HDV infection is seen mainly in Central Africa, the Middle East and central South America.
Low rates of infection are present in most of Europe, the United States, and Australia. In the U.S. HDV is confined to people who are exposed to blood or blood products such as medical personnel, drug addicts and hemophiliacs. While the likelihood of developing chronic HBV infection usually decreases in the presence of HDV superinfections, most patients will develop chronic HDV infections which produce more frequent and more severe liver disease and cirrhosis than does chronic HBV infection alone. HDV is spread through anyone coming into contact with infected blood, contaminated needles or having sexual contact with an HDV infected person. They are similar to those for HBV hepatitis.