Targeted TB screening finds more cases but national impact unclear

Tuberculosis (TB) remains a stubborn global health problem, and researchers have long debated how best to find people who have the disease. One approach, passive case-finding (PCF), relies on people with symptoms presenting to health services. Another, active case-finding (ACF), seeks out people at risk through organized screening. To untangle a growing but fragmented literature, a team with Sonia Menon as corresponding author carried out an umbrella review of systematic reviews and meta-analyses published through March 30, 2025. The goal was to bring together evidence comparing ACF and PCF and to compare different ACF strategies across settings. The review concentrated on key outcomes that matter to patients and health systems: diagnostic yield (how many cases are found), treatment outcomes, cost-effectiveness, and whether ACF changes the overall course of TB in populations. Because previous studies used many different methods, the authors also assessed the quality of the reviews themselves to help readers understand how much confidence to place in the findings.

The review included twelve systematic reviews and meta-analyses and evaluated their methodological quality using the AMSTAR 2 tool. Across those reviews, ACF tended to increase TB detection rates compared with PCF, particularly when focused on high-risk groups such as migrants, people living with HIV, drug users, and close contacts of TB patients. Treatment outcomes for people found through ACF were mixed, and the authors highlighted worries about pre-treatment loss to follow-up—people identified by screening who never start treatment. Economic analyses showed ACF interventions could be cost-effective in high-prevalence settings, but cost-effectiveness varied with how widely and intensively programs were implemented and which screening tools were used. Importantly, the umbrella review found limited evidence that ACF leads to sustained increases in national routine TB notifications, leaving uncertainty about long-term epidemiological impact.

What this synthesis means for policy and practice is straightforward but nuanced. ACF appears to be a valuable tool when targeted at people at highest risk of TB and can often justify its cost in settings with a heavy TB burden. At the same time, expanding ACF broadly without attention to coverage, intensity, follow-up systems, and the choice of screening tools may not deliver a clear national benefit. The authors call for integrated, context-sensitive strategies that combine active and passive approaches, supported by measures to reduce pre-treatment loss to follow-up and to maintain program coverage. Future research should move beyond asking whether ACF finds more cases and focus on whether it leads to sustained reductions in TB prevalence and transmission over time, so that investments can be judged by their long-term public health impact.