Post-migration follow-up programme for migrants at increased risk of developing tuberculosis: a cohort study.

Following pre-migration screening for tuberculosis (TB), migrants who are deemed to be at a high risk of developing TB must attend post-entry follow-up in Australia. We aimed to evaluate the effectiveness of post-migration TB follow-up in the state of New South Wales to diagnose TB in these high-risk migrants. In this retrospective cohort study, we assessed the risk of TB in migrants who arrived in New South Wales between 2000 and 2015 and were referred for post-migration follow-up. Clinical notes were examined for a nested cohort to determine whether TB was diagnosed via the follow-up programme or via passive case finding. Of the 32 550 migrants referred for follow-up, 428 (1.3%) developed TB. The incidence of TB was 436 per 100 000 person-years (95% CI 384-491 per 100 000 person-years) in the first 2 years after arrival and 128 per 100 000 person-years (95% CI 116-140 per 100 000 person-years) over the mean study observation period of 10.3 years. An estimated 63% of cases were diagnosed via follow-up. TB notifications occurred 0.55 years earlier since time of arrival in Australia in migrants who attended follow-up than in those who did not. Post-migration follow-up detected 63% of TB cases in high-risk migrants and potentially prevented delay of TB diagnosis.

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; I2=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; I2=99%). The pooled tuberculosis incidence from 15 cohorts was 1249 per 100 000 person-years of follow-up (95% CI 924-1574; I2=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. FUNDING: Australian National Health and Medical Research Council.