The Ontario HIV Epidemiology and Surveillance Initiative (OHESI) is a collaboration involving the HIV and Hepatitis C Programs of the Ontario Ministry of Health (MOH), Public Health Ontario (PHO), the Public Health Agency of Canada (PHAC), and the Ontario HIV Treatment Network (OHTN) Applied Epidemiology Unit (AEU).

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Why was OHESI created?

The objectives of OHESI are to analyze, monitor and disseminate knowledge products on the epidemiology of HIV in Ontario. OHESI is a vital partnership that supports Ontario’s ongoing ability to assess the impact of policy directions and HIV related program initiatives. 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


Policy and decision makers

Health services organizations

The success of the partnership would not be possible without the strategic, technical and resource contributions of all the partners. OHESI also receives ongoing advice from a community advisory committee: people working in the community-based HIV service sector and HIV clinics whose input helps ensure that OHESI reports and other products support collective efforts and impact in neighborhoods, communities and organizations across the province.

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:

People living with HIV/AIDS

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

African, Caribbean and Black people

Indigenous Peoples

People who use drugs

Women who face systemic risks, 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

Who’s involved

Contact Us For More Information

[email protected]

Abigail Kroch, Senior Director, Science, Ontario HIV Treatment Network
(416) 642-6486 extension 2306