Post-migration follow-up of migrants identified to be at increased risk of developing tuberculosis at pre-migration screening: a systematic review and meta-analysis

Background Post-migration follow-up of migrants considered at increased risk of developing tuberculosis based on pre-migration screening abnormalities (high-risk migrants) is implemented in several low-incidence countries. We aimed to determine the rate of tuberculosis in this population to inform cross-border tuberculosis control policies. Methods We searched MEDLINE and Embase (since inception to Jan 12, 2017) for studies evaluating post-migration follow-up of high-risk migrants. Outcomes evaluated were the number of tuberculosis cases occurring post-migration, expressed as the tuberculosis incidence per 100 000 person-years of follow-up, as cumulative incidence of tuberculosis per 100 000 persons, and the cumulative incidence of tuberculosis at the first post-migration follow-up visit. Random-effects models were used to summarise outcomes across studies. Findings We identified 20 publications (describing 23 study cohorts) reporting the pre-migration screening outcomes of 8 355 030 migrants processed between Jan 1, 1981, and May 1, 2014, with 222 375 high-risk migrants identified. The pooled cumulative incidence of tuberculosis post-migration in our study population from 22 cohorts was 2794 per 100 000 persons (95% CI 2179-3409; I-2 = 99%). The pooled cumulative incidence of tuberculosis at the first follow-up visit from ten cohorts was 3284 per 100 000 persons (95% CI 2173-4395; I-2 = 99%). The pooled tuberculosis incidence from 15 cohorts was 1249 per 100 000 person-years of follow-up (95% CI 924-1574; I-2 = 98%). Interpretation The high rate of tuberculosis in high-risk migrants suggests that tuberculosis control measures in this population, including more sensitive pre-migration screening, preventive treatment of latent tuberculosis infection, or post-migration follow-up, are potentially effective cross-border tuberculosis control strategies in low-incidence countries.