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  • The cascade of care is the flow of people through a health system from testing to viral suppression
  • Countries and regions are encouraged to help HIV-positive people achieve viral suppression
  • A study from Manitoba has found many improvements in the province’s cascade of care, but gaps remain

Initiating and continuing to take antiretroviral therapy (ART) can help suppress the amount of HIV in the blood to very low levels commonly referred to as undetectable. Continued use of ART exactly as directed helps keep HIV levels suppressed. This ultimately results in improved measures of health and a significantly reduced risk of AIDS-related complications. Studies project that many ART users will have near-normal life expectancy. Another benefit of ART is that people who achieve and maintain an undetectable viral load do not pass on HIV to their sexual partners.

These personal and societal benefits of ART are so significant that the joint United Nations Programme on AIDS/HIV (UNAIDS) encourages cities, regions and countries to help their HIV-positive population move through the cascade of care to achieve viral suppression. UNAIDS encapsulates this goal through the phrase “95-95-95,” meaning that cities, regions and countries should reach the following goals by 2025:

  • 95% of people with HIV are aware of their infection status
  • 95% of people who are aware of their HIV infection status have initiated ART
  • 95% of people who have initiated ART have achieved viral suppression


For societies to help HIV-positive people reach these goals, more investment and attention to health systems will be required. At each important step or milestone in the flow of people across the care continuum (the cascade of care), people can fall out and fail to reach the next step because of barriers. Understanding the flow of people through health systems is useful because it can help researchers and health policy planners find gaps in the cascade. Interventions can then be crafted to help overcome barriers and move to the next step in the cascade, with the end goal being viral suppression.

In Manitoba

Researchers in Manitoba have been studying the HIV cascade of care in a large group of patients. They found that some people encountered barriers to progressing through the cascade. These barriers were associated with race/ethnicity, substance use, age and geography. This study is a good first step toward understanding inequalities in the cascade of care in this province. The results could serve as the impetus for different studies to better understand why some people face barriers in the cascade of care. Such an understanding could lead to policy interventions to improve the care for all HIV-positive people in Manitoba and possibly other parts of Canada.

Study details

Researchers accessed different databases that provided information about the following:

  • doctor visits
  • hospitalization
  • provision of prescription medicines
  • use of lab testing services

As with all database studies on the cascade of care in Canada involving HIV-positive people, the Manitoba researchers took care to not collect the names of participants as they did their work.

The researchers analyzed data on 703 participants to the end of 2017. They defined the different steps in the cascade of care in the following way:

  • alive and diagnosed with HIV
  • in care (visited a doctor and had some laboratory monitoring)
  • retained in care (continued to have additional lab and/or doctor visits)
  • on treatment (medications were dispensed at least twice, three months apart)
  • virally suppressed (in this case, having a viral load less than 200 copies/mL)


The distribution of the 703 participants across the cascade was as follows:

  • alive and diagnosed – 100% (703 people)
  • in care – 91% (638 people)
  • retained in care – 86% (606 people)
  • on treatment – 82% (573 people)
  • virally suppressed – 74% (523 people)

Gaps in the flow of people

Analysis of the data suggested that some people in certain subgroups encountered barriers to movement through the cascade. These subgroups were as follows:

  • Black and Indigenous people (compared to white participants)
  • people with a history of using street drugs (compared to people who did not use drugs)
  • younger people, aged 18 to 29 (compared to older people)
  • people who lived outside of Winnipeg, particularly in northern, southern and western regions of Manitoba

Bear in mind

The Manitoba study did not monitor every HIV-positive person in the province. However, the researchers noted that “previous work suggests that [the] data are reasonably representative of the larger population in HIV care in Manitoba.”

Based on the analysis by the researchers, the health system in Manitoba is helping HIV-positive people make progress toward achieving viral suppression. However, as with many other regions and countries, there is room for improvement.

The cascade research done by the scientists in Manitoba can serve as a springboard to conduct additional research to find out what barriers people encounter and to ultimately develop policies to help remove those barriers. This additional research may require interviews, focus groups and working with community partners.

—Sean R. Hosein


Canada’s progress on 90-90-90 – CATIE

Estimates of HIV incidence, prevalence and Canada’s progress on meeting the 90-90-90 HIV targets – Public Health Agency of Canada

2025 Aids targets -- UNAIDS

Objectifs 2020 : des avancées disparates. Le rapport de l’ONUSIDA sur l’épidémie mondiale de sida fait état d’un échec accentué par la COVID-19 – UNAIDS


  1. McClarty LM, Blanchard JF, Becker ML. Leaving no one behind? An equity analysis of the HIV care cascade among a cohort of people living with HIV in Manitoba, Canada. BMC Public Health. 2021 Feb 4;21(1):281.
  2. McClarty LM, Kasper K, Ireland L, et al. The HIV care cascade in Manitoba, Canada: Methods, measures and estimates to meet local needs. Journal of Clinical Epidemiology. 2021 Apr;132:26-33.
  3. Samji H, Cescon A, Hogg RS, et al. Closing the gap: increases in life expectancy among treated HIV-positive individuals in the United States and Canada. PLoS One. 2013 Dec 18;8(12):e81355.