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

• TB incidence rates no longer significantly declining in migrants for latter half of 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 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. While Ireland is a low TB incidence country, with crude incidence rates (CIRs) in the Irish-born below 6 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 analysing 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 analysed 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 3,364 TB patients, 48% were among migrants. Compared to Irish-born, migrants with TB were younger, had higher odds of living with HIV (OR: 3.8, CI: 1.99 to 7.73), extra-pulmonary disease (OR: 3.14, CI: 2.09 to 4.79), infection with drug-resistant strains (OR: 2.30, CI: 1.37 to 4.01) and residence in congregate residential settings (OR: 2.00, CI: 1.34 to 3.05) with lower odds linkage to outbreaks (OR: OR: 0.16, CI:0.09 to 0.28). Recently arrived migrants with TB had higher proportions of international protection applicants and refugees, pulmonary disease and people living with HIV. Between 2011-2021, a significantly declining temporal trend was present for migrants (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.