 per case).

Conclusions:

• While not meeting the WHO TPP for all pediatric TB cases, the RISK6 assay demonstrates potential as a triage tool.
• The RISK6 assay is particularly promising for children ≤ 12 months and can function as a decision-support tool within WHO-recommended integrated treatment algorithms.