Abstract
Objective: To estimate the number of prevalent and incident HIV infections in Canada in 2008.
Methods: We applied multiple methods to estimate national HIV prevalence and incidence in Canada, including the workbook method, two statistical modelling methods, and an iterative spreadsheet model.
Results: The estimated number of people living with diagnosed or undiagnosed HIV infection (including AIDS) continues to rise, from an estimated 57,000 in 2005 to 65,000 in 2008. Nearly half (48%) of these HIV-infected persons were men who have sex with men (MSM) and 22% were women. An estimated 16,900 persons with prevalent infection (26% of total prevalent infections) were unaware of their HIV-infected status and this proportion varied from an estimated 19% of HIV-infected MSM, to 25% of HIV-infected people who inject drugs, and 35% of HIV-infected heterosexuals. An estimated 3,300 new infections occurred in Canada in 2008, which was about the same as the estimate of 3,200 in 2005. Of those new infections, 26% were among women and 12.5% were of Aboriginal descent; in terms of exposure category, MSM continued to comprise the greatest proportion of new infections (44%) and heterosexuals who originated in countries where HIV is endemic comprised 16%.
Conclusion: HIV incidence in Canada is not decreasing. Aboriginal people and people from HIV-endemic countries continue to be over-represented in Canada’s HIV epidemic. People unaware of their HIV infection are a priority for being tested and diagnosed to enable them to take advantage of care services and receive counselling to prevent further spread of HIV.
Key words: HIV, prevalence, incidence
Résumé
Objectif: Estimer le nombre d’infections à VIH prévalentes et incidentes au Canada en 2008.
Méthode: Nous avons estimé la prévalence et l’incidence nationales du VIH au Canada par la méthode des cahiers, deux méthodes de modélisation statistique et un modèle itératif sur feuille de calcul électronique.
Résultats: Le nombre estimatif de personnes vivant avec une infection à VIH diagnostiquée ou non diagnostiquée (y compris le sida) continue d’augmenter. Il est passé d’environ 57 000 en 2005 à 65 000 en 2008. Près de la moitié (48 %) de ces personnes infectées par le VIH étaient des hommes ayant des relations sexuelles avec des hommes (HRSH), et 22 % étaient des femmes. Environ 16 900 personnes ayant une infection prévalente (soit 26 % de cette population) ignoraient qu’elles étaient infectées. Cette proportion variait: elle était d’environ 19 % chez les HRSH, de 25 % chez les utilisateurs de drogues injectables et de 35 % chez les hétérosexuels. Il y a eu quelque 3 300 nouveaux cas d’infection au Canada en 2008, environ le même nombre qu’en 2005 (3 200 selon les estimations). Sur ces nouveaux cas d’infection, 26 % étaient des femmes et 12,5 % étaient des personnes d’ascendance autochtone; du point de vue du risque, les HRSH représentaient encore la plus grande proportion des nouveaux cas d’infection (44 %), et les hétérosexuels venant de pays où le VIH est endémique représentaient 16 % des cas.
Conclusion: L’incidence du VIH au Canada ne diminue pas. Les Autochtones et les ressortissants de pays où le VIH est endémique sont encore surreprésentés dans l’épidémie de VIH au Canada. Les personnes qui ignorent qu’elles sont infectées par le VIH devraient être testées et diagnostiquées en priorité pour qu’elles puissent recevoir les soins et les conseils nécessaires pour prévenir la propagation du virus.
Mots clés: VIH, prévalence, incidence
Footnotes
Acknowledgements: The authors acknowledge the contribution of provincial public health officials, HIV researchers and community representatives for their support and collaboration in producing these estimates. We thank the provincial and territorial HIV/AIDS coordinators, laboratories, health care providers, and reporting physicians for providing HIV and AIDS surveillance data. The authors are grateful to Susanna Ogunnaike-Cooke, Kristina Lalonde, Marissa McGuire and Jill Tarasuk of CCDIC, PHAC, for providing data in support of the estimates. In addition, we thank Jessica Halverson of CCDIC, PHAC, for providing constructive comments on the draft manuscript.
Conflict of Interest: None to declare.
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