The researchers showed that HCV entered Scotland during the 1930s and 1940s while also spreading to other countries throughout the world, probably through the mass treatment of soldiers in field hospitals.
In the study published in the Journal of Virology, scientists from the MRC-University of Glasgow centre for virus research and NHS virus diagnostics labs describe how they examined the spread of HCV across Scotland by comparing the sequence of virus strains in infected individuals across various geographical areas.
The study showed transmission of the virus started to increase in the 1970s with different strains originating in Glasgow and Edinburgh. The Glasgow strains subsequently spread to other regions of Scotland.
It was not until several decades later, in the 1990s, that extensive HCV transmission was observed in Aberdeen and the predominant strain was one that was rarely identified outside of Aberdeenshire.
Looking in more detail at the Glasgow strains, they were able to identify the key areas of the city involved in the spread of the virus up to the present day. Focusing treatment and preventative measures in these regions could help to reduce the prevalence of HCV in Scotland.
It is estimated that 36,700 people in Scotland are currently infected with HCV.
The virus infects the liver and causes a chronic infection which may remain undetected for decades before symptoms occur.
HCV is a blood-borne virus which was once spread through the use of unscreened blood and blood products or through using unsterilized medical equipment such as syringes.
Nowadays, transmission of the virus in the UK is associated mainly, but not exclusively, with the sharing of needles during injecting drug use. Understanding how HCV spreads could support national initiatives such as the Hepatitis C Action plan to prevent transmission of the virus, to treat infected individuals and to monitor the appearance of drug-resistant strains.
Dr Carol McWilliam Leitch, of the centre for virus research,lead scientist of the study, said: “HCV poses a significant public health challenge in Scotland as well as globally.
“There is currently no vaccine against the virus and the recently developed antiviral drugs are not only extremely costly, but resistant strains have already emerged.
“Pinpointing regions of Scotland driving HCV spread will allow us to more effectively target treatments, monitor their effect and track resistant strains. These measures are essential if we are to combat the virus. We now intend to focus our attention on HCV spread in other Scottish regions and to extend the study across the UK”.