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
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:
Hepatitis D may make the symptoms of hepatitis B more severe.
Symptoms may include:
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).
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.