The evolving diagnostic landscape for tuberculosis, Pg8

Key Highlights:

• The WHO recently recommended new near point-of-care (NPOC) molecular tests for TB diagnosis, along with tongue swab samples and sputum pooling strategies.
• India's NTEP is utilizing hundreds of portable CXR machines for active TB screening in communities under the Pradhan Mantri TB Mukt Bharat Abhiyaan.
• AI algorithms in digital X-ray machines can identify suspicious lesions for TB and other respiratory disorders, reducing delays in diagnosis.
• India is scaling up molecular testing with CBNAAT and Truenat, but access remains uneven, requiring strengthened sputum collection and transportation.

Detailed Insights:

• The diagnostic landscape for TB is evolving rapidly with new technologies being tested and utilized to advance global elimination efforts.
• Portable CXR with AI is enabling active case-finding in communities, but on-the-spot sputum collection is crucial to reduce attrition in the diagnostic cascade.
• Opportunistic screening using AI in public and private clinics can reduce delays in diagnosis of TB and other respiratory disorders.
• While India has scaled up molecular testing, achieving 100% testing through NAAT requires strengthening sputum collection and transportation mechanisms.
• WHO's endorsement of nPOC-NAAT provides more options for molecular testing at the primary-care level, especially with non-sputum samples like tongue swabs.
• Diagnostic network optimization can help identify the best tools and their locations to establish an accessible, affordable, and person-centered diagnostic cascade.
• Research is needed for cost-effective biomarkers to identify those at high risk for disease progression as India scales up testing for TB infection and access to TB preventive therapy (TPT).
• Diagnosing extra-pulmonary TB (EP-TB) remains difficult and expensive, requiring India-specific evidence on the use of AI-enabled portable ultrasound devices alongside molecular testing.
• Investing in strengthening the diagnostic landscape can improve treatment outcomes, reduce transmission, and lower out-of-pocket expenditure for families affected by TB.

Key Concepts Involved:

• CBNAAT (Cartridge-based Nucleic Acid Amplification Test): A molecular test for rapid detection of TB and drug resistance.
• NAAT (Nucleic Acid Amplification Test): A molecular test that detects the genetic material of TB bacteria.
• TB Preventive Therapy (TPT): Treatment given to individuals with TB infection to prevent progression to active disease.