In a group of young users of injection drugs, recent maintenance opioid agonist therapy with methadone or buprenorphine for opioid use disorders, such as heroin addiction, was associated with a lower incidence of hepatitis C virus (HCV) infection and may be an effective strategy to reduce injection-drug use and the resulting spread of HCV, according to a study published online by JAMA Internal Medicine.

The use of injection drugs is a main route of transmission for HCV infection. Younger drug users are an important group to target because they are at the core of HCV infections. Interventions that can prevent HCV infections are vital. Previous studies have suggested that opioid agonist therapy may reduce the incidence of HCV infection but little was known about the effect of this therapy in young drug users.

Researchers Judith I. Tsui, M.D., M.P.H., of the Boston University School of Medicine, and colleagues examined the effects in a group of 552 young injection-drug users in San Francisco from January 2000 through August 2013. The median age of the drug users was 23 years; most of the drug users were male, white and homeless. The median duration of drug use was 3.6 years and 33.3 percent of participants were daily drug users. Nearly 60 percent of drug users reported heroin as the drug they had used most often in the past month. While most participants (82.4 percent) reported receiving no substance use treatment in the prior year, 4.2 percent reported having had maintenance opioid agonist treatment in the prior year.

During the study observation period, there were 171 cases of HCV for an incidence rate of 25.1 per 100 person-years. Participants who reported maintenance opioid agonist therapy in the past three months had a lower incidence of HCV infection compared with those participants who reported no therapy.

"Young injection drug users are a major driving force in the epidemic of HCV infection in the United States and Canada and therefore are an important target for prevention. … Our results suggest that treatment for opioid use disorders with maintenance opioid agonist therapy can reduce transmission of HCV in young adult injection drug users and should be offered as an important component of comprehensive strategies for prevention of primary HCV infection," the authors conclude.