The prevalence of hepatitis C worldwide is largely unknown because most people have no symptoms in the early stages and are unaware they have been infected. The World Health Organisation estimates that 3% of the world’s population is infected, with around five million of these in Western Europe. There are estimated to be around 250,000 people in the UK infected with hepatitis C. Some speculate this could be higher. Current studies suggest that approximately 50% of active injectors have hepatitis C. The prevalence of HCV varies geographically, with some inner city areas having much higher rates and lower rates in some rural areas.
Injection in prison carries a high risk of infection because sharing dirty equipment is common. Some research suggests significant numbers of injectors may become infected while in prison.