> Hepatitis E virus (HEV) causes Hepatitis E, a liver disease (liver inflammation).

Virology-
> HEV is a spherical, nonenveloped, RNA virus that is approximately 32-34 nm in    diameter.
> It was previously classified family Caliciviridae. However, its genome more closely    resembles the rubella virus. It is now classified as the only member of the genus    Hepevirus, and that genus has not yet been assigned to a family.
> Particles are often found in faeces and are presumed to represent degraded viral    particles.
> Hepatitis E virus has been assigned to genus hepatitis E like virus.
> Based on its physicochemical properties it is presumed to be a calici-like virus.

Genome organization:
> Genome contains a single-strand of positive-sense RNA that is approximately 7300    bases in length that is capped and polyadenylated. The genome is organized into    three partially overlapping open reading frames (ORFs), designated 1, 2 and 3each    expressing different proteins.The 27-35 nt long 5' non-coding region (NCR) is followed    by the largest ORF (ORF1), of ~5 kb, codes for the nonstructural proteins (methyl    transferase, protease, helicase and replicase ;) of 1693 aa, responsible for viral    replication.ORF-2(of ~2 kb) contains genes encoding the capsid.The function of    ORF-3 is unknown, but the antibodies directed against ORF-3 epitopes have been    identified.

Replication:
> HEV replicates in the hepatocytes and is excreted in stool
> A general model of HEV replication has been proposed, based on similarities and    sequence homology to other more completely characterized +RNA viruses.
> As HEV enters into a permissive cell, the viral genomic RNA is translated in the cytosol    of infected cells to produce the nonstructural ORF1-encoded polyprotein (nsP).This    nsP is postulated to replicate the genomic positive strand into the negative strand    replicative intermediate. This intermediate is postulated to act as a template for the    synthesis of additional copies of the genomic positive strand as well as a subgenomic    positive strand.
> The proposed subgenomic positive-strand HEV RNA can then be translated into the    structural protein(s) at late stages of viral replication. The structural (capsid) protein    then probably packages the viral genome to form progeny virions.