Hepatitis D virus (HDV) is a very peculiar virus that shares many characteristics with plant viroids. One of its unique characteristics is the requirement for the presence of a helper virus for its replication, and in particular enveloping its virion, a role often played by the hepatitis B virus (HBV). Infection with HDV is frequently associated with more severe disease, which may present with fulminant hepatitis or a more rapid progression to cirrhosis and hepatocellular carcinoma (HCC), when compared to HBV mono-infection. HDV exhibits many peculiarities and enigmas, which have led to it being considered a neglected virus. This review aims to identify the most important gaps in knowledge and peculiarities in the study of this enigmatic virus, from virology to clinical implications.
Pujol et al. (Sat,) studied this question.