Evaluation of the post-landing surveillance process for people migrating to British Columbia: A retrospective cohort study.

Objectives: People migrating to Canada are disproportionately impacted by tuberculosis (TB) disease. Prior to arrival, Immigration, Refugees and Citizenship Canada (IRCC) require an immigration medical exam (IME) intended to detect TB disease in all permanent and select temporary residents. People deemed high risk for TB are then referred for post-landing surveillance. This process has not substantially changed in four decades, prompting our review.

Methods: We performed a retrospective cohort study of people referred for post-landing surveillance in British Columbia (BC) from Aug 1, 2020, to May 31, 2022. Through chart review, clinical and demographic data were recorded from the IME and provincial TB registry. Participants were followed for 2 years to assess for TB disease and to record their clinical outcomes.

Results: Of 1700 participants, 19 (1.1%, 95% CI 0.7, 1.7) were diagnosed with TB disease after arriving in Canada; 580 (34.1%) had prior TB treatment noted on their IME, with a median time from treatment to arrival of 9 years (IQR 4-18 years). The post-landing process took a median of 211 days (IQR 160-282 days) to complete workup. Some participants (611; 35.9%) received either an interferon gamma release assay or tuberculin skin test with 127 (35.5%) and 166 (65.6%) positive results, respectively.

Conclusion: The post-landing surveillance process in BC is slow and resource-intensive for both migrants and the healthcare system, with uncertain impact on outcomes. These findings highlight existing inefficiencies in the process and the need to identify people who are at highest risk.