Research Profile – Going Non-Viral: Achieving HIV Suppression

A collaboration of researchers is studying a comprehensive dataset of over 8,000 people on antiretroviral HIV therapies to assess how Canada is dealing with the HIV/AIDS epidemic.

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Dr. Curtis Cooper

Angela Cescon

A Canadian living with the human immunodeficiency virus (HIV) is most likely to achieve "viral suppression" if they are male, reside in Ontario and have no history of injecting drugs, according to findings drawn from the largest databank of national HIV patient information ever collected.

Achieving viral suppression – reaching and maintaining the point at which the virus is under control – is crucial for two reasons: it prevents an HIV-positive person from progressing to AIDS, and it helps stop the spread of HIV.

"By suppressing someone's viral load, they are much less likely to become ill with HIV," says Dr. Curtis Cooper, a University of Ottawa researcher and a regional director of the Canadian Observational Cohort (CANOC). "On a public health basis, it protects the population because the risk of transmitting HIV with a fully suppressed viral load is minuscule. I would not say you cannot transmit it, but it reduces the risk of transmission multifold."

CANOC has collected data from over 8,000 patients in British Columbia, Ontario and Quebec who are receiving highly active antiretroviral therapy (HAART), the standard of care for HIV infection. In a study published last year in the British journal HIV Medicine, CANOC's researchers reported that the median time for a Canadian HIV patient to reach viral suppression is 4.5 months.

"If you look at the clinical trials, it usually takes between two and four months to fully suppress people on therapy," says Dr. Cooper, "so that would suggest we – patients and health care providers – are doing a pretty good job."

But there is absolutely no cause for complacency, he points out. Women in Canada tend to do less well on the therapies than men, as do those facing additional difficulties.

"The challenging part is for patients who have mental health issues, substance abuse issues or housing issues," says Dr. Cooper. "Those are the big barriers to getting people to successfully launch therapy and achieve optimal results."

Knocking down barriers and implementing programs to increase access to treatment and services means understanding the issues that patients face and making researchers, health providers and policy makers aware of them.

"The socio-demographic factors are important, in terms of having access to treatments and being able to adhere to treatments," says Angela Cescon, lead author of the 2011 study. "Our analysis is the first step in identifying those individuals who aren't experiencing [viral] suppression."

With the help of funding from the Canadian Institutes of Health Research, CANOC researchers have been analyzing data collected from nine cohorts of HIV-positive individuals who began their HAART therapies in 2000 or later. The plan is to expand the collaboration into other provinces – Saskatchewan is next – and to begin examining issues such as aging and HIV.

"Now we want to look at the development of co-morbidities as people age and are on HIV treatment for longer periods of time," says Ms. Cescon. "We hope to be able to collect more detailed information about cancer and liver and renal diseases and cardiovascular disease, with the ultimate aim being to improve the health and well-being of persons living with HIV across Canada."

"The important thing is that we have a good understanding of what's going on in the major three provinces where HIV infection has had an impact. We hope to expand beyond the borders of those three provinces and move into other regions where the epidemic is now increasing."
– Dr. Robert Hogg, CANOC Principal Investigator and Director of the Drug Treatment Program at the British Columbia Centre for Excellence in HIV/AIDS
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