HIV in Canada: A primer for service providers


HIV Treatment

Key Points

  • HIV treatment improves the long-term health of a person with HIV and significantly reduces the risk of HIV transmission.
  • Newer HIV drugs are safer, simpler and more effective than those available when HIV treatment was first introduced.
  • Starting treatment early is beneficial for long-term health outcomes.
  • With proper treatment and care, most people with HIV can stay healthy and live a long, full life.

When combinations of powerful new drugs for antiretroviral therapy (ART) became available in the mid-1990s, HIV treatment was revolutionized. There was a drastic reduction in the number of illnesses experienced by people with HIV and increased survival. ART allowed many people with HIV to return to work and lead a full life.

Newer HIV treatments are safer, simpler and more effective than those available when ART was first introduced. The power of ART today is so profound that a young HIV-positive adult who begins treatment shortly after diagnosis, who takes his/her medicines every day exactly as directed and who has no or few co-existing health conditions is expected to live a near-normal lifespan. Evidence also shows that HIV-positive people who are on ART, engaged in care, and have an ongoing undetectable viral load are substantially less likely to transmit HIV to others, be it through sex, when sharing equipment to use drugs, or during pregnancy and birth. In fact, the evidence for sexual transmission shows that people on ART who maintain an undetectable viral load do not pass HIV to their sexual partners.

The goal of ART is to greatly reduce the replication of HIV and reduce the amount of HIV in the body. This can only happen if someone is adherent to their treatment. A blood test, called the HIV viral load test, is used to monitor how well treatment is working. Ideally, ART will reduce the viral load to an undetectable level and it will remain undetectable indefinitely. However, an undetectable viral load does not mean that there is no HIV present. HIV is still present at low levels in the blood and in other viral reservoirs in the body.

A sustained increase in viral load may indicate that the treatment is no longer working and/or that the individual is having difficulties adhering to the treatment protocol. The cause of the increase needs to be investigated to determine if the treatment should be changed and/or adherence support is required. The treatment regimen may also need to be changed if any side effects are intolerable or if there are drug interactions with other drugs the individual is taking.

Effective ART consists of a combination of drugs from at least two drug classes (or groups). There are currently six classes of approved HIV drugs:

  • nucleoside and nucleotide reverse transcriptase inhibitors (NRTIs and NtRTIs; or simply “nukes”)
  • non-nucleoside reverse transcriptase inhibitors (NNRTIs or “non-nukes”)
  • protease inhibitors
  • fusion inhibitor
  • CCR5 co-receptor antagonists
  • integrase inhibitors

For many years there was uncertainty as to the best time to start treatment. We now know from a large study, called the START trial, that people with HIV should start treatment as soon as possible after their diagnosis. Since these findings were announced, treatment guidelines from the World Health Organization and countries such as the United States and the UK have been updated to recommend that HIV treatment be offered immediately to all people diagnosed with HIV. The Association of Medical Microbiology and Infectious Disease Canada (AMMI) states in a position statement:

“AMMI Canada lends its support to the recommendation for early initiation of ART in Canada based on the individual, as well as potential public health benefits.”

Because HIV treatment can be complex and lifelong, many people with HIV can benefit from additional care and support services. This may include support for starting treatment, adherence support, support for managing side effects of treatment, or support to navigate healthcare systems. It may also include support for issues that may indirectly affect the ability of people with HIV to take treatment, such as stable housing, food security or mental health challenges.


HIV Treatments

Detailed results from the START studyTreatmentUpdate 210 (August/September 2015)

Your Guide to HIV Treatment

The re-emergence of dual therapyTreatmentUpdate 224 (January 2018)

Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents – Department of Health and Human Services

Antiretroviral Drugs for Treatment and Prevention of HIV Infection in Adults: 2018 Recommendations of the International Antiviral Society–USA Panel

Guidelines: clinical management and treatment of HIV infected adults in Europe – European AIDS Clinical Society

La thérapie antirétrovirale pour les adultes infectés par le VIH : Guide pour les professionnels de la santé du Québec – Ministère de la Santé et des Services sociaux du Québec

AMMI Canada position statement: The use of early antiretroviral therapy in HIV-infected persons

CATIE statement on the use of antiretroviral treatment (ART) as a highly effective strategy to maintain an undetectable viral load to prevent the sexual transmission of HIV


  1. Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the use of antiretroviral agents in adults and adolescents with HIV. Washington (DC): Department of Health and Human Services; 2019. Available from:
  2. European AIDS Clinical Society. Guidelines: clinical management and treatment of HIV infected adults in Europe. Version 9.1. Brussels: European AIDS Clinical Society; 2018. Available from:
  3. Antiretroviral Drugs for Treatment and Prevention of HIV Infection in Adults 2018 Recommendations of the International Antiviral Society–USA Panel. Available from:
  4. Cohen MS, Chen YQ, McCauley M, et al. Antiretroviral therapy for the prevention of HIV-1 transmission. New England Journal of Medicine. 2016;375:830–839. Available from:
  5. Rodger AJ, Cambiano V, Bruun T, et al. Sexual activity without condoms and risk of HIV transmission in serodifferent couples when the HIV-positive partner is using suppressive antiretroviral therapy. Journal of the American Medical Association. 2016;316(2):171–181. Available from:
  6. The INSIGHT START Study Group. Initiation of Antiretroviral Therapy in Early Asymptomatic HIV Infection. New England Journal of Medicine. 2015;373:795–807. Available from: