The Cedar Project: high incidence of HCV infections in a longitudinal study of young Aboriginal people who use drugs in two Canadian cities

Wayne M Christian,Negar Chavoshi,Patricia M Spittal,Mary Teegee,Akm Moniruzzaman,Martin T Schechter,Margo E Pearce

doi:10.1186/1471-2458-12-632

Abstract

BackgroundFactors associated with HCV incidence among young Aboriginal people in Canada are still not well understood. We sought to estimate time to HCV infection and the relative hazard of risk factors associated HCV infection among young Aboriginal people who use injection drugs in two Canadian cities.MethodsThe Cedar Project is a prospective cohort study involving young Aboriginal people in Vancouver and Prince George, British Columbia, who use illicit drugs. Participants’ venous blood samples were drawn and tested for HCV antibodies. Analysis was restricted to participants who use used injection drugs at enrolment or any of follow up visit. Cox proportional hazards regression was used to identify independent predictors of time to HCV seroconversion.ResultsIn total, 45 out of 148 participants seroconverted over the study period. Incidence of HCV infection was 26.3 per 100 person-years (95% Confidence Interval [CI]: 16.3, 46.1) among participants who reported using injection drugs for two years or less, 14.4 per 100 person-years (95% CI: 7.7, 28.9) among participants who had been using injection drugs for between two and five years, and 5.1 per 100 person-years (95% CI: 2.6,10.9) among participants who had been using injection drugs for over five years. Independent associations with HCV seroconversion were involvement in sex work in the last six months (Adjusted Hazard Ratio (AHR): 1.59; 95% CI: 1.05, 2.42) compared to no involvement, having been using injection drugs for less than two years (AHR: 4.14; 95% CI: 1.91, 8.94) and for between two and five years (AHR: 2.12; 95%CI: 0.94, 4.77) compared to over five years, daily cocaine injection in the last six months (AHR: 2.47; 95% CI: 1.51, 4.05) compared to less than daily, and sharing intravenous needles in the last six months (AHR: 2.56; 95% CI: 1.47, 4.49) compared to not sharing.ConclusionsThis study contributes to the limited body of research addressing HCV infection among Aboriginal people in Canada. The HCV incidence rate among Cedar Project participants who were new initiates of injection drug use underscores an urgent need for HCV and injection prevention and safety strategies aimed at supporting young people surviving injection drug use and sex work in both cities. Young people must be afforded the opportunity to provide leadership and input in the development of prevention programming.

Highlights

Factors associated with HCV incidence among young Aboriginal people in Canada are still not well understood
In British Columbia, it is estimated that incidence for HCV infection is twice as high among Aboriginal people compared to non-Aboriginal people [5] and that over half the population of Aboriginal people living with HIV are HCV co-infected, making the treatment challenges associated with being HCV and HIV co-infected far more complex [6]
Results presented in this study suggest that even in the presence of established harm reduction initiatives in both Vancouver and Prince George, including fixed and mobile needle distribution sites, young Aboriginal people who use drugs are at sustained risk for HCV infection

Summary

Introduction

Factors associated with HCV incidence among young Aboriginal people in Canada are still not well understood. Increasing levels of HCV infection among young Aboriginal people are distressing for many Aboriginal communities and service providers, in small and large urban centres and in rural settings where healthcare resources are limited [1,2]. National HCV surveillance data for indigenous people in Canada is considered to be very limited largely because of under reporting and lack of consistent documentation of ethnic status between provinces [7,8] Despite these limitations the Public Health Agency of Canada has identified that HCV incidence among Aboriginal people in Canada is 5 to 6 fold higher than among nonAboriginal people [8]. The majority of these new infections can be attributed to injection drug use and the sharing of contaminated injection equipment [7,9]

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Discussion

Conclusion