Hepatitis C Virus in Dogs

An estimated 3% of the world's population is chronically infected with Hepatitis C Virus. According to the WHO, 130–150 million people globally have a chronic Hepatitis C infection and a significant number of those who are chronically infected will develop liver cirrhosis or liver cancer. Approximately 500,000 people die each year from Hepatitis C-related liver diseases[1].

Although the Hepatitis C Virus was discovered about 25 years ago, its origin remained obscure largely because no closely related animal virus homolog had been identified before 2011.

In 2011 scientists reported the identification in domestic dogs of a nonprimate hepacivirus. Analysis of the canine hepacivirus or Canine Hepatitis C Virus confirmed it to be the most genetically similar animal virus homolog of (Human) Hepatitis C Virus[2].

Further analysis suggested a divergence time of the most recent ancestor of both viruses within the past 500-1,000 years, well after the domestication of canines. Which might mean that dogs got the virus from humans.

Non-human primates have been long suspected as harbouring viruses related to (Human) Hepatitis C Virus. A radical re-think of both the host range and host-specificity of Hepatitis C Viruses is now required following the these findings of a non-primate hepacivirus (NPHV) in horses and in dogs. Further research on a much wider range of mammals is needed to better understand the true genetic diversity of Hepatitis C-like viruses and their host ranges in the search for the ultimate origin of Hepatitis C Virus in humans[3].

[1] Lozano et al: Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: a systematic analysis for the Global Burden of Disease Study in The Lancet - 2012
[2] Kapoor et al: Characterization of a canine homolog of hepatitis C virus in Proceedings of the National Academy of Sciences - 2011
[3] Simmonds: The origin of hepatitis C virus in Current Topics in Microbiology and Immunology - 2013