Outlier Populations: Individual and Social Network Correlates of Solvent-Using Injection Drug Users

Souradet Y Shaw,Ann Jolly ,John Wylie

doi:10.1371/journal.pone.0088623

Abstract

ObjectiveWe previously identified a high prevalence of Hepatitis C (HCV) amongst solvent-using injection drug users (S-IDU) relative to other injection drug users within the same locality. Here we incorporated social network variables to better characterize some of the behavioural characteristics that may be putting this specific subgroup of IDU at elevated disease risk.MethodsA cross-sectional survey of at-risk populations was carried out in Winnipeg, Canada in 2009. Individuals reporting any history of injection drug and/or solvent use were included in the study. Associations between subgroup membership, infection with HCV and HIV and individual and social network variables were examined.ResultsIn relation to other IDU, S-IDU were more likely to be infected with HCV, to report ever having shared a syringe, and to associate with other IDU. They were further differentiated in terms of their self-reported sexual orientation, ethnicity and in the injection drugs typically used.ConclusionSolvent use stands as a proxy measure of numerous other characteristics that put this group of IDU at higher risk of infection. Provision of adequate services to ostracized subpopulations may result in wider population-level benefits.

Highlights

Compared to HIV, there have been relatively fewer studies focusing on the public health impact of Hepatitis C (HCV)[1]
We further showed that recent syringesharing was 10 times higher among S-injection drug users (IDU)[34]
In the model building process above, special considerations were made in the manner in which the infection status variables were handled. These variables were included in the bivariate analysis and at the first stage of the model-building process to demonstrate and confirm that the infection/S-IDU association we identified in our 2003 study population existed in our 2009 study population[34]

Summary

Introduction

Compared to HIV, there have been relatively fewer studies focusing on the public health impact of Hepatitis C (HCV)[1] This is despite the substantial burden HCV infections pose to health systems. A US study published in 2011 estimated over 5 million individuals as having chronic HCV infection; in comparison, in 2009 the Centers for Disease Control estimated 1.2 million people living with HIV[2,3]. These two data sources place the death toll at similar levels, with 11,000 deaths attributed to HIV vs 8,000–11,000 deaths for HCV. This study estimated HCV contributed 8,823 years of premature mortality in the province of Ontario, as measured by years of life lost (YLL), compared to 5,036 YLL for HIV[4]

Methods

Results

Conclusion