II. Epidemiology
- Endemic Hepatitis B Regions
- Mediterranean basin
- South America
III. Risk Factors: Transmission
- Percutaneous spread via Intravenous Drug Abuse
- Transfusion (e.g. Hemophilia)
- Sexual contact
IV. Pathophysiology
- Defective 37 nm RNA virus
- Contains a helical nucleocapsid
- Relies on HBV's envelope (HBsAg)
- Requires Hepatitis BVirus for replication
- Enhances severity of Hepatitis B infection
- Infection is via 2 mechanisms
- Coinfection with Hepatitis B
- In many cases, patients develop Immunity to Hepatitis B (xHBsAb positive), rendering HDV inactive
- Superinfection of a Chronic Hepatitis B Infection or Hepatitis B Carrier
- Associated with severe Acute Hepatitis
- Complications include Fulminant Hepatitis, Cirrhosis and a high mortality (5-15%)
- Coinfection with Hepatitis B
V. Differential Diagnosis
VI. Labs
- Hepatitis D Serology (xHDV) IgM and IgG
- Higher titers suggest chronic Hepatitis D
- High False Negative Rate (HDV Antibody is short lived in serum)
VII. Management
VIII. Complications (esp. when HDV superinfects a patient with chronic HBV)
- Fulminant Hepatitis
- Chronic Hepatitis
- Cirrhosis
IX. Prevention
- Hepatitis B Vaccine for Non-Carriers of Hepatitis B
X. References
- Gladwin, Trattler and Mahan (2014) Clinical Microbiology, Medmaster, Fl, p. 261-2
- Pan (2023) Dig Dis Sci 68(8):3237-48 +PMID: 37338616 [PubMed]