MDR-TB Treatment & Prevention
Pathways to better diagnostics for tuberculosis: A blueprint for the development of TB diagnostics
This publication is intended to help tuberculosis diagnostics researchers work more effectively with academics, officials and industry professionals. It offers a structure to guide those involved in diagnostic development through the different phases of development – from the discovery of new techniques and tools through to their delivery in previously neglected markets. It is designed to help identify the most promising TB tests, to push them toward alignment with the needs and requirements of the areas where tuberculosis is most prevalent, and to help determine why some are held up in development. The blueprint also is intended to help boost coordination and collaboration across the diagnostic research and development landscape, while leading to greater success in advancing new tests by clarifying that landscape and the various development steps. Finally, considering the paucity of national regulations regarding the quality of diagnostics and the need for a strong evidence base to support health policy decisions, this blueprint seeks to inform and advance independent evaluation and assessment of the new tools’ likely impacts based on scientifically sound methodology, in addition to well-defined standards of practice for study design.
Increasing the speed, effectiveness and accuracy of diagnostic tests is central to the goal of rolling back the global tuberculosis epidemic that afflicts nearly a third of the world’s population. Though recent and ongoing advancements in drug therapies offer great promise for saving lives, the unfortunate fact is that new medicines have limited value in the places where TB is rampant. This is because the principal diagnostic tools used in developing countries for determining whether someone has tuberculosis – microscopic examination of stained sputum and chest X-ray – are simply not accurate enough to identify many TB infections. In addition, many poor and
vulnerable people lack access to even these basic diagnostic tools and so do not find out what is wrong with them until it is too late to successfully treat the disease, and until long after they are likely to have transmitted the disease to others.
The problem is that the cost and sophistication of current new diagnostic tools limit their application to specialized reference laboratories, even in industrialized countries. What is required are far simpler, accurate point of care tests that can be used in remote health centres to reach the majority of tuberculosis sufferers. Affordability (to the health system) and accessibility (to individuals with suspected TB) as well as high sensitivity are central to determining the impact of any diagnostic test and its ability to accurately diagnose tuberculosis in as many patients as possible.
Contents:
Contributors
Glossary
Executive Summary
Introduction: delivering diagnostics, from concept to delivery
1. The search for tubercle bacilli
2. TB diagnosis today: the search for improved diagnostics continues
3. The current TB epidemic
4. The rationale for the diagnostic
5. Assessing the needs
6. Aiming for the right targets
7. Feasibility – A guarantee of strong foundations
8. Development and optimization: additional hurdles
9. Evaluation, putting it through its paces: does the test work?
10. Demonstration, putting the test to the test: is it worth it?
11. Measuring impact
12. Access: the final test of success
13. Barriers and challenges
14. References
Annexes - see CD in back cover
The principles of current TB diagnostic tools
1. Optimizing TB smear microscopy
2. Rapid solid and liquid culture
3. Antigen detection tests for diagnosis of active TB
4. Antibody detection
5. T-cell-based interferon-gamma release assays
6. Nucleic acid amplification tests
7. Molecular drug resistance testing
8. Phage-based tests
9. Nose technologies
10. References and glossary
Attached resource:
