HIV in Canada: A primer for service providers

 

The HIV treatment cascade

Key Points

  • The treatment cascade reflects the different services someone with HIV needs to achieve optimal health outcomes.
  • The treatment cascade is based on the successive steps that are needed for a person with HIV to achieve an undetectable viral load.

The treatment cascade reflects the different services someone with HIV needs to achieve optimal health outcomes, including HIV testing and diagnosis, linkage to appropriate medical care (and other health services), support while in care, access to HIV treatment if and when the individual is ready, and support on treatment. While enhanced engagement in the cascade may have a secondary benefit of reducing HIV transmission, the HIV treatment cascade does not include services for people who are HIV negative (e.g., prevention services); these services are an additional component of an integrated framework.

The HIV treatment cascade is a convenient tool for assessing integrated health service delivery for people with HIV. It is based on the successive steps that are needed for a person with HIV to achieve an undetectable viral load. Research shows that people with HIV who have an undetectable viral load are more likely to live long, healthy lives and are less likely to pass HIV to others. Starting from the total number of people with HIV in a specific region (both diagnosed and undiagnosed), the successive indicators in the stages of engagement in the HIV treatment cascade are:

  • total number of people with HIV
  • number of people diagnosed with HIV
  • number of people linked to HIV care
  • number of people retained in care
  • number of people on HIV treatment
  • number of people with undetectable viral load

At each stage of the cascade people may be lost to engagement and care as a result of many types of barriers, such as poor access to services; stigma and discrimination; poverty, food security and homelessness; and mental health and addictions issues. Typically only a small proportion of people with HIV are engaged in all the steps needed to achieve an undetectable viral load.

In a strategic discussion paper released in 2014, UNAIDS used the HIV treatment cascade to propose that by 2020:

  • 90% of all people with HIV will know their status;
  • 90% of all people with diagnosed HIV infection will receive sustained ART;
  • 90% of all people receiving ART will have viral suppression (undetectable viral load).

The strategy is informally known as “90-90-90”, and if these targets are achieved, 81% of all people living with HIV will be on treatment and 73% will have an undetectable viral load – the key indicator of ongoing successful treatment – and, therefore, be significantly less likely to transmit the virus to others.” Modelling studies show that achieving these targets would result in the end of the AIDS epidemic by 2030.

In 2015, Canada endorsed the 90-90-90 targets. New 2016 estimates of the HIV treatment cascade in Canada were released in 2018. It is estimated that in 2016, 86% of people with HIV were diagnosed, 81% of people diagnosed were on treatment, and 91% of people on treatment had an undetectable viral load. This means that, overall, an estimated 63% of people with HIV in Canada had an undetectable viral load in 2016.

Resources

Canada makes some progress on HIV but much work lies aheadCATIE News

The HIV treatment cascade – patching the leaks to improve HIV prevention – Prevention in Focus

Changing the narrative: Why HIV prevention in Canada needs to embrace HIV treatment –Prevention in Focus

90-90-90—An ambitious treatment target to help end the AIDS epidemic UNAIDS

Summary: Estimates of HIV Incidence, Prevalence and Canada’s Progress on Meeting the 90-90-90 HIV targets, 2016 – Public Health Agency of Canada

HIV in Canada – Public Health Agency of Canada

The Engagement CascadeThe Positive Side

 

Sources

  1. Hull MW, Wu Z, Montaner JSG. Optimizing the engagement of care cascade. Current Opinion in HIV and AIDS. 2012 Nov;7(6):579–586.
  2. Gardner EM, McLees MP, Steiner JF, et al. The spectrum of engagement in HIV care and its relevance to test-and-treat strategies for prevention of HIV infection. Clinical Infectious Diseases. 2011 Mar 1;52(6):793–800.
  3. Vital signs: HIV prevention through care and treatment--United States. Morbidity and Mortality Weekly Report. 2011 Dec 2;60(47):1618–1623.
  4. Wilton J. The HIV treatment cascade – patching the leaks to improve HIV prevention. Prevention in Focus. CATIE, Spring 2013. Available from: http://www.catie.ca/en/pif/spring-2013/hiv-treatment-cascade-patching-leaks-improve-hiv-prevention.
  5. UNAIDS. 90-90-90: An ambitious treatment target to help end the AIDS epidemic. 2014. Available from: http://www.unaids.org/sites/default/files/media_asset/90-90-90_en_0.pdf
  6. Public Health Agency of Canada. Summary: Estimates of HIV Incidence, Prevalence and Canada’s Progress on Meeting the 90-90-90 HIV targets, 2016. Public Health Agency of Canada, 2018. Available from: https://www.canada.ca/en/public-health/services/publications/diseases-conditions/summary-estimates-hiv-incidence-prevalence-canadas-progress-90-90-90.html
  7. UNAIDS. Ending AIDS: Progress Towards 90-90-90. 2017. Available at: http://www.unaids.org/en/resources/documents/2017/20170720_Global_AIDS_update_2017