Risk of hepatitis B when migrating from low to high endemic areas.

UNLABELLED: Prevalence of hepatitis B virus (HBV) infections varies markedly with geography and is endemic in the Arctic. Travel and migration have increased markedly while the influence of migration to high endemic areas remains unknown. We surveyed subjects migrating from an area with a low prevalence of chronic HBV infection (Denmark, 0.01%) to an endemic HBV area (West- and East Greenland, 3% and 29%) in order to describe the prevalence of HBV exposure among migrants. We included 198 Caucasian Danes that had migrated to Greenland and repeated the cross-sectional investigation after 10 years. We performed thorough serological testing for HBV. None had ongoing HBV infection. Migrants to East Greenland were more frequently exposed to HBV than those in West Greenland (34.3% vs 10.3%; p < 0.01). This difference was reduced at 10-year follow-up (8.1% vs 5.7%; ns) and the overall number of participants with past HBV infection decreased over the 10-year period from 19.4% to 6.9% (p = 0.02). In conclusion, migration from very low prevalence to endemic HBV areas associated with a markedly increased risk of exposure to HBV. Lack of vaccination among migrants from Denmark to Greenland was frequent and it poses a continuing risk. All who migrate from low to high endemic HBV areas should be vaccinated.

ABBREVIATIONS: HBV: Hepatitis B virus; HBV-DNA: Hepatitis B virus deoxyribonucleic acid; HBsAg: Hepatitis B surface antigen; Anti-HBs: Antibodies against hepatitis B surface antigen; Anti-HBc: Antibodies against hepatitis B core antigen; BMI: Body mass index.