Active and latent tuberculosis among refugees and asylum seekers: a systematic review and meta-analysis

Background: In 2017, there were 68.5 million refugees, asylum seekers and persons displaced by wars and conflicts worldwide. Tuberculosis prevalence in the country of origin and adverse conditions endured during their journey may increase their risk for tuberculosis. Objective: We summarized the prevalence of active and latent tuberculosis infection among refugees and asylum seekers through a literature systematic review and meta-analysis by country of origin. Methods: Articles published in Medline, EMBASE, Web of Science and LILACS from 2000 to August 2017 were searched for, without language restriction. Two independent authors performed the study selection, data extraction and quality assessment. Random effect models were used to estimate pooled measures of active and latent tuberculosis prevalence. Sub-group analysis was performed according to country of origin and host continent. Results: Sixty-seven out of 767 identified papers were included, of which 16 entered the meta-analysis. Pooled prevalence of active and latent tuberculosis was 1% [95% confidence interval (CI)=1-2%] and 37% (95% CI=23-52%), respectively, both with high level of heterogeneity (I 2 =98.2% and 99.8%). Prevalence varied more according to countries of origin than host continent. Ninety-one per cent of studies reported routine screening of recently arrived immigrants in the host country; two-thirds confirmed tuberculosis bacteriologically. Many studies failed to provide relevant information. Conclusion: Tuberculosis is a major health problem among refugees and asylum seekers and should be given special attention in any host continent. To protect this vulnerable population, ensuring access to healthcare for early detection for prevention and treatment of the disease is essential. Key words: Forced migration. Mycobacterium Tuberculosis. Latent tuberculosis infection. Prevalence. Global health.