In the United States HDV affects approximately 5% of patients (less than 200,000 patients) co-infected with the hepatitis B virus. While uncommon in the United States, HDV co-infection is more common in parts of the world such as China, Russia, Middle East, Mongolia, Romania, Georgia, Turkey, Pakistan, Africa, and the Amazonian river basin. Globally HDV is estimated to affect 15-20 million people.

The hepatitis delta virus is transmitted the same way as the hepatitis B virus - through exposure to infected blood or body fluids. 

High-Risk Groups for Hepatitis D:

  • Intravenous drug users¬†
  • Men who have sex with men
  • People with many sexual partners
  • People emigrating from countries where hepatitis D is common

HDV transmission is rare among those who receive blood transfusions or hemodialysis in the U.S. because blood products are routinely screened. In developing countries, screening of blood products is not common, so transfusions and hemodialysis can be a high-risk route of transmission.

Unlike hepatitis B infections, mother-to-child transmission of HDV is rare.