Expert Commentary

Prevention of HIV infection with early antiretroviral therapy

2011 study sponsored by the National Institute of Allergy and Infectious Diseases on the potential of early antiretroviral treatment to reduce HIV transmission.

Couple embracing (iStock)

According to a study by the Centers for Disease Control and Prevention, in 2009 there were approximately 48,100 new HIV infections in the U.S. among persons 13 and older. While this represented a slight increase over the 2008 total of 47,800, the researchers characterized the overall rates as “stable” — a serious concern after years of HIV education and prevention efforts. As of 2010, more than 1.2 million people in the United States and over 34 million in the world were living with the AIDS virus.

Because the majority of new infections are through sexual contact — in 2009, the rate in the United States was 88% — finding new ways to reduce transmission between partners has become increasingly important. A clinical trial sponsored by the U.S. National Institute of Allergy and Infectious Diseases and published in the New England Journal of Medicine in 2011, “Prevention of HIV-1 Infection with Early Antiretroviral Therapy,” looked at the effects of early treatment of healthy HIV-positive individuals on them and their partners.

The study involved 1,763 couples age 18 years or older in nine nations around the world. The HIV-positive partners all had CD4 T-cell counts between 350 and 550 cells per cubic millimeter within 60 days of entering the study. HIV-negative partners had all been tested for the virus within 14 days. Couples were divided into two groups: In the first, HIV-positive participants immediately began taking antiretroviral drugs; in the second, they did so only when their CD4 counts fell below 250 or they experienced AIDS-related symptoms. All couples received safe-sex counseling, condoms and medical treatment for sexually transmitted infections.

The findings include:

  • During the trial, 39 previously uninfected partners became HIV-positive. In 28 of these, genetic analysis matched the virus to that of their HIV-infected partner. Seven cases were not linked to the partner, and four were inconclusive.
  • Of the 28 infections between partners, 27 occurred in the group in which the HIV-infected partner did not begin antiretroviral therapy immediately. “This finding was statistically significant and means that earlier initiation of antiretrovirals led to a 96% reduction in HIV transmission to the HIV-uninfected partner,” the researchers stated.
  • In all, 20 cases of extrapulmonary tuberculosis occurred. Of these, 17 were among HIV-positive participants who did not immediately begin antiretroviral therapy and the remaining three among those who did have such therapy. These results were considered “statistically significant.”
  • Twenty-three deaths occurred during the study: 13 in the group that did not immediately begin antiretroviral therapy and 10 among those who received immediate treatment. This difference “did not reach statistical significance.”

The trial had been anticipated to continue until 2015, but the findings were released after an interim review by an independent data and safety monitoring board. “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,” the study states.

One limitation of the study is that because nearly all participants were heterosexual (97%), no definitive conclusions could be made about the effectiveness of the treatment for gay and bisexual men.

Keywords: HIV/AIDS, HIV, AIDS, gay issues

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