Hepatitis D Virus Infection

Hepatitis D virus (HDV), also known as hepatitis delta virus, is a defective, hepatotropic pathogenic agent. The life cycle of HDV requires the hepatitis B surface antigen (HBsAg) provided by hepatitis B virus (HBV).¹ Like HBV, HDV is transmitted by the parenteral route through infectious body fluids; intravenous drug users are at highest risk for infection because of contaminated syringes.^2,3 Key features of the infection are its unique biologic characteristics and ominous medical effect. Clinical studies have shown that chronic hepatitis D is the most severe and progressive form of viral hepatitis in humans.² The infection is ubiquitous, yet 40 years after it was identified, the prevalence remains undetermined in many parts of the world. In three recent meta-analyses, the number of HDV-infected persons worldwide ranged from 12 million to 72 million, underscoring the heterogeneity of current epidemiologic data.³ Valid therapies to cure hepatitis D are an urgent need, and new therapeutic strategies are in development.