Breakthrough approach for TB screening could significantly improve detection
A new strategy for tuberculosis (TB) screening, proposed by a team of researchers led by Dominik Zenner (WIPH), provides a solution to the problem of current TB screening not always accurately detecting disease. Simultaneously screening for both active and dormant TB infection could save lives, curtail infection rates, and rewrite the story of the continued spread of this disease. Researchers hope that this new approach will inform guidance from global health organisations and key decision-makers on the most effective way to screen for TB.
TB is the deadliest infectious diseases globally, with 10.8 million new cases and 1.25 million deaths in 2023. Effective screening is an important intervention to prevent its spread. TB can remain dormant in the body for years without causing symptoms, but may cause active disease in the future, especially among certain people at high risk. Accurate testing of both active and dormant infection is therefore of critical importance in screening programmes.
This study analysed the efficacy of combinations of commonly used tests for TB. Researchers examined data on 13 different TB tests, described in 437 original studies and published systematic reviews. The data were then used to estimate how well screening tests correctly identified TB and avoided false positive results. The research found that including some immunological tests for dormant TB infection (TBI tests) added value to TB screening algorithms. TBI tests could also support earlier diagnosis of harder to detect TB, including extrapulmonary TB (disease that occurs outside the patient’s lungs), or TB in children.
This novel approach challenges existing protocols for TB testing, which reserve TBI tests for diagnosing only dormant TB. Importantly, combining diagnostic tests for both dormant and active TB would allow for both forms of the disease to be detected concurrently. This opportunity to improve detection of TB across large populations should be of interest to policy makers and public health organisations, including WHO and the European Centre for Disease Prevention and Control.
Lead researcher, Dominik Zenner, said: ‘Global TB control requires early identification and treatment of TB in risk groups. Our novel screening algorithms show that screening for active and dormant TB can be done simultaneously with high accuracy for migrants from countries where TB is common to improve individual and population benefits.’
Mario Raviglione, former Director of the Global Tuberculosis (TB) Programme at the World Health Organization and currently Professor of Global Health at the University of Milan, said: ‘This is a very sophisticated and well-thought study with major implications for clinical and public health practice, as well as policy change. By reviewing sound evidence and applying modern statistical methods, the authors have concluded that adopting an Interferon Gamma Release Assay (IGRA) test - a blood test that detects the response of white blood tests to TB antigens - on top of more traditional TB screening methods, the accuracy of screening migrants for active TB increases significantly.’
Zenner D, Haghparast-Bidgoli H, Chaudhry T, Abubakar I, Cobelens F. How to diagnose TB in migrants? A systematic review of reviews and decision tree analytical modelling exercise to evaluate properties for single and combined TB screening tests. Eur Respir J. 2025 Apr 23:2402000. doi: 10.1183/13993003.02000-2024. Epub ahead of print. PMID: 40268506.