July 31, 2006

Statement

News Release
	Report Provides Insight into HIV/AIDS Epidemic in Canada
Backgrounders
	The State of the HIV/AIDS Epidemic in Canada
	Government of Canada's Domestic HIV/AIDS Role
	Estimates of the number of people living with HIV in Canada, 2005

Estimates of the number of people living with HIV in Canada, 2005

Background

As a means of monitoring the HIV epidemic and assessing the effectiveness of prevention efforts, estimates of the number of people living with HIV are made around the world. The Public Health Agency of Canada's (PHAC) Centre for Infectious Disease Prevention and Control (CIDPC) produces two types of estimates as part of its mandate to monitor HIV/AIDS trends in Canada: prevalence, or the number of people living with HIV (including AIDS), and incidence, the number of new infections in a one-year period. These estimates guide the work done by PHAC and other federal departments under the Federal Initiative to Address HIV/AIDS in Canada.

HIV and AIDS surveillance data do not include individuals who are untested and undiagnosed. Since surveillance data can therefore only describe the diagnosed portion of the epidemic, modelling and additional sources of information are required to describe the epidemic among both diagnosed and undiagnosed Canadians. The methods used to estimate HIV prevalence and incidence at the national level bring together all available data and are described in more detail in the reference given at the end of the document.

This document summarizes the 2005 HIV estimates for Canada.

Estimates of People Living with HIV at the end of 2005

At the end of 2005, an estimated 58,000 people in Canada were living with HIV infection (including AIDS). This represents an increase of about 16% from the 2002 estimate of 50,000 (Table 1). The individuals most affected by the epidemic have been grouped by their HIV exposure category. These include: men who have sex with men (MSM); injecting drug users (IDU); individuals having heterosexual contact with a person who is either HIV-infected or at risk for HIV, or having heterosexual activity as the only identified risk for HIV (Heterosexual/non-endemic); individuals with an origin in a country where HIV is endemic (mainly sub-Saharan Africa and the Caribbean) and not identified as MSM or IDU (Heterosexual/endemic); and recipients of blood transfusion or clotting factor, perinatal and occupational transmission (Other).

At 51%, the men who have sex with men exposure category continues to account for the majority of individuals living with HIV infection in Canada. In comparison, the injecting drug user category accounted for 17%, the heterosexual/non-endemic category accounted for 15%, and the heterosexual/ endemic exposure category accounted for 12% (Figure 1).

Figure 1 : Distribution of the estimated number of people living with HIV infection (including AIDS) in Canada at the end of 2005 by exposure category

Estimates of New Infections in 2005

The number of new HIV infections in Canada in 2005 has not decreased and may have increased slightly compared to 2002. An estimated 2,300 to 4,500 new HIV infections occurred in 2005 compared with 2,100 to 4,000 in 2002 (Table 2).

At 45%, the men who have sex with men exposure category continues to account for the greatest portion of new infections (Figure 2). Injecting drug users accounted for 14% of these new infections, while the heterosexual/ non-endemic category accounted for 21% and the heterosexual/ endemic category accounted for 16%.

Persons from HIV-endemic countries continue to be over-represented in Canada's HIV epidemic. While they comprise only 1.5% of the Canadian population, their estimated infection rate is almost 13 times higher than among other Canadians.

Figure 2 : Distribution of the estimated number of new HIV infections in Canada in 2005 by exposure category.

Women

It was estimated that women account for 20% of people living with HIV infection in Canada at the end of 2005. Women were also estimated to account for 27% of all new infections in 2005. Approximately three quarters of the new infections among women were attributed to the heterosexual exposure category (endemic and non-endemic together) and the remainder was attributed to the injecting drug user exposure category.

Aboriginal Canadians

Aboriginal persons continue to be over-represented in the HIV epidemic in Canada. They were estimated to account for 7.5% of persons living with HIV in Canada at the end of 2005 and 9% of all new HIV infections in 2005. This shows an estimated overall infection rate in Aboriginal persons that is nearly 3 times higher than among non-Aboriginals.

At 53%, injecting drug users accounted for a majority of new infections among Aboriginal persons. The heterosexual exposure category accounted for 33% and the men who have sex with men category for 10%. This distribution is quite different from that seen in the wider group of all newly HIV infected Canadians in 2005 (see Figure 2).

Undiagnosed

At the end of 2005, an estimated 27% of the 58,000 individuals living with HIV were unaware of their infection. That makes this group “hidden” to the health care and disease monitoring systems, and so they cannot take advantage of available treatment strategies or appropriate counselling to prevent the further spread of HIV.

Comment

The number of Canadians living with HIV infection will likely continue to increase in the years to come as new infections continue and survival rates improve. This will mean increased future care requirements.

Aboriginal people and persons from HIV-endemic countries continue to be over-represented in Canada's HIV epidemic, highlighting the need for specific measures to address the unique aspects of certain groups. Injecting drug users is the main HIV exposure category among Aboriginal persons while heterosexual activity is the main risk for women and persons from HIV-endemic countries.

There continues to be a sizeable number of people unaware of their HIV infection. Until these individuals are tested and diagnosed, they cannot take advantage of appropriate care and treatment services, nor can they receive counselling to prevent further spread of HIV.

To successfully control the HIV epidemic in Canada, more effective strategies are needed to prevent new infections and provide services for all of the vulnerable populations identified in the Federal Initiative to Address HIV/AIDS in Canada.

Reference

Boulos D, Yan P, Schanzer D, Remis RS and Archibald CP. Estimates of HIV prevalence and incidence in Canada, 2005. Canada Communicable Disease Report 2006; 32(15) (in press). Will be available at the following website on August 8, 2006:
http://www.phac-aspc.gc.ca/publicat/ccdr-rmtc/06vol32/dr3215e.html