The origin of hepatitis C virus

Area of Science:

• Virology
• Epidemiology
• Evolutionary Biology

Background:

• The hepatitis C virus (HCV) epidemic has spread globally, primarily through parenteral transmission routes.
• Genetically diverse HCV variants have circulated for centuries in Central/West sub-Saharan Africa and South/South East Asia.
• Non-human primates were previously suspected as the source of HCV, analogous to HIV-1 origins.

Purpose of the Study:

• To investigate the ultimate origin of the hepatitis C virus (HCV) in humans.
• To explore the host range and host-specificity of hepaciviruses.
• To understand the genetic diversity of HCV-like viruses.

Main Methods:

• Review of historical epidemic spread and transmission routes.
• Analysis of genetic diversity in suspected endemic regions.
• Consideration of recent findings on non-primate hepacivirus (NPHV) in horses and dogs.

Main Results:

• HCV spread widely in the 20th century via medical treatments, transfusions, and drug use.
• No evidence of HCV-like viruses found in apes or Old World monkeys.
• Recent discovery of NPHV in horses necessitates a broader search for hepacivirus origins.

Conclusions:

• The origin of HCV may not be solely linked to primates.
• A radical re-evaluation of hepacivirus host range and specificity is required.
• Further research across diverse mammal species is crucial to identify HCV's ultimate origin.