II. Epidemiology

  1. Endemic Hepatitis B Regions
    1. Mediterranean basin
    2. South America

III. Risk Factors: Transmission

  1. Percutaneous spread via Intravenous Drug Abuse
  2. Transfusion (e.g. Hemophilia)
  3. Sexual contact

IV. Pathophysiology

  1. Defective 37 nm RNA virus
    1. Contains a helical nucleocapsid
    2. Relies on HBV's envelope (HBsAg)
    3. Requires Hepatitis BVirus for replication
  2. Enhances severity of Hepatitis B infection
  3. Infection is via 2 mechanisms
    1. Coinfection with Hepatitis B
      1. In many cases, patients develop Immunity to Hepatitis B (xHBsAb positive), rendering HDV inactive
    2. Superinfection of a Chronic Hepatitis B Infection or Hepatitis B Carrier
      1. Associated with severe Acute Hepatitis
      2. Complications include Fulminant Hepatitis, Cirrhosis and a high mortality (5-15%)

V. Differential Diagnosis

VI. Labs

  1. Hepatitis D Serology (xHDV) IgM and IgG
    1. Higher titers suggest chronic Hepatitis D
    2. High False Negative Rate (HDV Antibody is short lived in serum)

VII. Management

VIII. Complications (esp. when HDV superinfects a patient with chronic HBV)

  1. Fulminant Hepatitis
  2. Chronic Hepatitis
  3. Cirrhosis

IX. Prevention

  1. Hepatitis B Vaccine for Non-Carriers of Hepatitis B

X. References

  1. Gladwin, Trattler and Mahan (2014) Clinical Microbiology, Medmaster, Fl, p. 261-2
  2. Pan (2023) Dig Dis Sci 68(8):3237-48 +PMID: 37338616 [PubMed]

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