Ending AIDS Epidemic Seen as Multi-Front War

TORONTO, Aug. 18 -- The scientists, health workers and activists fighting AIDS long ago gave up the idea they could kill the global epidemic with a single blow. But they are beginning to think it might be possible to bleed it to death with a thousand cuts.

That was among the things on the minds of 26,000 delegates to the 16th International AIDS Conference as they headed home and the huge, biennial, multi-ring circus struck its tent yesterday.

There are two large studies underway testing whether -- and by how much -- circumcision reduces a man's chance of becoming infected with the AIDS virus. Five different "microbicides" -- gels that block or kill the virus during intercourse -- are being tested on thousands of women in Africa. Five thousand are trying out an anti-HIV diaphragm.

Scientists are a year or two from learning how much they can cut the risk of HIV infection by treating people for herpes. Men and women on three continents are in experiments to see whether taking a single dose of an antiretroviral drug before sex can block infection.

And then there is the idea of just doing more of what the world has been doing furiously for the past two years -- putting more infected people on life-saving AIDS drugs. Studies presented this week provided yet more evidence that treatment may itself be a great strategy for prevention.

If even some of these approaches turn out to be successful -- and there is good evidence for all of them -- the cumulative effect could profoundly change the trajectory of the 25-year-old AIDS epidemic.

"Taken together, it feels as though we may have found a potential turning point. We may look back on this as an important moment," said Stephen Lewis, the U.N. special envoy for AIDS in Africa, as the conference closed.

The 25-year journey from AIDS's discovery in Los Angeles in 1981 to this conference is littered with the bones of bright ideas and great hopes -- and the bodies of 25 million who have died from the disease. Participants are hesitant to announce the dawning of an era of prevention that could eventually lead to the epidemic's end. That said, there was little doubt the meeting ended on a note of optimism and anticipation.

AIDS has been so disastrous in part because infected people survive a long time, are often unaware of their infection for years and are capable of transmitting the virus the whole time.

The strategy of getting everyone tested for HIV -- which is being pushed in U.S. cities as well as in African villages -- permits infected people to be identified early and to take steps -- both behavioral and pharmaceutical -- to make them less infectious.

If uninfected people can also use new protective strategies, the combined effect will be that each round of HIV infection will be smaller than the one before. The epidemic will contract. Eventually, it will crash.

The potency of AIDS treatment as a prevention tool is evident from studies of couples in which one person has HIV and the other does not. If the infected person has very little HIV in the bloodstream (a low "viral load" in medical parlance), the chance of the partner becoming infected is close to nil. The way to lower viral load is to take three-drug combinations of antiretroviral drugs -- "triple therapy."