Hepatitis D virus (HDV) is found only in people who carry the hepatitis B virus. It can occur with a new infection of hepatitis B (coinfection) or on top of a hepatitis B infection (superinfection). HDV may make liver disease worse in people who have either recent (acute) or long-term (chronic) hepatitis B. It can even cause symptoms in people who carry hepatitis B virus, but who never had symptoms.

Hepatitis D infects about 15 million people worldwide. It occurs in a small number of people who carry hepatitis B.

Risk factors include:

• Being infected while pregnant (the mother can pass the virus to the baby).
• Carrying the hepatitis B virus.
• Being in a high-risk group for getting hepatitis B or D. Examples include sharing body fluids such as through sexual contact, household blood or saliva contact, or sharing needles/drug equipment. 
• Receiving many blood transfusions. The US blood supply is screened for hepatitis virus, so this is uncommon.
• Using intravenous (IV) or injection drugs.
• Rarely, a baby can get hepatitis D from a mother with hepatitis D.

Hepatitis D may make the symptoms of hepatitis B worse.

Symptoms may include:

• Abdominal pain
• Dark-colored urine
• Fatigue
• Jaundice
• Joint pain
• Loss of appetite
• Nausea
• Vomiting

You may need the following tests:

• Anti-hepatitis D antibody. Blood tests for hepatitis B will also be done. 
• Liver biopsy is occasionally done.
• Liver enzymes (blood test) and other bloodwork to check for other liver diseases and see how damaged the liver is.
• Imaging tests such as an abdominal ultrasound or a special ultrasound called elastography, to look at the liver and see how damaged it is.
• Evaluation for liver cancer.

Many of the medicines used to treat hepatitis B are not helpful for treating hepatitis D.

You may receive a once weekly injectable medicine called pegylated alpha interferon for up to 12 months if you have a long-term HDV infection. A liver transplant for end-stage chronic hepatitis B may be effective.

People with an acute HDV infection most often get better over 2 to 3 weeks. Liver enzyme levels return to normal within 16 weeks.

About 1 in 10 of those who are infected may develop long-term (chronic) liver inflammation (hepatitis).

Complications may include:

• Chronic active hepatitis
• Acute liver failure

Contact your health care provider if you have symptoms of hepatitis D.

Steps to prevent the condition include:

• Detect and treat hepatitis B infection as soon as possible to help prevent hepatitis D.
• Avoid intravenous (IV) or injection drug use. If you inject drugs, avoid sharing needles.
• Get vaccinated against hepatitis B.

Adults who are at high risk for hepatitis B infection and all children should get this vaccine. If you do not get Hepatitis B, you cannot get Hepatitis D.

Delta agent

Ghany MG. Hepatitis D. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 81.

Murray PR, Rosenthal KS, Pfaller MA. Hepatitis viruses. In: Murray PR, Rosenthal KS, Pfaller MA, eds. Medical Microbiology. 9th ed. Philadelphia, PA: Elsevier; 2021:chap 55.

Thio CL, Hawkins C. Hepatitis delta virus. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 146.

Updated by: Jenifer K. Lehrer, MD, Gastroenterologist, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.