Delta agent (Hepatitis D)

Definition

Delta agent is a type of virus called hepatitis D that causes symptoms only in people who have a hepatitis B infection.

Alternative Names

Hepatitis D virus

Causes

Hepatitis D virus (HDV) is only found in people who carry the hepatitis B virus. HDV may make a hepatitis B infection or existing hepatitis B liver disease worse. It can cause symptoms in people with hepatitis B virus who never had symptoms.

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

Risk factors include:

Symptoms

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

Symptoms may include:

Exams and Tests

Treatment

The treatment is the same as for hepatitis B. See hepatitis B.

Persons with long-term HDV infection may receive a medicine called alpha interferon or a liver transplant.

Outlook (Prognosis)

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).

Possible Complications

When to Contact a Medical Professional

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

Prevention

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.

A vaccine is available to prevent hepatitis B. It should be considered by people who are at high risk for hepatitis B infection.

Mandell GL, Bennett JE, Dolin R. Principles and Practice of Infectious Diseases. 5th ed. London: Churchill Livingstone; 2000:1870-1871.

Long SS, Pickering LK, Prober CG. Principles and Practice of Pediatric Infectious Diseases. 2nd ed. New York, NY: Elsevier; 2003:1097-1101.