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The Ontario HIV Epidemiology
and Surveillance Initiative

Download the OHESI fact sheet in PDF format.

OHESI is a new provincial collaboration between agencies involved with HIV epidemiology and surveillance in Ontario.

The overall purpose of this new initiative is to contribute to achieving the vision, mission and goals of “Changing the Course of the HIV Prevention, Engagement and Care Cascade in Ontario HIV/AIDS Strategy to 2026.” In support of the strategy, the objectives of the OHESI are to understand, monitor and translate the epidemiology of HIV in the province of Ontario, in order to:

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    Understand the challenges along the prevention, engagement and care cascade.

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    Inform local and provincial policies and programs such that services can adjust to meet changing needs.

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    Provide the information needed to develop, implement and evaluate strategies and interventions, and integrate evidence into practice.

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    Monitor the provincial progress in achieving the goals of the strategy.

Who’s involved?

Why was OHESI created?

By working together, the agencies involved with OHESI are aiming to achieve better access to timely, relevant, and comprehensive information about the epidemiology of HIV in Ontario, and to disseminate this information more widely to the different groups of stakeholders who need to know it, including:

  • General public
  • People living with or at risk of HIV
  • AIDS Service Organizations and funded programs
  • Public health units and community health centres
  • Clinicians, clinics and other service providers delivering care for people with HIV
  • Researchers
  • Policy and decision makers
  • Local Health Integration Networks

How will OHESI do this?

OHESI’s activities will reflect the conceptual frameworks of the provincial strategy, namely syndemic theory and the integrated HIV prevention, engagement and care cascade. Using HIV epidemiology and surveillance data related to these frameworks, the primary emphasis of OHESI will be on the following populations affected by HIV in Ontario:

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    People living with HIV/AIDS

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    Gay, bisexual and other men who have sex with men, including trans men

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    African, Caribbean and Black communities, including people from HIV-endemic countries

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    Indigenous people

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    People who use drugs

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    At-risk women, including trans women

For example, this may include for a given population:

1. Drawing on HIV testing and viral load data to describe testing uptake, diagnosis, linkage, retention in care and suppressed viral load
2. Presenting alongside research data which looks at underlying determinants (e.g. behavioural measures, socioeconomic status)
3. Combining these with modeled estimates of HIV incidence and prevalence


For more information contact Abigail Kroch, Applied Epidemiology Unit, Ontario HIV Treatment Network:

416-642-6486, ext. 2306

akroch [at] ohtn.on.ca /
ohesi [at] ohtn.on.ca

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