Starting treatment for HIV immediately after diagnosis is the most effective method yet discovered for preventing an infected partner from passing the virus that causes AIDS to a healthy partner, according to many experts.
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A U.S. National Institutes of Health sponsored international study of 1,763 mostly heterosexual couples released Thursday finds that the drugs used to treat AIDS can almost totally eliminate the transmission of the virus.
The study began in 2005 and was supposed to last 10 years. But the results were so dramatically positive that a committee that monitors the results halted the study five years early.
In all the couples, one partner was infected and the other was not. In half of the couples in the study, the infected partner got the drugs used to treat HIV infection immediately at the start of the study. In the other half, the infected partner got the drug at the normal medically indicated time — when his or her immune system began to deteriorate. At the time the study began, the HIV-infected partners had CD4 T-cell levels — a key measure of the immune system — of between 350 and 550 cells per cubic millimeter. A normal count is between 500 and 1,500.
In the 882 couples where the drugs were used in the normal way, 27 partners became infected with HIV. But in the 881 couples where treatment began early, only one was infected.
Previously, anecdotal reports have indicated that people who are being treated with the drugs are less likely to infect others. Scientists say it makes sense because the drugs reduce the amounts of virus in the body. But this is the first study to rigorously prove the concept.
During the study, both group were counseled on safe sex and given free condoms.
The study was carried out a several sites, mostly in African and Asian countries.
There were very few couples in the United States. Only a few gay male couples were in the study so officials say they can not draw any rigorous conclusions for that population. But many infected gay men in the U.S. and other countries, according to doctors, already, take the drugs to reduce the risk of infection. However, officials emphasize that this medical approach should never be used as an approach for safe sex practices.
The study also raises the issue of access to the drugs in poor countries. Already — for financial reasons — only a small percentage of people who need the drugs to save their lives get them. Expanding the use for the prevention of transmission raises the same issues of access to the drugs.
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