There was a significant reduction in hepatitis C incidence in Australia among injection drug users who attended needle and syringe programs, according to data published in the American Journal of Public Health.
“The decline in new cases of hepatitis C among people who inject drugs coincided with the expansion of programs like opioid substitution therapy and needle and syringe programs, which aim to minimize the spread of bloodborne viruses,” Jenny Iversen, a PhD candidate at the Kirby Institute at the University of New South Wales in Sydney, said in a press release. “We also found that fewer young people are starting to inject drugs and that the types of drugs people are injecting have changed, which may have contributed to a decline in the number of people contracting the virus.”
Iversen and colleagues conducted a passive retrospective study that included a cohort of 724 injection drug users who tested negative for HCV antibodies. The participants had been part of the annual Australian Needle and Syringe Programs Survey and had completed the survey for consecutive years or with only a 1-year gap from 1995 to 2010.
Among the 724 participants, 180 had HCV seroconversions, for a pooled incidence density of 17 per 100 person-years (95% CI, 14.68-19.66). The incidence density varied each year, peaking at 30.8 per 100 person-years in 2003 (95% CI, 21.3-44.6), then declining to 4 per 100 person-years in 2009 (95% CI, 1.3-12.3). In a multivariable analysis, independent predictors of HCV seroconversion included imprisonment in the previous 12 months, daily or more frequent injection, residence in mainland eastern Australia and injection of cocaine, heroin or other drugs, compared with injection of methamphetamine.
“These results demonstrate the value of ongoing investment in Australia’s internationally recognized system for the surveillance of HIV and hepatitis C among people who inject drugs,” Lisa Maher, PhD, head of the viral hepatitis epidemiology and prevention program at Kirby Institute, said in a press release. “This is the first time in the world this method has been used to estimate hepatitis C incidence and the first report of incidence in a national sample of people who inject drugs. It allows us to assess the uptake and impact of prevention and treatment interventions in this group.”
Disclosure: Iversen and Maher report no relevant financial disclosures.