Hepacivirus A

Hepacivirus A, or Canine hepacivirus (CHV) or Equine hepacivirus (EHV), is a positive-sense single-stranded RNA virus of the genus Hepacivirus.^[2] It infects dogs and horses, and causes pulmonary infections in dogs. Unlike the related Hepatitis C virus, it is not known to cause hepatitis in either host.

Hepacivirus A
Virus classification
(unranked):	Virus
Realm:	Riboviria
Kingdom:	Orthornavirae
Phylum:	Kitrinoviricota
Class:	Flasuviricetes
Order:	Amarillovirales
Family:	Flaviviridae
Genus:	Hepacivirus
Species:	Hepacivirus A
Synonyms[1]
Canine hepacivirus Non-primate hepacivirus Equine hepacivirus

History

The virus was isolated in 2011 from a number of dogs suffering from respiratory infections.^[2] Later, distinct lineages were isolated from horses in different locations.^[3]

Genome

As of 2012, the genome has not yet been fully sequenced. The available sequence is about 6,500 nucleotides in length. It is predicted to have a polyprotein that can be cleaved into 10 smaller proteins. There is a 'slippery sequence' – A₅NNA₅ – within the genome which may encode a programmed frameshift. It encodes two envelope proteins (E1 and E2) as well as cysteine and serine proteases.^[2]

The overall G+C content is 50.7%.^[2]

Evolution

The virus appears to have evolved from the Hepatitis C virus between 500 and 1,000 years ago.^[2]

The equine lineages (EHV) are more diverse than the canine lineages (CHV), suggesting that the former are ancestral to the latter. CHV appears to have originated in a cross-species transmission from horses to dogs around 1970. The origin of EHV is not known, but it seems that both EHV and Hepatitis C virus have originated in separate cross-species transmission events from a common source.^[3]