Hepatitis D, also known as “Delta Hepatitis,” is an infection of the liver caused by the hepatitis D virus (HDV) that causes liver inflammation and damage. Hepatitis D can only occur in individuals who are already infected with the hepatitis B virus (HBV). Hepatitis D can be acute (short-term) or become a chronic (long-term) infection. Co-infection with both the hepatitis B virus and the hepatitis D virus (superinfection) is the most severe form of chronic hepatitis and can rapidly lead to the development of hepatocellular carcinoma (liver cancer; HCC) or death. Hepatitis D is transmitted by blood or body fluids through sexual contact, the shared use of contaminated needles, or infected blood transfusions.

Symptoms of an acute hepatitis D infection may include weakness, fatigue, lack of appetite, nausea and vomiting, right upper abdominal pain over the liver, dark urine, pale stool, and jaundice (yellowing of eyes and skin). Individuals with a chronic hepatitis D infection may have little or no symptoms for years until developing cirrhosis (scarring liver disease) when they may experience weakness, fatigue, weight loss, abdominal swelling, ankle swelling (edema), itching, and jaundice. Chronic hepatitis D infection may cause severe complications, such hepatocellular carcinoma (liver cancer) and death.

There is currently no treatment for acute hepatitis D infection. Chronic hepatitis D infection may be treated with pegylated interferon alpha for at least 48 weeks or antiviral drugs, such as entecavir. Hepatitis D infection can be prevented with the hepatitis B vaccine.