Prevention in Focus

Spring 2012 

The STOP HIV/AIDS project: Treatment as prevention in the real world

By Christie Johnston

British Columbia’s STOP HIV/AIDS pilot project has sparked media interest and dialogue in Canada and internationally.1,2,3,4 It represents a new approach to HIV prevention and treatment. But what is the STOP HIV/AIDS project? What are some of its strengths and why is it controversial?

Treatment as prevention: From theory to practice

Seek and Treat for Optimal Prevention of HIV/AIDS (STOP HIV/AIDS) is one of the first projects in the world that formally attempts to put the science behind “treatment as prevention” into practice: If more people living with HIV in a community are on effective anti-HIV treatment, the “community viral load” will be lowered, resulting in fewer new HIV infections. This hypothesis is based on science showing that if a person living with HIV is treated for HIV effectively, their viral load will be reduced, thereby reducing the likelihood of HIV transmission to others. If the community viral load could be decreased enough, this could fundamentally alter the HIV epidemic.

Since researcher and director of the BC Centre for Excellence Julio Montaner and his team proposed this hypothesis at the 2006 International AIDS Conference in Toronto, evidence on the effectiveness of HIV treatment as a prevention method has become stronger, with support from observational studies,5,6 a randomized controlled trial7 and modelling studies.8

As evidence has increased to support this hypothesis, there has been a growing realization that treatment as prevention might emerge as a key strategy in the global effort to address HIV. Many global leaders in HIV prevention have endorsed the science behind the theory, and pilot research projects, such as STOP, are underway to test the hypothesis.2,3,9 Given this real potential, we need to understand not only the science but also the real-world experience of the STOP project, as one of the first attempts to implement a large-scale combination HIV prevention and treatment program.

For more current information, please see HIV treatment and an undetectable viral load to prevent HIV transmission.


STOP HIV/AIDS is a four-year pilot project with $48 million of funding from the government of British Columbia. This project aims to increase the quality of life for people living with HIV and to reduce the number of new HIV infections by taking a proactive public health approach to finding people living with HIV, bringing them into HIV treatment programs and supporting them to stay on treatment.4,10

STOP, which is being rolled out in Vancouver and Prince George, is made up of numerous interconnected and discrete community-based, clinic-based and policy-focused programs implemented through the collaboration of an impressive number of stakeholders. Key partners include the British Columbia Ministry of Health Services, the B.C. Centre for Excellence in HIV/AIDS, Providence Health Care, and three health authorities: Vancouver Coastal Health, Northern Health and Provincial Health Services Authority. To ensure that individuals in Vancouver are provided with the most comprehensive care possible, Vancouver Coastal Health and Providence Health Care have joined forces to become the “Vancouver STOP HIV/AIDS Project”. This means that they work collaboratively and co-lead the implementation of STOP in this city.

Representatives from these organizations, along with representatives from some First Nations communities in the province and the HIV “community” in Vancouver and northern B.C., make up the Leadership Committee, a group that is ultimately responsible for the implementation of the project.

These partners play different roles in the project. The B.C. Ministry of Health Services is the funding organization, the B.C. Centre for Excellence is responsible for research and the overall evaluation of STOP goals, and the Vancouver STOP Project players, Northern Health and the Provincial Health Services Authority are responsible for implementation “on the ground,” either through the creation of their own programs or through the funding of external projects.

The input of B.C. community organizations and individuals living with HIV is critical to the success of the STOP project; many of the programs that contribute to its overall goals are implemented by community-based organizations.

STOP implementation: Is this all about “seeking” and “treating”?

Treatment as prevention is sometimes referred to as “seek and treat”: “seek” meaning outreach and testing to increase the number of people who know they are HIV positive, and “treat” meaning putting people on treatment when clinically warranted and when people are ready to start. But treatment as prevention programs need to be far more complex than merely “seeking” and “treating.” Treatment as prevention programs must be implemented through a rights-based framework and address individual and community needs across the full continuum of care, which not only includes “seeking” and “treating” but also prevention, care and support.11

The implementation of STOP reflects this continuum of care model: the multiple and diverse projects implemented through STOP HIV/AIDS work across different sites and sectors, and at different stages of HIV prevention, treatment, care and support.

STOP activities can be categorized under four headings:

  1. Seek: Find and test more people for HIV, particularly those at highest risk.
  2. Link: Connect people who are living with HIV with care and support services.
  3. Treat: Get more HIV-positive people on treatment and treat them earlier (abiding by treatment guidelines).
  4. Retain: Support people to stay on treatment and fully adhere to their meds.

By effectively implementing activities within these four areas in multiple settings and by ensuring collaboration across all stakeholder groups, STOP could have a significant effect on the lives of individuals living with HIV and the number of new HIV infections.

Examples of programs

The complexity of a treatment as prevention initiative such as STOP is apparent in the number and diversity of local programs and policies that are being developed, evaluated and adapted at a very fast pace. For example, new programs that are funded through the Vancouver STOP Project are evaluated at six-month intervals—if a program does not prove to be effective in that time, it may be abandoned while another program is developed and tested. Upwards of 41 pilot programs have been funded by the Vancouver STOP Project. Through this process of experimentation and evaluation, the aim is to find the right case mix of programs and services that will meet the goals of STOP.

Several programs have recently been implemented by STOP through Vancouver STOP Project and Northern Health, among others. These reflect the diversity of programs that may need to be incorporated into a successful treatment as prevention initiative. They include the following:


  • Expanded HIV testing in hospitals. Physicians began offering confidential HIV tests to every patient requiring blood work admitted to four Vancouver hospitals. Informed consent is required. The goal of this program is to increase the number of people who are aware of their HIV status.


  • Enhancement of a peer-led program. Positive Living BC, a member-run community-based organization, developed Peer Navigators, a peer-led program that provides support to people living with HIV. One goal of this program is to link people living with HIV to, and help them navigate through, programs and services that might be useful to them.


  • Expanded access to pharmacists with HIV expertise. Northern Health hired a full-time HIV pharmacist to enhance access to HIV treatment in northern B.C. Prior to this, prescribing physicians would have to order HIV medications from pharmacists in Vancouver, sometimes significantly delaying people’s access to HIV medication. 


  • Creation of more housing units for people living with HIV. Twenty-five new affordable housing units became available to people living with HIV who face barriers to engaging in HIV treatment and care through Coast Mental Health. Providing affordable housing for people living with HIV who are either homeless or at risk for homelessness ensures a more stable environment, which should help to retain them in care.

Strengths and controversy with implementation of STOP

STOP has already proven to be a catalyst for enhanced, positive collaboration among diverse B.C. stakeholder groups, as suggested by three key players: Chris Buchner (VCH), Ross Harvey (Positive Living BC) and Sam Milligan (Central Interior Northern Health Services). STOP is also seen by some as an opportunity to change course in our response to the HIV epidemic in Canada. As Chris Buchner (VCH) and Wayne Robert (Health Initiative for Men) have suggested, with this new funding, groups can try exciting new things and make a significant impact on the epidemic and the lives of people living with HIV.

However, Evin Jones, the executive director of the Pacific AIDS Network (PAN) points out that concerns have also been raised by PAN’s member agencies that treatment as prevention projects, such as STOP, could lead to the “re-medicalization of HIV,” meaning that HIV and related issues and behaviours may be defined purely in terms of health/illness and treated only through medical means. Related to this is a concern that the role community-based agencies play may shrink as a result.

More specific concerns related to STOP have focused on the evaluation of the project (what is being measured to determine “success”) and the sustainability of the programs implemented with STOP funds, given that the project is a pilot. Further, some have raised concerns about the process of implementation to date, which in some cases has been less integrated across policy and program sectors. The pace at which STOP has been rolled out is impressive, but this pace may lead to challenges for program delivery on the ground.

STOP HIV/AIDS: A new way forward

While we do not yet know the long-term implications of the STOP HIV/AIDS project on the community-based response to HIV in B.C. or in the rest of Canada, we do know that the science behind treatment as prevention may increasingly challenge communities to take on this new approach. To ensure that HIV-related organizations and people living with HIV continue to play a major role in the response, we must not only understand the science, but also the successes of those who have tested this hypothesis. It is critical that we also anticipate and understand the ethical, programmatic and evaluative challenges related to the implementation of this new model.

For a more comprehensive discussion of the STOP HIV/AIDS pilot project, see Views from the front lines.


  • 1. Adam B. Epistemic fault lines in biomedical and social approaches to HIV prevention. Journal of the International AIDS Society. 2011;14(Suppl 2):S2.
  • 2. a. b. British Columbia Centre for Excellence in HIV/AIDS. U.S. Secretary of State Hillary Clinton endorses the made-in-BC strategy of treatment as prevention [Internet]. Vancouver: The Centre, St. Paul’s Hospital; 2011 Nov 8 [cited 2011 Nov 25]. Available from:
  • 3. a. b. CBC News. China chooses AIDS control model from B.C. [Internet]. CBC; 2011 Feb 24 [cited 2011 Nov 25]. Available from:
  • 4. a. b. STOP HIV/AIDS Pilot Project [Internet]. STOP HIV/AIDS: Seek and Treat for Optimal Prevention of HIV/AIDS [cited 2011 Nov 25]. Available from:
  • 5. Anglemyer A, Rutherford GW, Baggaley RC et al. Antiretroviral therapy for prevention of HIV transmission in HIV-discordant couples. Cochrane Database of Systematic Reviews. 2011;(8):CD009153.
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  • 8. Granich RM, Gilks CF, Dye C et al. Universal voluntary HIV testing with immediate antiretroviral therapy as a strategy for elimination of HIV: a mathematical model. The Lancet. 2009 Jan 3;373(9657):48-57.
  • 9. World Health Organization [Internet]. The treatment 2.0 framework for action: catalysing the next phase of treatment, care and support. 2011[cited 2011 Nov 25]. Available from:
  • 10. Montaner JS, Hogg R, Wood E et al. The case for expanding access to highly active antiretroviral therapy to curb the growth of the HIV epidemic. The Lancet. 5;368(9534):531-6.
  • 11. Williams B, Wood R, Dukay V et al. Treatment as prevention: preparing the way. Journal of the International AIDS Society. 2011;14 Suppl 1:S6.

About the author(s)

Christie Johnston is the Manager of Community Prevention Programs at CATIE. She holds a Masters degree in Anthropology and International Relations. Before joining CATIE, Christie worked on a number of community-based research and knowledge exchange projects at the Ontario HIV Treatment Network (OHTN), AIDS Committee of Toronto (ACT) and abroad, and acted as Volunteer Program Coordinator for the AIDS 2006 Local Host Secretariat.

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