Ramping up testing and treatment for hepatitis C in prisons cuts new infections by 57% and reinfections by 41%, according to a landmark study.

The world-first study is the biggest evaluation of so-called ‘treatment-as-prevention’ for hepatitis C in any setting, as well as the first in prisons, say the authors, from the Kirby Institute at UNSW Sydney.

Their study of 3700 prisoners (82% male) across four prisons in NSW — two maximum security and two medium security — found treatment of hepatitis C led to a significant overall reduction in incidence by disrupting chains of transmission.

Some 719 participants (19%) were hepatitis C positive at baseline and offered treatment, although more than 300 were released or transferred before the researchers could offer treatment.