HIV in Canada: A primer for service providers

Canadian Epidemiology of HIV

HIV epidemiologic information is used to develop evidence-based prevention and control programs and to promote the most effective use of health resources. The Public Health Agency of Canada (PHAC) monitors the HIV epidemic in Canada. PHAC produces estimates of HIV prevalence and incidence and surveillance reports on diagnosed (reported) HIV and AIDS cases.

PHAC reports the number of HIV diagnoses reported to the agency by each province (known as “reported cases”). Information contained in the reported cases provides a useful description of the characteristics of people diagnosed with HIV or AIDS in Canada. However, surveillance data understate the magnitude of the HIV epidemic because such data are subject to reporting delays, under-reporting and changing patterns in HIV testing behaviours (who comes forward for testing); surveillance data also do not include individuals who remain untested and undiagnosed.

National HIV estimates are produced by PHAC and published every three years. PHAC estimates HIV prevalence and incidence using statistical methods that take into account some of the limitations of surveillance data (number of HIV diagnoses reported to PHAC) and also account for the number of people living with HIV who do not yet know they have it. Statistical modelling, using surveillance data and additional sources of information, allows PHAC to produce HIV estimates among those diagnosed and undiagnosed. The most recent estimates available are for 2014. The next set of estimates will be available in 2018 and will pertain to the year 2017. PHAC’s estimates are used when available in HIV in Canada; however, it should be noted that estimates are not available for certain populations. In these instances, surveillance data is used (diagnoses).

PHAC also supports a federal initiative involving five second-generation surveillance systems for specific groups: men who have sex with men (M-Track), injection drug users (I-Track), Indigenous people (A-Track), people from countries where HIV is endemic (E-Track) and people living with HIV (P-Track). The five surveillance systems are in various stages of completion, from development through to implementation. Methods involve the periodic administration of cross-sectional surveys and may include the collection of dried blood spots or saliva for testing (HIV, hepatitis C, sexually transmitted infections) at selected sites across Canada. These surveillance systems allow for the monitoring of the prevalence of and trends in HIV risk behaviours, the prevalence of and trends in HIV testing, the use of HIV prevention services, and trends in the prevalence of HIV and other infections. When available, these data are used in HIV in Canada to supplement information on HIV estimates and diagnosed cases of HIV.


The epidemiology of HIV in Canada – CATIE Fact sheet

Summary: Estimates of HIV Incidence, Prevalence and Proportion Undiagnosed in Canada, 2014 – Public Health Agency of Canada


  1. Public Health Agency of Canada. Summary: Estimates of HIV Incidence, Prevalence and Proportion Undiagnosed in Canada, 2014. Surveillance and Epidemiology Division, Professional Guidelines and Public Health Practice Division, Centre for Communicable Diseases and Infection Control, Public Health Agency of Canada, 2015. Available at:
  2. Public Health Agency of Canada. HIV and AIDS in Canada: Surveillance Report to December 31, 2014. Minister of Public Works and Government Services Canada; 2015. Available at: