HEALTH -- May 16, 2011 at 5:26 PM EDT
Early HIV Treatment an Effective -- But Costly -- Prevention Method
HIV medication. Photo by AFP/Getty
Get HIV-positive patients on antiretroviral treatment. Now.
That's the message from the landmark new study from the National Institute of Allergy and Infectious Diseases showing that early treatment of HIV can help stop spread of the disease to sexual partners at an astonishingly high rate.
In the study, patients put on immediate HIV treatment were 96 percent less likely to pass the disease on to their partners, compared to patients who only received treatment later in the progression of the disease.
The study involved 1,763 couples in nine countries, all with one partner who was HIV positive and one who was not. Half of the HIV positive participants were put on HIV medication immediately, half only began treatment if their CD4 counts, a measure of immune health, fell below 250. Of the 28 new HIV infections that arose during the study linked back to the participants partner, only 1 was from a patient put on immediate antiretroviral therapy.
It was a concept health workers were already on board with: that HIV medication lowers the viral load of the patient, reducing the chance of transmission, but the study was the first to give hard evidence of the effect in a large-scale trial.
"The effect in this trial was very big, even for believers it was very surprising that is was so effective at preventing transmission," said Kevin Robert Frost, CEO of amfAR, the foundation for AIDS Research. But, he warned, "it's going to present enormous challenges."
While the premise may be simple -- get people tested, diagnosed and on antiretrovirals quickly -- putting it into practice will be difficult. Antiretrovirals have to be taken daily, for life, and access to treatment is already a big problem in many countries.
"[In developing countries] about 30 to 40 percent of people who would benefit are receiving therapy. Sixty percent-plus are not," said Anthony Fauci, the director of NIAID, which conducted the study.
He urged a recalculation in the cost-benefit analysis now that the study provides evidence treatment could be one of the most effective prevention methods available for HIV.
"I would say that the WHO, UNAIDS and the U.S. government should realize from this study that an investment like this in treatment is also an investment in prevention," Fauci said.
There are 10 million people around the globe already in need of HIV drugs and not receiving them, according to UNAIDS, a pool that grew larger in 2009 when the World Health Organization changed its recommendations to advocate treatment for patients at a 350 CD4 count, which is a healthier immune level than previously recommended.
The new study implies this pool would grow even larger if treatment is to be used as a prevention method.
Rifat Atun, director of strategy for the Global Fund to fight AIDS, Malaria and Tuberculosis, one of the largest providers of funding for HIV/AIDS, said the study ought to encourage funders and donors to allocate more funds to antiretroviral treatment because of the very strong result of the study.
"It has major implications for provision of antiretroviral treatment," he said. "We now have very good evidence that antiretroviral treatment has a very important preventive effect and that could really transform the approach to the HIV/AIDS epidemic going forward."
About 3.5 million people around the globe are currently on the drugs through Global Fund supported groups, out of more than 5 million receiving the drugs worldwide. On average it cost $380 to keep a patient on the medication for a year in Global Fund countries.
Atun said the next step is to wait for any new guidance from the World Health Organization on the point of drug initiation. It will also be vital to demonstrate the effectiveness of the intervention in different settings and build country capacity to handle increased scale up of the medication.
Some countries will be able to increase their provision of antiretrovirals quickly, he said, while others may need time to put the right resources in place to handle a new policy.
"We need to have a long-term view," Atun said, "Ensuring that the benefits are maintained because this requires people take treatment over a long period of time."
Frost, Fauci and Atun all agreed that antiretrovirals will never be able to stop HIV alone, but need to be used as part of a comprehensive strategy involving other forms of prevention, including condoms, male circumcision, microbicides and development of a vaccine.
Proving that using antiretrovirals as prevention works on a community scale will also be a vital next step said Frost. Two studies going on now in Washington, D.C. and the Bronx look at just issue -- whether starting people on treatment right after diagnosis will actually lower transmission on a population level.
"There are problems with adherence in certain places because the drugs are toxic so getting people onto treatment and keeping them on treatment is a challenge," Frost said. These studies will help determine how challenging it will be to draw people into the testing system and, if they test positive, convincing them to begin lifelong treatment immediately and stay on it.
Fauci said he hopes the study results will encourage people to find out their status, as a first step.
"If you look at the U.S., you have 1.1 million people infected with HIV and 21 percent who still do not know they are infected," he said. "So this should create a big push to get people to seek out voluntary testing and linking to care and treatment."