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

Abstract

Background: In 2018, there were 70.8 million refugees, asylum seekers and persons displaced by wars and conflicts worldwide. Many of these individuals face a high risk for tuberculosis in their country of origin, which may be accentuated by adverse conditions endured during their journey. We summarised the prevalence of active and latent tuberculosis infection in refugees and asylum seekers through a systematic literature review and metaanalyses by country of origin and host continent. Methods: Articles published in Medline, EMBASE, Web of Science and LILACS from January 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 average measures of active and latent tuberculosis prevalence. Subgroup meta-analyses were performed according to country of origin and host continent. Results: Sixty-seven out of 767 identified articles were included, of which 16 entered the meta-analyses. Average prevalence of active and latent tuberculosis was 1331 per 100 thousand inhabitants [95% confidence interval (CI) = 542-2384] and 37% (95% CI = 23-52%), respectively, both with high level of heterogeneity (variation in estimative attributable to 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.

Factors associated with latent tuberculosis among international migrants in Brazil: a cross-sectional study (2020)

“…The results show high prevalence of LTBI (TST ≥ 5 mm) in international migrants in Brazil, i.e., approximately 30% overall, or 23.5% in Boa Vista, 28.1% in Curitiba, 46.1% in Manaus, and 33.8% in São Paulo. A recent meta-analysis with studies published from January 2000 to August 2017 found 37% prevalence of LTBI among refugees and asylum-seekers, varying according to country of origin and continent of destination, and 28% among those who migrated to the Americas [ 9 ]. Although the search in the meta-analysis included the recent period of migratory crisis, no study was observed with migrants from the Americas, especially Latin America and specifically the Venezuelan population.…”

“…However, in Latin America, including Brazil, few studies have focused on TB in migrants, despite the issue’s relevance for the policy to eliminate TB. A systematic review with meta-analysis found higher prevalence of LTBI among migrants in Europe than in Latin America, [ 9 ] perhaps because screening of LTBI in migrants in Latin America is still incipient. This calls for investigation, especially in the capital cities.…”

The Strange Case of BCG and COVID-19: The Verdict Is Still up in the Air

“…Understanding these critical confounding factors is vital to delineate the contribution of BCG-induced immune protection against COVID-19. Effect of immigrant population with childhood BCG vaccination: Some high-income countries, such as the USA, have a significant immigrant population who would have received a childhood BCG vaccination in their country of birth [ 45 , 46 ]. The proportion of such a population would affect the disease transmission and mortality of COVID-19.…”

Introduction of short course treatment for latent tuberculosis infection at a primary care facility for refugees in Winnipeg, Canada: A mixed methods evaluation

“…As seen in other high-income countries, TB disease (TBD) burden in Canada's overall population is low (4.7 per 100,000 in 2020), while specific subpopulations experience disproportionately high rates ( 3 , 4 ). Among these groups are refugees and newcomers who have recently migrated from countries with high TB incidence ( 1 , 5 , 6 ). In 2019, TB among foreign-born persons accounted for 74.2% of reported cases (incidence rate of 15.8 per 100,000 population) in Canada ( 4 ), with the absolute number of foreign-born persons diagnosed with TBD continuing to steadily increase, despite the incidence rate staying relatively stable since 2007 ( 1 ).…”