The impact of migration on tuberculosis epidemiology and control in high-income countries: a review

Abstract

Tuberculosis (TB) causes significant morbidity and mortality in high-income countries with foreign-born individuals bearing a disproportionate burden of the overall TB case burden in these countries. In this review of tuberculosis and migration we discuss the impact of migration on the epidemiology of TB in low burden countries, describe the various screening strategies to address this issue, review the yield and cost-effectiveness of these programs and describe the gaps in knowledge as well as possible future solutions.The reasons for the TB burden in the migrant population are likely to be the reactivation of remotely-acquired latent tuberculosis infection (LTBI) following migration from low/intermediate-income high TB burden settings to high-income, low TB burden countries.TB control in high-income countries has historically focused on the early identification and treatment of active TB with accompanying contact-tracing. In the face of the TB case-load in migrant populations, however, there is ongoing discussion about how best to identify TB in migrant populations. In general, countries have generally focused on two methods: identification of active TB (either at/post-arrival or increasingly pre-arrival in countries of origin) and secondly, conditionally supported by WHO guidance, through identifying LTBI in migrants from high TB burden countries. Although health-economic analyses have shown that TB control in high income settings would benefit from providing targeted LTBI screening and treatment to certain migrants from high TB burden countries, implementation issues and barriers such as sub-optimal treatment completion will need to be addressed to ensure program efficacy.

The Impact of Tuberculosis among Immigrants: Epidemiology and Strategies of Control in High-Income Countries—Current Data and Literature Review

“…The screening may decrease the period of infectiousness by as much as 33% in some situations [5]. LTBI screening is effective in persons at risk of contracting M. tuberculosis or of progressing from LTBI to active TB.…”

“…Literature shows that 88% of countries use chest X-rays (CXR) alone or in combination with clinical examination or TST [5,24]. The sensitivity and specificity of CXR vary from 86-97% to 75-89%, respectively, and according to the criteria of imaging interpretation.…”

“…Overview and epidemiological features of TB among immigrants in low-TB burden countries 1 Many 1 migrants originating from countries where TB has a high incidence, including tropical areas [9], have a high risk of acquiring TB before migration. Much of TB burden is concentrated in high-burden settings of Africa and Asia (28 and 58%, respectively) where TB continues to be a cause of morbidity and mortality [5]. Some areas of tropical countries, such as Haiti, Perù, Bolivia, and Suriname, have the highest TB incidence in the Americas (between 100 and 200 per 100,000 inhabitants) [10], whereas Brazil has a high TB burden, but this is not uniformly distributed.…”

“…Although the general decrease [1, 4] of TB cases (globally, the TB mortality rate fell by an estimated 45% between 1990 and 2013 and the TB prevalence rate fell by 41% during the same period) in recent decades has led the medical profession to pay less attention to the presence of high-risk patients, TB continues to be a public health concern in high-income countries, primarily among the foreign-born and migrant population [5]. In fact, a reappearance of this disease was observed since the early 1990s due to other than the spread of HIV infection and the increase in poor living conditions and immunosuppression; it is due to the migratory phenomenon, and an interplay of various push and pull factors are a consequence of wealth disparity, poverty, wars, and political persecutions [6,7].…”

Communicable Diseases Among Refugees with a Focus on the Middle East

“…One particularly famous example is the re-emergence of tuberculosis (TB) in Europe. While once considered a disease of the past, new cases of TB in Europe and the West are frequently attributed to the migration of people from endemic countries, such as Africa and India [7]. In some refugee settings, women and children are believed to comprise about 80% of the population, and they are the most vulnerable to the consequences of displacement, including rape, infectious diseases, and, in particular, sexually transmitted infections (STIs) [8].…”