Delta agent (Hepatitis D)
Hepatitis D is a viral infection caused by the hepatitis D virus (previously called the Delta agent). It causes symptoms only in people who also have hepatitis B infection.
Hepatitis D virus (HDV) is found only in people who carry the hepatitis B virus. 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:
- Abusing intravenous (IV) or injection drugs
- Being infected while pregnant (the mother can pass the virus to the baby)
- Carrying the hepatitis B virus
- Men having sexual intercourse with other men
- Receiving many blood transfusions
Hepatitis D may make the symptoms of hepatitis B worse.
Symptoms may include:
- Abdominal pain
- Dark-colored urine
- Joint pain
- Loss of appetite
Exams and Tests
You may need the following tests:
- Anti-hepatitis D antibody
- Liver biopsy
- Liver enzymes (blood test)
Many of the medicines used to treat hepatitis B are not helpful for treating hepatitis D.
You may receive a medicine called 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
When to Contact a Medical Professional
Contact your health care provider if you have symptoms of hepatitis B.
Steps to prevent the condition include:
- Detect and treat hepatitis B infection as soon as possible to help prevent hepatitis D.
- Avoid intravenous (IV) drug abuse. If you use IV 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.
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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.
Last reviewed on: 10/27/2020
Reviewed by: Michael M. Phillips, MD, Clinical Professor of Medicine, The George Washington University School of Medicine, Washington, DC. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.