Migrants and hepatitis: A tale of two worlds.

Migrants from some areas of the world bear a high burden of hepatitis C virus (HCV) chronic infection and may represent a major proportion of chronic HCV carriers in countries where the background infection rate is otherwise low. In this issue of the Journal of Viral Hepatitis, Passos-Castilho et al. focus on the rates and trends of reported HCV diagnoses over 20 years in Quebec, Canada. In this country, migrants account for 35% of HCV infections, despite representing only 22% of the population.1 Passos-Castilho and colleagues aimed to investigate sub-groups of migrants, defined as persons born outside of Canada with permission to live permanently in Canada, who displayed the highest HCV infection rates and changes over time. The median time frame leading up to diagnosis after arrival in Quebec was 7.5 years and remained unchanged over the study period, demonstrating a persistent gap in delayed diagnosis. The slowest decline in HCV rates was observed among migrants compared with natives in Canada, highlighting a need for targeted screening particularly when arriving from sub-Saharan Africa, Asia and middle-income Europe.1 Though migration status is not by itself an indicator of an increased likelihood of HCV or hepatitis B virus (HBV) chronic infection, the rate of chronic HCV or HBV carriage in the country of origin may serve as a proxy for the prevalence in migrants upon arrival in a new country.2 The largest number of international migrants resided in Europe in 2020, with a total of 87 million. An estimated 30 million new migrants born outside the European Continental Region arrived from Asia, Africa and the Middle East in Europe between 2000 and 2020.3 The prevalence of HCV and HBV infection in migrants from these regions to high-income European countries was mostly comparable or lower to those reported for their country or region of origin.4 Nonetheless, in absolute terms, the prevalence in many migrant groups is remarkably higher than the prevalence in the general population of most high-income European countries. The rate of HBV infection among migrants to European Union (EU) countries born in highly endemic regions was reported as 6%, compared to 1% in the general population.4 Regarding HCV infection, migrants account for a large proportion of HCV cases in the EU/EEA (on average 14% of cases and >50% of cases in some countries).4 Data from 50 studies reporting on 38,635 migrants from all world regions show an overall seroprevalence of HCV of 1.9% (95% CI: 1.4–2.7, I2 96.1). Older age and region of origin, particularly sub-Saharan Africa, Asia and Eastern Europe were the strongest predictors of HCV infection. The estimated HCV prevalence among migrants from the above regions was >2%, which was higher than that reported for most host populations.5 Similarly, in the European Economic Area (EEA), which hosts an estimated 4.2 million adults with chronic HCV infection, the prevalence of anti-HCV antibodies was reported as 2% in migrants from endemic countries and as 1% in the general population.2, 6 Migrants permanently living in the European region are older and more likely to have advanced liver disease and hepatocellular carcinoma compared with non-migrants at the time of HCV diagnosis.7 This also holds true for HBV infection and is likely due to missed or delayed diagnoses and possibly to infection at an earlier age, as demonstrated by the study of Passos-Castilho and other studies.1, 5 Few European countries have national guidance on testing migrants for HCV. Only 15 policies and guidelines on TB, HIV and viral hepatitis services for refugees and migrants can be identified in the 53 member states of the WHO European region.8 Approaches to screening vary considerably in the WHO European region, with no agreement on the most effective and cost-effective approaches to targeted interventions for migrants or on which have the best uptake and treatment outcomes.9, 10 This lack of consensus contributes to heterogeneity across the Region of policies for the screening of migrants with infectious diseases.8 The recommendation strength for HCV screening among migrants is conditional to the prevalence of hepatitis C in the migrant's country of origin.11 Migrants from intermediate and high-endemicity countries (= >2% for HBsAg and = >1% for anti-HCV), both from within or outside the EU/EEA, are recognised as a key population for hepatitis B and C prevention and care. Since 2015, the arrival of an unprecedented number of refugees and migrants has led to a migration and humanitarian crisis in the EU. The migrant population in the European region is highly heterogeneous, not only in terms of geographical origin; it includes economic migrants, refugees, asylum seekers and undocumented persons. Even though, a legal difference is only acknowledged between ‘refugee’ and ‘migrant’, from the healthcare coverage perspective, it is of paramount importance to distinguish irregular migrants and short-term or temporary migration from long-term or permanent migration.12 Irregular immigration is a top priority in the European Union.13 About 1.08 million non-EU citizens were found to be illegally present in the EU in 2022, which is an increase of 59% since 2021; with young men aged between 18 and 34 years who accounted for almost half of that percentage.14 In 2022, 881,220 first-time asylum seekers applied for international protection in the EU, with an increase of 64% compared to 2021. Almost 80% of asylum seekers was under 35 years of age.15 In 2021, the median age of new immigrants in Europe was 30 years,12 an overall scenario which is, thus vastly different from that assessed in the Canadian study of Passos-Castilho, where immigrants were older with a mean age of 47.7 years. The prevalence of HBV in refugees and asylum seekers in EU countries is up by 10%, whereas HCV prevalence in new immigrants to the EU seems to be lower than in the country of origin.6, 11, 16-20 However, few studies have focused on the most vulnerable groups such as asylum seekers, refugees and undocumented migrants to allow for an accurate assessment of HCV infection rates in different subgroups of new migrants. While the HBV carriage rate reflects a lack of immunisation policies at birth or during childhood in endemic countries, hepatitis C in migrants, if not drug users, is often contracted later in life, mostly through exposure in healthcare settings with poor infection control practices. Migration to a low endemic country at a tender age could explain the lower prevalence among migrants compared to the prevalence in the country of origin. A Lancet commission study observed that migrants arriving in Europe often had better health than people who remained in their countries of origin—known as the ‘healthy migrant concept’. On the other hand, the study recognised that some subgroups from specific geographical locations, potentially vulnerable to infectious liver diseases in their home nations or during their journeys, were more likely to have or be at risk of contracting these diseases.21 Infections do not arise because a specific group of the population have been exposed to an infectious agent, but because it is subject to multiple determinants that collectively create the conditions in which the population is more likely to be infected and less likely to be able to cope with infections.22 Migrant infection burden is due to a combination of vulnerability factors as well as social and economic vulnerability in host countries including exposure to infections, inadequate healthcare access and poor living conditions.6 In 2018, a position statement by the European Association for the Study of the Liver on immigration and viral hepatitis recommended early targeted screening programs for migrants, ideally at the port of arrival, to ensure quick access to treatment.23 The focus of migrant screening for infectious diseases has now shifted to a variety of initiatives including pre-entry screening, community-based case detection and vaccine catch-up approaches in countries of settlement.24, 25 An example of this is the HIV, HBV and HCV screening program in Sicily (southern Italy), that provided not only tested undocumented immigrants, but also offered treatment and linkage to care, clearly demonstrating the feasibility of retaining migrant patients throughout the testing and treatment process.16 A successful micro-elimination strategy targeting migrants from high-prevalence countries must include provisions for screening and linkage to care, as well as cultural mediators for translation and clarification concerning the importance of screening and treatment.26 After arrival at their point of entry, migrants often continue their journey to other countries. Many European countries have guidelines on infection testing and vaccination, even though they have a limited focus on migrants and a clear disconnection between the recommendations and actual clinical implementation.25 European countries vary greatly in the amount and type of healthcare to which migrants are legally entitled, particularly if undocumented. The extent to which migrants are integrated into national health and welfare systems differs between European countries. Despite being included under universal health coverage, with commitments for United Nations member states to provide access to health coverage for refugees and migrants, these persons often have problems in accessing and obtaining healthcare.27 In some countries, there are restrictions on the provision of healthcare to undocumented migrants and those without insurance, and the countries that do provide healthcare often limit it to emergency care rather than ongoing, community-based, preventive measures such as infection screening and vaccination, or restrict availability of services creating barriers to access.28 While patients with viremic HCV infection are eligible for antiviral treatment, patients with chronic HBV infection and those coinfected with HDV infection need linkage to care to evaluate their eligibility for treatment and the actual feasibility of long-term or lifelong treatments. Even after linkage to tertiary care has been successfully achieved, simple factors such as language may deter them from attending follow-ups.29 Addressing language and cultural barriers is required to screen and treat migrants. The acceptability of screening and treatment is highly dependent on unawareness of entitlements, cultural sensitivity, health literacy and lack of knowledge and information pertinent to infection screening and vaccination. Stigma and fear of disclosure, competing non-health concerns including employment, housing and legal status, lack of stability, the complexity of personal and social circumstances, disparities in access to preventive healthcare and possible comorbidities, in addition to the complexity of current models of care present barriers to all migrant groups. Furthermore, undocumented migrants and asylum seekers face further obstacles: they may be excluded from the general healthcare system due to hostile laws implemented by host nations, administrative requirements (e.g. proof of lack of financial means; requirement to register with a general practitioner), the fear that visits to healthcare services may be reported to immigration law enforcement authorities or because sociocultural factors deter them from accessing care.30 Improving screening, diagnosis and the care continuum for HCV and HBV infection in migrants is key element to achieving viral hepatitis elimination. A global health holistic and inclusive approach to migrant health need to be adopted across the EU/EEA, integrating their needs within each country's healthcare system with specific strategies suitable for improving engagement according to their sociocultural needs removing legal, social and cultural barriers to health services. None of the authors have a conflict of interest to disclose. Data sharing not applicable to this article as no datasets were generated or analysed during the current study.