Delta agent is a type of virus called hepatitis D that causes symptoms only in people who also have a hepatitis B infection.
Hepatitis D virus
Causes, incidence, and risk factors
Hepatitis D virus (HDV) is only found in people who carry the hepatitis B virus. HDV may make a recent (acute) hepatitis B infection or an existing long-term (chronic) hepatitis B liver disease worse. 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 5% 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 more severe.
Many of the medicines used to treat hepatitis B are not helpful for treating hepatitis D. See hepatitis B.
Persons with long-term HDV infection may receive a medicine called alpha interferon for up to 12 months. A liver transplant for end-stage chronic hepatitis B may be effective.
Persons with an acute HDV infection usually get better over 2 to 3 weeks. Liver enzyme levels return to normal within 16 weeks.
About 10% of those who are infected may develop long-term (chronic) liver inflammation (hepatitis).
Chronic active hepatitis
Calling your health care provider
Call for an appointment with your health care provider if you have symptoms of hepatitis B.
Prompt diagnosis and treatment of hepatitis B infection can help prevent hepatitis D.
Avoid intravenous drug abuse. If you use IV drugs, avoid sharing needles.
A vaccine is available to prevent hepatitis B. Adults who are at high risk for hepatitis B infection, and all children should consider getting this vaccine.
Perrillo R. Hepatitis B and D. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 9th ed. Philadelphia, Pa: Saunders Elsevier;2010:chap 78.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and George F. Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program, San Diego, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.