People who inject drugs (PWID) and receive mental health counselling or opioid substitution therapy could be less likely to reacquire hepatitis C, a new study has found.
Conducted by School of Population and Public Health (SPPH) and British Columbia Centre for Disease Control (BCCDC) researchers, the findings could open up opportunities for treatment for this at-risk group, the authors said.
Published in the Lancet Gastroenterology & Heptaology in December, the study looked at 5,915 individuals who had been cleared of hepatitis C between 1992 and 2013, using the B.C. Hepatitis Testers Cohort. It is the largest population–based cohort with the largest number of reinfections in such a study so far, the authors said.
SPPH doctoral candidate Nazrul Islam
Eight per cent, or 452 people, developed hepatitis C again, with an average rate of reinfection of 1.27 cases per 100 person-years, from a total of 35,672 person-years of follow-up, a unit measuring the rate of cases of reinfection by the number of people, and the years each individual took part in the study. The median follow up time was about five years.
While people who inject drugs had a higher risk of reinfection at 1.53 cases per 100 person-years, among the 1,604 with a current history of injection drug use, those who took part in opioid substitution therapy resulted in a 27% drop in reinfection risk, and those who received mental health counselling services had a 29% lower risk of reinfection, controlling for other risk factors.
The paper said reinfection with hepatitis C is a concern because clearing the disease from an individual’s system does not provide immunity, and while direct-acting antivirals are the new gold-standard for hepatitis C treatment, they cost a lot of money.
Lead author and SPPH doctoral candidate Nazrul Islam said the study showed that the health care system should engage with people who inject drugs more, and provide harm reduction services with hepatitis C treatment to reduce the risk of future reinfection.
“Direct-acting antivirals are expensive. To get the best out of it, so we don’t have to spend that money again, harm reduction activities are really helpful.”
— SPPH doctoral candidate Nazrul Islam
Clinical Associate Professor Naveed Janjua
People taking part in harm reduction initiatives such as opioid substitution therapy were more engaged with the healthcare system, and had more opportunity to speak with health practitioners about things like risky behaviours, he said.
Dr Islam’s supervisors are SPPH Professor Jean Shoveller and Clinical Associate Professor Naveed Janjua, who are also senior authors on the paper. Dr Janjua said the findings from this study are good news for patients, physicians and policy makers.
“Re-infection among people who use drugs could be mitigated through harm reduction interventions such as opioid substitution therapy.”
— Clinical Associate Professor Naveed Janjua
Dr Islam, who is in his fourth year of his doctoral candidacy, said future research would look into how the effects of harm reduction initiatives on hepatitis C reinfection risk evolve in the era of direct-acting antivirals.
This study was funded by the BCCDC and the Canadian Institutes of Health Research.