July 20 (Bloomberg) -- HIV patients in developing nations should start treatment earlier than the World Health Organization recommends, a change that may save 76,000 lives in South Africa alone, a new study found.

Researchers from Harvard University used a mathematical model to predict that getting drugs sooner could also prevent about 66,000 cases of associated diseases such as tuberculosis in the next five years in South Africa, at an extra cost of about $1,200 for every year of life saved. The findings were published today in the journal Annals of Internal Medicine.

The projections should prompt health authorities to switch to earlier treatment now, rather than wait for the results of trials in South Africa in about five years, researchers led by Rochelle Walensky at Harvard’s medical school said in the study.

“Waiting five years for trial results could be costly in human terms,” Walensky and colleagues wrote. “Decisions must be made now.”

The WHO recommends starting HIV treatment when a patient’s CD4 cells -- the infection-fighting cells the virus attacks -- drop below 200 per cubic millimeter of blood, to delay the costs and side-effects associated with the drugs.

Developed nations such as the U.S. recommend starting treatment when CD4 cells drop below 350, and two studies published this year have shown patients who get drugs when those cells fall under 500 have higher survival rates. Healthy people have between 800 and 1,200 CD4s per cubic millimeter of blood.

Limit Spread

Raising the threshold to 350 for patients in developing nations would be “more appropriate and clinically sound,” said Julio Montaner, the president of the International AIDS Society, in a speech at the group’s conference in Cape Town yesterday.

Starting treatment earlier would also prevent people with HIV from spreading it because the drugs reduce the virus to such low levels it’s harder to pass on, Walensky said.

After the failure of Merck & Co.’s experimental vaccine in 2007, the use of approved drugs to both treat and prevent HIV “is perhaps the most pressing question in HIV research,” Kevin De Cock, the WHO’s outgoing director of HIV/AIDS, said in the agency’s bulletin earlier this month.

The agency is organizing a meeting of researchers later this year to consider the matter, De Cock wrote.

Walensky and colleagues compared the likely effect of three scenarios: starting treatment when CD4s fall below 250, when they drop below 350, or when no treatment is given. Assuming that current infection rates in South Africa continue and 30 percent of those infected are diagnosed, 76,000 lives would be saved over the next five years if treatment was started at the higher level, the researchers said.

About 5.7 million people have HIV in South Africa, more cases than in any other nation, according to UNAIDS, the United Nations’ AIDS agency.

The extra costs are reasonable relative to South Africa’s gross domestic product per capita, the researchers said.

The study was funded by the National Institute of Allergy and Infectious Diseases and the Doris Duke Charitable Foundation.

To contact the reporter on this story: Simeon Bennett in Singapore at sbennett9@bloomberg.net

Last Updated: July 20, 2009 12:00 EDT