Global Epidemiology of Hepatitis B Virus (HBV) Infection

Infection with hepatitis B virus (HBV) remains a top health priority worldwide and a devastating cause of morbidity andmortality accounting formore than 600,000 deaths in 2013. It is mainly transmitted through percutaneous or mucosal contact with infected blood or other body fluids. In high-endemic settings, the commonest route of transmission is from infected mothers to neonates, whereas in areas of low endemicity the infection ismostly acquired during adolescence and early adulthood through high-risk behaviors. More than 350 million are chronically infected with HBV, ranging from <0.5%in areas of low endemicity to above 8%in highly-endemic countries, with hyperendemic foci in South-East Asia andWestern Pacific Regions. Expansion of national immunization programs with >80 % coverage globally has resulted in a steady decline in the prevalence of HBV. However, there are remaining threats to the successful eradication of HBV worldwide. We review available data on global epidemiology of HBV infection, also focusing on transmission modes by region and specific preventative measures instituted.