New hepatitis C diagnoses in Ontario, Canada are associated with the local prescription patterns of a controlled-release opioid.

Increases in acute hepatitis C virus (HCV) incidence may be a result of the rising prevalence of injection drug use and the opioid epidemic. Among persons who inject drugs, sharing of needles/syringes is less common and leads to a smaller proportion of incident cases than does sharing of injection drug preparation equipment. In Canada and Europe, hydromorphone controlled release has been associated with frequent reuse and sharing of IDPE. Drug excipients within HCR have been shown to preserve virus survival within IDPE. We hypothesized that regional differences in HCV incidence would mirror regional differences in HCR prescribing. We reviewed HCV incidence data across Ontario, Canada for 2016. Opioid prescribing patterns in each Health Unit were reviewed. Multivariable Poisson regression analyses were performed to test the strength of hydromorphone controlled release dispensing patterns in explaining HCV incidence compared to all opioids. Less vehicle access, lack of education, lower income, less population density, higher white race/ethnicity and more opioid substitution therapy recipients remained significant positive predictors of hepatitis C incidence in the Ontario model. Higher hydromorphone controlled release dispensing rate was a stronger predictor of HCV incidence than all opioid prescriptions (standardized risk ratio = 1.17, P < .0001 vs sRR = 1.11, P = .02). When hydromorphone controlled release was excluded from the opioid prescription variable, dispensing patterns of all other opioids no longer remained a significant predictor (sRR = 1.042, P = .34). The observed relationship between HCV incidence and hydromorphone controlled release dispensing suggests that the type of opioid prescribed locally may contribute to variations in HCV incidence. These data add support to evidence that hydromorphone controlled release use is contributing to HCV spread in Ontario.