A study published in the European Respiratory Journal presents a comprehensive assessment of tuberculosis (TB) diagnostic strategies for migrant populations, highlighting the value of integrating TB infection (TBI) tests into screening pathways.
Specifically, including an interferon gamma release assay (IGRA) test – a blood test that detects the response of white blood cells to TB antigens – alongside more traditional TB screening methods, improved the screening performance.
Researchers evaluated 18 TB diagnostic tests across 437 studies, synthesizing data from 32 systematic reviews. The analysis focused on test sensitivity, specificity, and diagnostic odds ratios (dORs) – essential metrics for assessing diagnostic performance. Tests involving IGRAs as an initial screening step, followed by chest X-ray and molecular assays, yielded the highest dORs and positive predictive values.
Three-test combinations generally outperformed two-test strategies, with those involving parallel symptom/chest X-ray screening followed by molecular confirmation achieving top sensitivity scores.
The findings point to the clinical potential of IGRAs beyond latent TB infection screening, particularly when deployed early in multi-step screening algorithms. While implementation may depend on local logistics and cost considerations, the modeling framework allows for adaptation across diverse settings.
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.”