Epidemiology of the Hepatitis D virus

Hepatitis D is a globally occurring liver disease. It afflicts those who have been infected by both the Hepatitis B virus (HBV) and also the Hepatitis D virus (HDV), since HDV needs the hepatitis B surface antigen (HBsAg) to replicate. It is therefore most prevalent in countries where HBV infection is also common, currently the Amazon basin and low income regions of Asia and Africa. Improved measures to control HBV in industrialised countries (such as by vaccination) have also reduced the prevalence of HDV, with the main remaining at-risk populations in those countries being injection drug users and immigrants from endemic HDV areas.