HIV patients reduced the risk of transmitting the virus to their sexual partners by 96 percent if they took took oral antiretroviral meds when their immune systems were relatively healthy, according to results of a study sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.

The trial, which involved 1,763 mostly heterosexual couples where only one partner had HIV, may have the potential for changing care for HIV patients. Right now, the World Health Organization recommends HIV meds are not given patients until the virus reaches a certain threshold. In half of the couples, the infected partner was put on HIV meds as soon as the person tested positive for the virus. In the other half, the infected person started treatment only when the immune systems weakened, based on cell counts.

The study found 28 HIV cases linked to the infected partner. Among infected partners who were immediately given meds, one person developed the virus. The 27 other infections were among the 877 couples with infected partners who were given delayed treatment.

“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,” Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, says a statement in which he notes the study was halted early to ensure HIV patients received meds in order to protect their partners.

UPDATE: We received a statement from Doctors Without Borders: “This study confirms that getting people on treatment sooner rather than later, could break the back of the epidemic. Here in Khayelitsha, South Africa, we are seeing early signs that HIV infections have been on the decline since the introduction of large-scale HIV/AIDS programs that have put many people on treatment. This means that treatment is a form of prevention,” says Gilles van Cutsem, DWB’s medical coordinator in South Africa. “The bottom line is that this new research shows that there is light at the end of the tunnel.”

These 11 HIV drugs were used in various combinations:

•atazanavir (300 mg once daily)
•didanosine (400 mg once daily)
•efavirenz (600 mg once daily)
•emtricitabine/tenofovir disoproxil fumarate (200 mg emtricitabine/300 mg tenofovir disoproxil fumarate once daily)
•lamivudine (300 mg once daily)
•lopinavir/ritonavir 800/200 mg once daily (QD) or lopinavir/ritonavir 400/100 mg twice daily (BID)
•nevirapine (200 mg taken once daily for 14 days followed by 200 mg taken twice daily)
•ritonavir (100 mg once daily, used only to boost atazanavir)
•stavudine (weight-dependent dosage)
•tenofovir disoproxil fumarate (300 mg once daily)
•zidovudine/lamivudine (150 mg lamivudine/300 mg zidovudine taken orally twice daily)