July 28, 2011
A recent report offers fresh evidence that needle-exchange programs (NEPs) and opiate substitution therapy (OST) can reduce injection drug users' (IDUs) odds of contracting hepatitis C virus (HCV).
Senior researcher Matthew Hickman, a professor of public health at the University of Bristol, and colleagues pooled the results of six previous studies of UK programs (based in Birmingham, Bristol, Glasgow, Leeds, London, and Wales). The results showed that IDUs with the highest coverage of NEPs were about half as likely to contract HCV as others.
Among the group of IDUs who said they accessed enough clean needles for all their injections, slightly less than 4 percent tested HCV-positive during the studies, which lasted as long as one year. This compares to 7 percent for IDUs who said they did not receive clean needles for all their injections.
Among IDUs who were currently on OST, the rate of new HCV infection was 3 percent, compared to 7 percent for those not on OST.
For IDUs who were participating in NEPs and OST, the new HCV infection rate was just 2 percent.
The authors noted the study's limitations, including that its findings are based on small numbers and concerned only UK programs. Still, Hickman believes the work fills some knowledge gaps relating to how well IDU programs are working.
One question for future research, Hickman said, is whether treating HCV infection in IDUs helps reduce onward transmission.
The authors concluded, "There is good evidence that uptake of opiate substitution therapy and high coverage of needle and syringe programs can substantially reduce the risk of HCV transmission among IDUs. Research is required now on whether the scaling-up of intervention exposure can reduce and limit HCV prevalence in this population."
The study, "The Impact of Needle and Syringe Provision and Opiate Substitution Therapy on the Incidence of Hepatitis C Virus in Injecting Drug Users: Pooling of UK Evidence," was published in Addiction (2011;doi:10.1111/j.1360-0442.2011.03515.x).