健康英语新闻:Study shows early treatment with antiretroviral therapy prevents HIV transmission

WASHINGTON, May 12 (Xinhua) -- Early initiation of antiretroviral treatment in people infected with HIV prevents them from transmitting the virus to their partners, according to findings released Thursday from a large-scale international clinical study.

The study, known as HPTN 052, was designed to evaluate whether antiretroviral drugs can prevent sexual transmission of HIV infection among couples in which one partner is HIV-infected and the other is not. The results are the first of their kind from a major randomized clinical trial.

Led by Myron Cohen, of the University of North Carolina, the research found that treating HIV-infected individuals with antiretroviral therapy (ART) when their immune systems are still relatively healthy led to a 96 percent reduction in HIV transmission to their partners.

This critical new finding convincingly demonstrates that early treatment of infected individuals can have a major impact on the spread of the epidemic.

study investigators enrolled 1,763 couples who were not eligible for ART by WHO standards in nine countries around the world. All couples were at least 18 years of age. The vast majority of the couples (97 percent) were heterosexual, which precludes any definitive conclusions about effectiveness in men who have sex with men.

Couples were randomly assigned to one of two study groups. In the first group, the HIV-infected partner initiated antiretroviral therapy (ART) as soon as the couple enrolled in the study (the immediate treatment group); in the second group, infected partners did not begin ART until their CD4+ counts fell to between 200 and 250 cells/mm3 or they developed an AIDS-related illness (the delayed treatment group). Couples in both groups received HIV primary care, counseling and condoms.

Results of this research study, which was scheduled to conclude in 2015, are being released early, after the independent data and safety monitoring board (DSMB) determined that the benefits of early treatment were clear.