Delta agent (Hepatitis D)

Alternative names
Hepatitis D virus

Hepatitis D infection involves a defective viral agent that causes symptoms only in association with hepatitis B infection.

Causes, incidence, and risk factors

Hepatitis D virus may increase the severity of an acute hepatitis B infection, aggravate previously existing hepatitis B liver disease, or cause symptoms in previously asymptomatic hepatitis B carriers.

Hepatitis D infects about 15 million people worldwide, occuring in 5% of people with hepatitis B.

Risk factors include the following:

  • Previous hepatitis B infection  
  • Being a carrier of hepatitis B  
  • Receiving many blood transfusions  
  • Intravenous drug abuse


Hepatitis D may increase the severity of symptoms associated with all forms of hepatitis B.

Signs and tests

  • Liver enzymes are elevated.  
  • Anti-delta agent antibody is positive.  
  • Liver biopsy shows acute hepatitis.


Treatment is the same as for hepatitis B.

Expectations (prognosis)

Expectations are similar to those of acute hepatitis B. The acute illness usually subsides over 2 to 3 weeks, and the liver enzyme levels return to baseline within 16 weeks.

About 10% of people infected may develop chronic hepatitis.


  • Chronic active hepatitis  
  • Fulminant hepatitis

Calling your health care provider

Call for an appointment with your health care provider if symptoms of hepatitis B occur.


Prompt recognition and treatment of hepatitis B infection can help prevent hepatitis D.

Avoid intravenous drug abuse. If you use IV drugs, avoid sharing needles.

There is a vaccine available to prevent hepatitis B and should be considered by people who are at risk due to IV drug use, exposure to blood products, or sexual behaviors.

Johns Hopkins patient information

Last revised: December 5, 2012
by David A. Scott, M.D.

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.