TORONTO, Aug. 16 (Xinhua) -- Canada's Vancouver will launch a pilot study to test the theory that expanding antiretroviral drug treatments will dramatically reduce HIV transmissions, officials announced Wednesday.

    When taken correctly, antiretroviral drugs suppress to undetectable levels the amount of HIV virus in the bloodstream, said Dr. Julio Montaner, head of the British Columbia Centre for Excellence in HIV-AIDS.

    "The number of new cases that could be averted is astronomical," Montaner said at the International AIDS Conference in Toronto.

    Montaner's theory, outlined earlier this month in a review published by the journal "Lancet", is that by putting as many HIV positive people as possible on the drugs, new infections would plummet dramatically.

    Such a plan would require substantial upfront spending to avert the huge down-the-road costs associated with new infections, Montaner said estimating that for every Canadian dollar (0.89 US dollar) spent on treatment, 2 Canadian dollars (1.8 dollars) in health-care costs could be avoided.

    However, there are substantial challenges to this theory. It is estimated that 90 percent of people worldwide who are HIV positive are unaware they carry the virus.

    Therefore, unless more people agree to be tested and begin the antiretroviral drug therapy, Montaner's plan could not work.

    Another issue is getting drugs to the people who need them. Dr. Kevin de Cock, HIV director for the World Health Organization, said the Geneva-based agency estimates some 6.8 million people with HIV need antiretroviral treatment now, but only 1.65 million are actually getting access to the lifesaving drugs. Enditem