Washington: If an HIV patient takes anti-retroviral drug therapy immediately, it vastly reduces the risk of transmitting the disease to an uninfected partner, a breakthrough global study released Thursday said.
By starting the drug regimen immediately rather than waiting for the illness to advance, the study showed a 96 percent fall in the transmission of HIV from the infected partner to the HIV negative one.
The randomized clinical trial began in 2005 and included 1,763 couples -- 97 percent of whom were heterosexual -- and was carried out at 13 sites across Africa, Asia and the Americas.
"This is excellent news," said Myron Cohen, lead investigator on the study and director of the Institute of Global Health and Infectious Diseases at the University of North Carolina at Chapel Hill.
"The study was designed to evaluate the benefit to the sexual partner as well as the benefit to the HIV-infected person," said Cohen.
"This is the first randomized clinical trial to definitively indicate that an HIV-infected individual can reduce sexual transmission of HIV to an uninfected partner by beginning anti-retroviral therapy sooner."
Under the randomized trial, some couples were placed into a delayed group in which the infected partner began taking antiretroviral therapy (ART) only when a type of T-cell known as CD4 dipped below 250 cells per millimeter cubed, or if he or she developed an AIDS related illness.
The other group began taking ART immediately. In that group, just one case of HIV transmission was observed.
There were 27 HIV transmissions in the delayed group, a difference the study described as "highly statistically significant."
National Institute of Allergy and Infectious Diseases chief Anthony Fauci hailed the findings.
"Previous data about the potential value of anti-retrovirals in making HIV-infected individuals less infectious to their sexual partners came largely from observational and epidemiological studies," said Fauci.
"This new finding convincingly demonstrates that treating the infected individual -- and doing so sooner rather than later -- can have a major impact on reducing HIV transmission."