Using HIV treatment as prevention should be an urgent priority, says Dr. Julio Montaner. ((STR/AFP/Getty))

The strategy of giving a cocktail of anti-HIV drugs to prevent the spread of the infection should be expanded immediately worldwide, a Canadian HIV researcher says in a medical journal commentary.

Studies suggest that a combination of antiviral drugs known as highly active anti-retroviral therapy (HAART) helps treat HIV and also prevents its transmission, by reducing how infectious someone is.

In Taiwan, British Columbia and San Francisco, the treatment as prevention approach has been associated with declining numbers of new HIV diagnoses.

Dr. Julio Montaner of the B.C. Centre for Excellence in HIV/AIDS in Vancouver calls treatment as prevention "a double hat-trick" in Thursday's online issue of The Lancet.

The first hat-trick is preventing death, illness and transmission. The second is how it works to prevent transmission between mother and child, sexual partners and injection drug users, he said in an interview.

"The evidence is in: treatment is prevention," Montaner wrote.

"Treatment dramatically prevents morbidity and mortality, HIV transmission, and tuberculosis. Furthermore, treatment prevents HIV transmission in [mother-to-child], sexual, and injection drug use settings; indeed, a very welcome double hat-trick. The challenge remains to optimize the impact of this valuable intervention. Failure to do so is not an option."

Treatment reduces new infections

Current HIV treatment reduces the level of HIV in the blood to undetectable levels, thus improving  the health of HIV-positive individuals. At the same time, the treatment decreases the level of HIV in sexual fluids to undetectable levels, thereby reducing the likelihood of  HIV transmission by over 90 per cent.

In May, an International AIDS Society workshop in Vancouver concluded that treatment as prevention has progressed from "a testable hypothesis to an urgent implementation priority."

But for 10 years, there has been a tension between those advocating to pursue every question before implementing treatment as prevention and those advocating for research to done as part of implementation, the editorial said.

Meanwhile in June, UNAIDS pushed world leaders to commit to a target of treating 15 million people by 2015.

"We need political leadership to assure that 15 million by 2015 is actually delivered," Montaner said.

He will be attending next week's International AIDS Society conference in Rome, where more findings on the treatment as prevention approach will be presented.