Effects of migration on tuberculosis epidemiological indicators in low and medium tuberculosis incidence countries: A systematic review

Sarah Jackson,Zubair Kabir,Catherine Comiskey

doi:10.1016/j.jctube.2021.100225

Abstract

BackgroundTuberculosis (TB) remains one of the top ten causes of death each year globally. While the risk of migrant TB is linked to the TB incidence in their country of origin, the migration process can increase the TB risk. ObjectiveWe aimed to synthesis the evidence on key differences in the epidemiological profile of TB between migrants from high TB incidence birth countries and non-migrants resident in low to medium incidence TB countries. MethodsWe conducted a systematic review where the population was all active TB cases in countries with low to medium TB incidence (<40/100,000 population), the exposure was migration to a low or medium TB incidence country and the comparator was non-migrant TB cases in low or medium incidence countries. Overall proportions were compared between migrants and non-migrants, using Fisher’s exact test. Meta-analysis of proportions was carried out for the primary outcome (active TB) while meta-analyses of odds ratios (ORs) were performed using a random effects model for secondary outcomes; sputum-smear positivity, any first line drug resistance, multi-drug resistance (MDR), clustered cases, HIV coinfections and successful treatment. Heterogeneity was evaluated and sources were investigated using subgroup and sensitivity analysis. ResultsSignificant differences were found in the overall proportions of high TB incidence migrants and non-migrants for MDR cases, clustered cases, HIV coinfections and successful treatment, as well as a significant difference in the OR among MDR cases (3.91). ConclusionThis review has demonstrated significant differences in key epidemiological indicators between high TB incidence migrants and non-migrants, indicating policy implications.

Highlights

Tuberculosis (TB) continues to kill more people annually than any other infectious disease and is one of the top ten causes of death each year globally
The review adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) and Meta-analysis of Observa tional Studies in Epidemiology (MOOSE) guidelines. [12,13] The pro tocol was prospectively registered on the International Prospective Register of Systematic Reviews (PROSPERO) as CRD42018095038.[14]
While significant differences in overall proportions among high incidence migrants and non-migrants were observed in key epidemio logical indicators; multi-drug resistance (MDR)-TB, HIV co-infected cases, clustered cases and successfully treated cases, the results of the meta-analyses only sup ported this finding for MDR-TB

Summary

Introduction

Tuberculosis (TB) continues to kill more people annually than any other infectious disease and is one of the top ten causes of death each year globally. As noted by Hanway et al, the category of “foreign-born” essentially refers to being born in any one of 197 potential other countries.[9] Migrants are a highly diverse group in most countries, manifesting through their country of origin, mode of migration, socioeconomic grouping, demographic profile and health status. This leads to differing chances of importing existing infection, acquiring infection once arrived and accessing health services if they develop TB. Conclusion: This review has demonstrated significant differences in key epidemiological indicators between high TB incidence migrants and non-migrants, indicating policy implications

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Discussion

Conclusion