Pre-departure TB testing and treatment could protect U.S.-bound refugees

Tuberculosis (TB) remains a serious concern for people arriving in low-incidence countries, and refugees are a population with higher exposure and barriers to care after arrival. Yuli Lily Hsieh led a team that used mathematical modelling to examine whether offering testing and treatment for latent TB infection (LTBI) before people travel to the United States could change health outcomes and costs. The study focuses on refugees coming from countries with high TB incidence and looks at health effects from the time of the pre-departure medical evaluation through a person’s lifetime. Previous work has suggested that migrants who start care before departure are more likely to complete treatment than those tested and treated only after arrival, and a recent pilot showed pre-departure testing and voluntary LTBI treatment can be done in practice. Hsieh and colleagues set out to quantify how much pre-departure services could prevent TB disease and whether those services represent good value when compared with current approaches that rely mainly on post-arrival care.

The team built a model to simulate TB-related outcomes and costs in 2023 USD for refugees from the pre-departure medical exam until death. Latent infection was diagnosed using the interferon-gamma release assay (IGRA) after ruling out TB disease. The researchers compared three strategies: Strategy 1 offered pre-departure IGRA testing for children aged 2–14 and post-arrival IGRA testing for adults older than 14, with LTBI treatment provided in the United States; Strategy 2 offered pre-departure IGRA testing for both children and adults but held LTBI treatment until after arrival; Strategy 3 offered pre-departure IGRA testing for children and adults with LTBI treatment offered before departure and then re-offered in the United States to anyone who had not completed treatment. The model projected that any of these testing and treatment approaches would avert 32–60% of lifetime TB cases in children and adults compared with no IGRA testing or LTBI treatment. Strategy 3 delivered the largest health gains and did so with lower incremental costs compared to Strategies 1 and 2. Against a no-intervention scenario, Strategy 3’s incremental cost-effectiveness ratio was $45,000 per QALY gained for children and $21,111 per QALY gained for adults. The analysis was funded by the CDC.

The findings suggest that adding a pre-departure offer of IGRA testing and voluntary LTBI treatment for U.S.-bound refugees could improve both health outcomes and value for money when combined with existing services to diagnose and treat TB disease. By shifting some testing and treatment steps to the pre-departure period, more people may start and complete LTBI treatment, increasing prevention of TB disease among a population that otherwise faces barriers to care after arrival. The authors note that such programs should be feasible, respectful of individual choice, and designed to work with current medical screening systems. While the study is model-based rather than a clinical trial, it builds on prior analyses and pilot work and provides quantitative estimates—both health benefits and costs—that can inform public health decisions about whether to expand pre-departure TB prevention for refugees.