Hepatitis Delta Virus - HDV

Hepatitis Delta Virus - HDV

 

Hepatitis delta-agent virus (HDV) is a subviral agent that is dependent on the hepatitis B (HBV) virus for its life cycle; therefore, HDV infection cannot occur in the absence of HBV infection.

Epidemiology

  • Incidence – 1.25 million people in the U.S. are HBV infected
  • Estimated – 70,000 people in the U.S. are HDV infected
  • Transmission – parenteral

Organism

  • HDV is an RNA virus

Risk Factors

  • Transfusion with blood or blood products prior to 1990
    • Current transfusion risk is 1/400,000 units transfused
  • Organ transplant recipient
  • Hemodialysis
  • History of intravenous drug or intranasal cocaine use
  • Positive result for another blood-borne pathogen (eg, HBV, HIV)

Clinical Presentation

  • Two different disease courses – coinfection, superinfection
  • HBV/HDV coinfection
    • Disease process similar to HBV acute infection
    • 70-80% of chronic HBV patients who are co-infected with HDV develop fulminant liver failure
  • HDV superinfection superimposed on chronic HBV
    • Worsening liver disease
    • More common course associated with fulminant liver failure

Diagnosis

  • Laboratory testing
    • HDV antibodies
    • In acute co-infections, hepatitis D antigen (HDVAg) appears early, after hepatitis B virus surface antigen, and disappears with convalescence.
      • Acute HDV infections are associated with anti-HDV IgM antibody
      • Usually, only chronic cases demonstrate IgG antibody
      • Both antibodies usually disappear following convalescence
      • Simultaneous assessment of anti-hepatitis B virus core antibody IgM helps differentiate co-infections (present) from super-infections (absent)

Treatment

  • Acute HDV infection – supportive care
    • Chronic HDV infection – interferon-alfa, liver transplant

 


See Also