# Differences found in patient profiles and incidence trends between migrants and native-born tuberculosis patients in Ireland: A cross-sectional analysis of national surveillance data, 2011-2021

## TL;DR

This study finds that TB incidence in migrants in Ireland is no longer declining as quickly as in native-born people, with migrants showing higher rates of drug resistance and HIV co-infection.

## Contribution

The study identifies key epidemiological differences between migrant and native-born TB patients in Ireland using national surveillance data from 2011-2021.

## Key findings

- Migrants with TB had higher odds of drug resistance and living with HIV compared to Irish-born cases.
- TB incidence rates in migrants no longer significantly declined in the latter half of the study period.
- Migrants were less likely to have pulmonary TB and be linked to outbreaks.

## Abstract

•Tuberculosis (TB) incidence rates no longer significantly declining in migrants for the latter half of the study period.•Key epidemiological differences were found between migrants and Irish-born cases.•Migrants with TB were less likely to have pulmonary TB and be linked to outbreaks.•Migrants had higher odds of drug resistance and living with HIV than Irish cases.•Recently arrived migrants had a higher level of pulmonary disease and living with HIV.

Tuberculosis (TB) incidence rates no longer significantly declining in migrants for the latter half of the study period.

Key epidemiological differences were found between migrants and Irish-born cases.

Migrants with TB were less likely to have pulmonary TB and be linked to outbreaks.

Migrants had higher odds of drug resistance and living with HIV than Irish cases.

Recently arrived migrants had a higher level of pulmonary disease and living with HIV.

Tuberculosis (TB) remains a global public health threat that was responsible for 1.3 million deaths in 2022 alone. Although Ireland is a low TB incidence country, with crude incidence rates (CIRs) in the Irish-born below six per 100,000 population since 2011, CIRs in the foreign-born population are up to 13 times higher. This study aims to inform TB prevention and care by analyzing the differences in the epidemiology of TB in native-born and foreign-born populations in Ireland.

A cross-sectional analysis of all TB notifications reported to the Irish TB Surveillance System from 2011-2021 was performed. Temporal trends in CIRs were analyzed using negative-binomial regression. Independent variables selected with a P-value of <0.25 in univariable analysis were investigated in a multivariable logistic regression model comparing TB patient characteristics between migrants and Irish-born.

Of the 3364 TB patients, 48% were among migrants. Compared with Irish-born, migrants with TB were younger, had higher odds of living with HIV (odds ratio [OR] 3.8, confidence interval [CI] 1.99-7.73), extrapulmonary disease (OR 3.14, CI 2.09-4.79), infection with drug-resistant strains (OR 2.30, CI 1.37-4.01), and residence in congregate residential settings (OR 2.00, CI 1.34-3.05) with lower odds linkage to outbreaks (OR 0.16, CI 0.09-0.28). Recently arrived migrants with TB had higher proportions of international protection applicants and refugees, pulmonary disease, and people living with HIV. Between 2011 and 2021, a significantly declining temporal trend was present for migrants (incidence rate ratio [IRR] 0.96, CI 0.95-0.98), Irish-born (IRR 0.89; CI 0.86-0.92), and total TB patients (IRR 0.95, CI 0.94-0.96). Between 2017 and 2021, a significantly declining temporal trend was still present in Irish-born (IRR 0.76, CI 0.69-0.83) and total patients (IRR 0.91, CI 0.88-0.95), but the trend was no longer significant among migrants with TB (IRR 0.96, CI 0.91-1.01).

A heightened awareness of extrapulmonary TB within health systems is needed, given the high levels observed among migrants with TB. The pace of TB decline among migrants is no longer significantly declining in the final years of this study period, making TB elimination targets more difficult to achieve. Differences in the epidemiology of TB reported by this study can be used to inform and enhance future TB service provision and promote migrant health.

Image, graphical abstract