Hepatitis D Virus (HDV) is a small RNA virus with a rod-like structure that shows a higher prevalence in lower socioeconomic groups of the developing world.
HDV requires HBV for its in vivo transmission. Patients fall into 2 main categories:
(1) coinfection with both HBV and HDV
(2) as a superinfection of an HBV carrier.
The risk of chronic infection is much greater when there is superinfection of an HBV carrier.
Transmission: blood exposure, injection drug use, sexual contact, perinatally
Infection with HDV is associated with:
(1) acute or fulminant hepatitis
(2) rapid progression to chronic hepatitis
(3) significant risk for cirrhosis and hepatocellular carcinoma
The transmission risk has been decreased by HBV vaccination, but it can still be significant problem in unvaccinated patients.
Reasons to consider the diagnosis of HDV:
(1) fulminant HBV
(2) seronegative for HAV, HBC, HCV, and HEV
(3) rapid progression to cirrhosis
Diagnosis:
(1) demonstrate of delta antigen
(2) anti-HDV antibodies
