Methadone and buprenorphine maintenance therapies used to treat opioid use disorders, like heroin addiction, are significantly reducing the incidence of hepatitis C infection, according to a research team that includes University of New Mexico School of Medicine’s Kimberly Page, PhD, along with colleagues at the University of California San Francisco and Boston University.

“New interventions that can prevent HCV infections are vital,” Page says. The research team thinks it might be an effective strategy to reduce injection-drug use and the resulting spread of hepatitis C virus (HCV), which is occurring at an alarming rate. The study was published online October 27 by JAMA Internal Medicine.

A main route of HCV transmission is the use of injection drugs, and younger drug users are at the core of the HCV epidemic. Previous studies have suggested that opioid agonist therapy might reduce the incidence of HCV infection overall, but little was known about the effect of this therapy in younger drug users.

In this study, these effects in a group of 552 young injection-drug users in San Francisco were examined from January 2000 through August 2013. The median age of the drug users was 23 years and most were male, white and homeless. The median duration of drug use was 3.6 years, and one-third of participants were daily drug users. Nearly 60 percent of the injection-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 same period. 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 by two-thirds 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 U.S. and Canada, with as many as 25 percent becoming infected after two years of injecting,” the study authors note. “They 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 research was supported by grants from the National Institute on Drug Abuse, National Institutes of Health and other sources. Page is a leading national expert in hepatitis prevention research with the UNM School of Medicine’s Department of Internal Medicine, Division of Epidemiology, Biostatistics and Preventive Medicine.