HIV/AIDS in Vancouver, British Columbia: a growing epidemic.

Colin W Mcinnes,Robert S Hogg,Eric Druyts,Mark W Tyndall,Stephanie S Harvard,Viviane D Lima,Mark Gilbert,Julio Sg Montaner,Evan Wood

doi:10.1186/1477-7517-6-5

Abstract

The prevalence of HIV in Vancouver, British Columbia was subject to two distinct periods of rapid increase. The first occurred in the 1980s due to high incidence among men who have sex with men (MSM), and the second occurred in the 1990s due to high incidence among injection drug users (IDU). The purpose of this study was to estimate and model the trends in HIV prevalence in Vancouver from 1980 to 2006. HIV prevalence data were entered into the UNAIDS/WHO Estimation and Projection Package (EPP) where prevalence trends were estimated by fitting an epidemiological model to the data. Epidemic curves were fit for IDU, MSM, street-based female sex trade workers (FSW), and the general population. Using EPP, these curves were then aggregated to produce a model of Vancouver's overall HIV prevalence. Of the 505 000 people over the age of 15 that reside in Vancouver, 6108 (ranging from 4979 to 7237) were living with HIV in the year 2006, giving an overall prevalence of 1.21 percent (ranging from 0.99 to 1.43 percent). The subgroups of IDU and MSM account for the greatest proportion of HIV infections. Our model estimates that the prevalence of HIV in Vancouver is greater than one percent, roughly 6 times higher than Canada's national prevalence. These results suggest that HIV infection is having a relatively large impact in Vancouver and that evidence-based prevention and harm reduction strategies should be expanded.

Highlights

All data were entered into the UNAIDS/WHO Estimation and Projection Package (EPP) [4], where prevalence trends for each population subgroup were estimated longitudinally by fitting an epidemic curve to the data for each subgroup
Our models estimate that men who have sex with men (MSM) and injection drug users (IDU) subgroups contributed the greatest number of infections, with 3000 and 2295 individuals, respectively
The model illustrates the rise in HIV prevalence among MSM in the 1980s as well as the rapid increase in prevalence among IDU and female sex trade workers (FSW) in the 1990s

Summary

Introduction

In the 1980s, most HIV infections were accounted for by sexual transmission among men who have sex with men (MSM), and in the mid-1990s a rapid increase in HIV incidence was observed among injection drug users (IDU) and street-based female sex trade workers (FSW) [1,2]. This shift in HIV trends was well documented, it has not been adequately quantified or characterized in the historical context of the city's HIV epidemic. The purpose of this study was to combine estimates of HIV prevalence among population subgroups in Vancouver in order to model the prevalence trends of these subgroups and Vancouver's overall population longitudinally from 1980 to 2006

Objectives

Methods

Results

Conclusion