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

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.

Assessing the impact and cost-effectiveness of needle and syringe provision and opioid substitution therapy on hepatitis C transmission among people who inject drugs in the UK: an analysis of pooled data sets and economic modelling

“…In total, we included 21 published studies 14,[39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58] and seven unpublished studies [33][34][35][36][37]59,60 comprising 1827 HCV incident infections and 8789.7 person-years of follow-up. Overall HCV infection incidence ranged between 0.09 and 42 cases per 100 person-years across the studies.…”

“…Twenty-one of the included studies reported the impact of OST, 14,20,39,40,[45][46][47]49,[51][52][53]55,57,58 including seven unpublished estimates. [33][34][35][36][37]59,60 Seventeen studies reported the impact of NSPs, 14,20,[41][42][43][44]47,48,50,54,56,58 including five unpublished sources, [33][34][35]59,60 and four reported combined measures of NSPs with OST, 14,33,44,47 including one unpublished data source.…”

“…Of the 28 studies, we pooled data from a total of 17 studies to assess the impact of current OST use on HCV infection incidence, 14,39,40,[45][46][47]49,52,53,55,56,58 including five unpublished estimates. 33,36,37,59,60 Current use of OST was defined as reporting use of OST within the past 6 months (yes or no) 33,46,49,58,60 or as reporting use of OST either within 6 months or > 6 months ago, 36 use of methadone at the time of survey, 39,47,52,59 continuous use of OST throughout the follow-up period, 40,45,53 with one study defining continuous use as daily use of methadone (any dosage) in the past 6 months 14 or in the past month.…”

“…33,36,37,59,60 Current use of OST was defined as reporting use of OST within the past 6 months (yes or no) 33,46,49,58,60 or as reporting use of OST either within 6 months or > 6 months ago, 36 use of methadone at the time of survey, 39,47,52,59 continuous use of OST throughout the follow-up period, 40,45,53 with one study defining continuous use as daily use of methadone (any dosage) in the past 6 months 14 or in the past month. 37 One study used a 3-month time frame to measure the use of opioid agonist therapy maintenance treatment.…”

“…Note: weights are from random-effects analysis Current OST use (last 6 months) Aitken, 2017 37 Bruneau, 2015 33 Craine, 2009 39 Crofts, 1997 40 Hope, 2015 59 Hope, 2015 59 Hope, 2015 59 Judd, 2015 36 Lucidarme, 2004 45 Maher, 2015 60 Mehta, 2015 34 Nolan, 2014 46 Palmateer, 2014 47 Spittal, 2012 52 Thiede, 2000 53 Tsui, 2014 55 Van Den Berg, 2007 14 White, 2014 58 White, 2014 58 Subtotal (I 2 = 31.7%; p = 0.092) FIGURE 3 Impact of current use of OST vs. no OST on HCV infection incidence findings from unadjusted analyses. Reproduced from Platt et al, 26,27 which are published open access under the terms of the Creative Commons Attribution-Non-Commercial Licence, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.…”