An international AIDS meeting in Rome has wrapped with a dose of optimism on preventing the spread of HIV.

Scientists attending the four-day meeting of the International AIDS Society presented the results of trials on how to essentially stop the spread of AIDS.

Delegates celebrated the results of a trial of 1,763 heterosexual couples where one partner was infected with HIV while the other was HIV-free. Investigators showed that giving antiretroviral drugs to an infected person not only helps them to live longer but also dramatically reduces the chance of spreading the virus to others.

"By treating people infected with HIV, we decreased the likelihood of transmission of the virus by 96.3 per cent," said Julio Montaner of the BC Centre for Excellence for HIV and AIDS, who is involved in the research. "This is dramatic. Nothing works as well when it comes to decreasing HIV transmission as treatment does."

The treatment as prevention approach works by forcing the virus to retreat instead of circulating in the blood or other body fluids where it can be transmitted.International political commitment is needed to expand HIV treatment, scientists and activists say.International political commitment is needed to expand HIV treatment, scientists and activists say. Shannon Stapleton/Reuters

Montaner wants efforts stepped up to expand treatment, especially to vulnerable women and children, and those at high risk, including sex workers and intravenous drug users.

Michel Sidibe, the executive director of UNAIDS, said about 9 million people who could benefit from the therapy are not getting it.

Political commitment

Now, political commitment is needed to make sure drugs, health services and educational programs are available to those in need.

Montaner is frustrated with the progress on that front.

Seeking a cure

The Rome Statement for an HIV Cure calls for a move towards a "functional cure" — permanently suppressing the virus in the body to such a low level that it can do no harm and cause no further infections.

"Today, there is a reemergence of hope that the long-term remission of an infected individual is a realistic objective," IAS 2011 International chair and president Elly Katabira said in a statement.

"Within my lifetime, I have seen a raging epidemic now coming under control therapeutically and again now a unique opportunity to stop it altogether. And yet the political leadership is looking the other way. They are not interested," Montaner said.

Expanding treatment is within reach if the international community responds, said Richard Elliott, head of the Canadian HIV/AIDS Legal Network in Toronto.

"We've shown that you can put millions of people successfully on treatment in the course of a few years," said Elliott. "There's no reason why we can't keep building on that success if there's a willingness to do it."

The International AIDS Society stages a scientific conference every two years, with the next scheduled for Kuala Lumpur, Malaysia in 2013. The forum alternates with the wider International AIDS Conference, which next year takes place in Washington.

With files from CBC's Kelly Crowe and Maureen Brosnahan