ICTV Virus Taxonomy Profile: Hepeviridae

Abstract

The family Hepeviridae includes enterically transmitted small non-enveloped positive-sense RNA viruses. It includes the genera Piscihepevirus, whose members infect fish, and Orthohepevirus, whose members infect mammals and birds. Members of the genus Orthohepevirus include hepatitis E virus, which is responsible for self-limiting acute hepatitis in humans and several mammalian species; the infection may become chronic in immunocompromised individuals. Extrahepatic manifestations of Guillain-Barré syndrome, neuralgic amyotrophy, glomerulonephritis and pancreatitis have been described in humans. Avian hepatitis E virus causes hepatitis-splenomegaly syndrome in chickens. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Hepeviridae, which is available at www.ictv.global/report/hepeviridae.

Keywords: Hepeviridae; ICTV; avian hepatitis E virus; hepatitis E virus; piscihepevirus; swine hepatitis E virus; taxonomy.

Fig. 1.

Negative contrast electron micrograph of human hepatitis E virus virions from a case stool collected in Nepal. (A) virion and (B) empty capsid. The bar represents 100 nm (photograph from M. Purdy).

Fig. 2.

Genome organization of cutthroat trout virus and human hepatitis E virus. A short 5′ non-coding region is followed by ORF1, encoding non-structural proteins including the putative functional domains: MT, methytransferase; P, a putative papain-like cysteine protease; HUD, Hepeviridae unique domain, also called the Z domain [7]; PP, a hypervariable polyproline region that is dispensable for virus infectivity; Macro, macro domain; Hel, helicase; and RdRP, RNA-dependent RNA polymerase [7, 8]. ORF2 encodes a capsid protein and is followed by a short 3′ NCR. ORF3 overlaps ORF2 in a different reading frame and encodes a small phosphoprotein with a multi-functional C-terminal region. The scale is in bases.