Virus
Hepatitis D virus
Defective satellite virus needing HBV
hep-uh-TY-tis DEE VY-rus
High-yield clue
HDV borrows the hepatitis B surface antigen (HBsAg) envelope, so it only causes disease alongside HBV.
Overview
A defective (satellite) virus with a small circular negative-sense RNA genome and delta antigen that can only complete its cycle in cells already infected by hepatitis B, making it a classic teaching example of viral dependence.
Classification
- RNA virus
- Circular negative-sense RNA genome
- Family Kolmioviridae, genus Deltavirus
- Defective/satellite virus
Lab & identification clues
- Delta antigen concept
- Anti-HDV serology vocabulary
- HBsAg-dependent envelopment/assembly concept (genome replication uses host RNA polymerase II)
- Coinfection vs superinfection distinction
Associations
- Requires concurrent hepatitis B infection
- Coinfection vs HBV superinfection study framing
- More severe or accelerated liver injury vocabulary
- Parenteral and sexual transmission overlap with HBV
Commonly confused with
- Hepatitis B virus
- Hepatitis C virus
Your notes
Original student-study summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment, dosing, or specimen-handling guidance.