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. Later, distinct lineages were isolated from horses in different locations.^{[citation needed]}

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.^{[citation needed]}

The overall G+C content is 50.7%.^{[citation needed]}

Evolution

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

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]

References

1. Smith, Donald B.; et al. (23 June 2016). "Create 13 new species in the genus Hepacivirus and rename 1 species (family Flaviviridae)" (PDF). International Committee on Taxonomy of Viruses (ICTV). p. 3. Retrieved 13 March 2019. All other species are named according to the date of publication of a complete coding sequence with the exception of Hepacivirus B which includes GBV-B (providing a memorable link) and Hepacivirus A (canine hepacivirus/non-primate hepacivirus).
2. Kapoor A, Simmonds P, Gerold G, Qaisar N, Jain K, Henriquez JA, Firth C, Hirschberg DL, Rice CM, Shields S, Lipkin WI (2011). "Characterization of a canine homolog of hepatitis C virus". Proc. Natl. Acad. Sci. U.S.A. 108 (28): 11608–13. Bibcode:2011PNAS..10811608K. doi:10.1073/pnas.1101794108. PMC 3136326. PMID 21610165.
3. Pybus, Oliver G; Thézé, Julien. "Hepacivirus cross-species transmission and the origins of the hepatitis C virus" (PDF). evolve.zoo.ox.ac.uk. Archived from the original (PDF) on 2021-12-05. Retrieved December 5, 2021.