The Origin of Hepatitis C Virus
The origin of hepatitis C virus (HCV) can be conceptualised at several levels. Firstly, origins might refer to its dramatic spread throughout the Western world and developing countries throughout the twentieth century. As a blood-borne virus, this epidemic was fuelled by new parenteral transmission routes associated with medical treatments, immunisation, blood transfusion and more recently injecting drug use. At another level, however, origins might refer to the immediate sources of HCV associated with its pandemic spread, now identified as areas in Central and West sub-Saharan Africa and South and South East Asia where genetically diverse variants of HCV appear to have circulated for hundreds of years. Going back a final step to the actual source of HCV infection in these endemic areas, non-human primates have been long suspected as harbouring viruses related to HCV with potential cross-species transmission of variants corresponding to the 7 main genotypes into humans. Although there is tempting analogy between this and the clearly zoonotic origin of HIV-1 from chimpanzees in Central Africa, no published evidence to date has been obtained for infection of HCV-like viruses in either apes or Old World monkey species. Indeed, a radical re-think of both the host range and host-specificity of hepaciviruses is now required following the very recent findings of a non-primate hepacivirus (NPHV) in horses and potentially in dogs. Further research on a much wider range of mammals is needed to better understand the true genetic diversity of HCV-like viruses and their host ranges in the search for the ultimate origin of HCV in humans.
KeywordsNucleotide Sequence Divergence Domestic Horse Ultimate Origin Recent Spread Pandemic Spread
- Choo QL, Kuo G, Weiner AJ, Overby LR, Bradley DW, Houghton M (1989) Isolation of a cDNA derived from a blood-borne non-A, non-B hepatitis genome. Sci 244:359–362Google Scholar
- Pepin J, Labbe AC (2012) Noble goals, unforeseen consequences: control of tropical diseases in colonial Central Africa and the iatrogenic transmission of blood-borne viruses. Trop Med Int Health 16:744–753Google Scholar
- Simmonds P, Becher P, Collett MS, Gould EA, Heinz FX, Meyers G, Monath T, Pletnev A, Rice CM, Stiasny K, Thiel HJ, Weiner A, Bukh J (2011) Flaviviridae. In: King AMQ, Adams MJ, Carstens EB, Lefkowitz EJ (eds) Virus taxonomy. Elsevier, Oxford, pp 1003–1020Google Scholar