Hepatitis D virus is found worldwide, but with varying prevalence. HDV infection is endemic in parts of Central Africa, South America, Asia and the Mediterranean Basin. In the United States and Western Europe, infection with HDV occurs relatively infrequently, except in individuals exposed to blood or blood products (ie. IV drug users and hemophiliacs).
The pattern of HDV infection around the world is relatively consistent with the prevalence of chronic HBV infection. However, in most of Southeast Asia and China where chronic HBV infection is widespread, HDV infection is uncommon.
Individuals at high risk for contracting HDV include children and adults infected with HDV, IV drug users, hemodialysis patients, and those practicing risky sexual behavior. Vertical transmission from mother to child is relatively rare.
Worldwide, more than 15 million people are infected with HDV.
FIGURE from Fields Virology, 5th ed, 3037. The worldwide distribution of hepatitis delta virus (HDV) infection as measured by the prevalence of anti-HD in hepatitis B surface antigens (HBsAg)-positive individuals with acute or chronic hepatitis.