This is the VOA Special English Health Report.

For people infected with HIV, the earlier they start treatment, the better -- and better not just for them. A new study shows that early treatment greatly reduces the risk that the partner of an infected person will also get infected. HIV is the virus that causes AIDS.

Dr. Anthony Fauci is with the United States National Institutes of Health which paid for the study.

ANTHONY FAUCI: "Many studies have been showing that the earlier you start, the better it is for the person who is infected. This study shows that not only is it better for the person who is infected, but it helps that person from transmitting to the person that's their sexual partner, heterosexual partner."

Researchers cannot say if the results would be the same in men who have sex with men. Most of the couples in the study were heterosexual.

The study took place in Botswana, Brazil, India, Kenya, Malawi, South Africa, Thailand, the United States and Zimbabwe. It involved almost 2,000 couples divided into two groups.

In one group, the infected man or woman began to take a combination of three antiretroviral drugs immediately after being found to have HIV. In the other group, the infected partners began drug treatment only when they started to show signs of getting AIDS.

The researchers say both groups received equal amounts of HIV-related care and counseling. That included information about safe sex practices, free condoms and regular HIV testing.

The study began in 2005. It was supposed to last until 2015. But researchers stopped it early because the results were so clear. Only one case of infection was reported in couples where the infected partner began immediate treatment.

Dr. Fauci says earlier treatment led to a 96 percent reduction in the spread of HIV to uninfected partners.

ANTHONY FAUCI: "This is a powerful bit of evidence that will go into the thinking and formulation of guidelines and of global policy, policy by WHO, by UNAIDS, by the international organizations that help to provide drugs in the developing world."

The study shows the value in testing and treating HIV before a person even feels sick enough to see a doctor. But in many countries, public health budgets are already stretched thin. In sub-Saharan Africa, the area hardest hit by AIDS, for every person who gets treated, two others go untreated.

Antiretroviral drugs suppress the virus. Once people start treatment, they have to continue it daily for the rest of their life.

And that's the VOA Special English Health Report. To read and listen to our reports, go to voaspecialenglish.com. I'm Jim Tedder.

heterosexual: a person who is sexually attracted to people of the opposite sex 异性恋者

antiretroviral: 抗逆转录病毒

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（来源：VOA 编辑：崔旭燕）