Tuberculosis in migrants in low-incidence countries: epidemiology and intervention entry points

Abstract

As tuberculosis (TB) rates continue to decline in native populations in most low TB incidence countries, the proportion of TB patients born outside their country of residence ('foreign-born') increases. Some low-incidence countries have experienced a substantial increase in TB rates related to recent increases in the number of asylum seekers and other migrants from TB-endemic countries. However, average TB rates among the foreign-born in low-incidence countries declined moderately in 2009-2015. TB in foreign-born individuals is commonly the result of reactivation of latent infection with Mycobacterium tuberculosis acquired outside the host country. Transmission is generally low in low-incidence countries, and transmission from migrants to the native population is often modest. Variations in levels and trends in TB notifications among the foreign-born are likely explained by differences and fluctuations in the number and profile of migrants, as well as by variations in TB control, health and social policies in the host countries. To optimise TB care and prevention in migrants from endemic to low-incidence countries, we propose a framework for identifying possible TB care and prevention interventions before, during and after migration. Universal access to high-quality care along the entire migration pathway is critical. Screening for active TB and latent tuberculous infection should be tailored to the TB epidemiology, adapted to the needs of specific migrant groups and linked to treatment. Ultimately, the long-term TB elimination goal can be reached only if global health and socio-economic inequalities are dramatically reduced. Low-incidence countries, most of which are among the wealthiest nations, need to contribute through international assistance.

Haemoptysis and fever in a young refugee from Somalia

“…This is a representative case of tuberculosis (TB) diagnosed in a low TB incidence country during a time period of intensified migration flow from Africa to Europe. In recent years, TB in migrants has represented a major public health challenge for low TB incidence countries such as Italy (Lönnroth et al, 2017;Sotgiu et al, 2017a). Incidence rates in foreign-born populations coming from high TB burden areas (e.g., Somalia) are higher than those recorded in the native European population; furthermore, migrants show a higher probability of developing the disease from latent TB infection acquired in the country of origin or on the route to Europe (Sotgiu et al, 2017a;Walker et al, 2018).…”

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

“…Symptoms of the active phase of tuberculosis, such as coughing and fatigue, may go unnoticed to already infected individuals and health care workers in crisis settings, because they are insidious (17). Dangerous situations encountered during migration, including overcrowding, incarceration, malnutrition, challenges to access health care, low adherence to treatment, associated risk of HIV infection and exposure to other migrants from higher incidence countries also contribute to the risk of contamination by M. tuberculosis and progression to disease (8,(64)(65)(66).…”

Tuberculosis-Related Hospitalizations in a Low-Incidence Country: A Retrospective Analysis in Two Italian Infectious Diseases Wards

“…The higher TB incidence in foreign-born persons living in low-incidence countries is associated with the high TB incidence in their country of origin, more often following reactivation of a latent TB infection owing to poor living conditions in the host country. Moreover, the increased risk of Mycobacterium tuberculosis infection can be associated with travels to the native country, involving new generations of foreign-born families [5]. Cowger and colleagues showed that having at least one parent born outside of the USA increased the likelihood of developing TB by 3.5 times, while having two parents born outside of the USA increased the risk up to 8.5 times [4].…”