Subfamily: Orthohepevirinae

Genus: Rocahepevirus

 

Distinguishing features

Members of the genus Rocahepevirus are phylogenetically distinct from other viruses in the subfamily, and have a different host range, being found only in rodents, shrews and carnivores. Members of the species Rocahepevirus ratti of genotype C1 infect and are pathogenic for humans (Sridhar et al., 2018Andonov et al., 2019Reuter et al., 2020Sridhar et al., 2021Rivero-Juarez et al., 2022).

Biology

Serological reactivity to members of the species Rocahepevirus ratti has been detected in 25% of brown rats (Rattus norvegicus) from Germany, with virus RNA detected in 10% of animals (Johne et al., 2010bJohne et al., 2012); a higher frequency of seroreactivity was reported in rats from the USA (Purcell et al., 2011). Genetically similar viruses have been detected in a variety of other host species; genotype C1 in rodents (Rattus sp., Bandicota indica) and eulipotyphlids (musk shrew, Suncus murinus) and humans (Sridhar et al., 2018Andonov et al., 2019Reuter et al., 2020Sridhar et al., 2021Rivero-Juarez et al., 2022),while genotype C2 has been detected in mustelids (ferret and mink). Viruses of this species appear similar to those of the genus Paslahepevirus in electron microscopy structure and hepatotropism, although following experimental transmission liver enzymes levels were unaltered (Johne et al., 2010aPurcell et al., 2011); other biological features are unknown. Members of other species have been detected in voles (Ryll et al., 2019), while unclassified viruses in the genus have been detected in hamsters (Wu et al., 2018) and the hairy tailed bolo mouse.

Species demarcation criteria

Members of different species in the genus are phylogenetically distinct based upon analysis of ORF1 codon positions 1−450 (methyltransferase), ORF1 codon positions 971–1692 (RNA-directed RNA polymerase) and ORF2 codon positions 121−473 (capsid protein not including the region encoded by the overlapping ORF3). Members of different species may also have different host ranges, although limited data is available.

Related, unclassified viruses

Virus

Host

Accession number

fox hepatitis E virus

fox (Vulpes vulpes)

KC692370KC692369

hepevirus sp. isolate RtCb-HEV/HeB2014

striped dwarf hamster (Cricetulus barabensis)

KY432899

Necromys lasiurus hepatitis E virus

 

hairy tailed bolo mouse (Necromys lasiurus)

MG021328

hepevirus sp. isolate RtCm-HEV/XJ2016

 

grey dwarf hamster (Cricetulus migratorius)

KY432903

Virus names and virus abbreviations are not official ICTV designations.

The hamster and bolo mouse viruses have not been classified because of their ambiguous position in phylogenetic trees using sequences from different genome regions.