About four million people are now getting AIDS drugs worldwide — a 10-fold increase in five years — but five million others are still in dire need of the medicine, UN health officials estimated in a report issued Wednesday.

The figures represent a major increase in rolling out drugs to patients across Africa, where the AIDS epidemic is focused, even though they were based on incomplete data and modelling.

'We really need to do something about preventing HIV because there are more people getting infected every year than there are being put on treatment.'— David Ross

They were released in an annual AIDS report jointly published by the World Health Organization, UNICEF and the UN AIDS program.

"Even though some of the data are not fully clear and there are some unanswered questions, this is a dramatic improvement," said Daniel Halperin, an AIDS expert at Harvard University. "It shows that all this money that has gone to treatment has made some difference."

Need for AIDS drugs in sub-Saharan Africa

In 2008, officials estimated more than four million people were on AIDS drugs in low- and middle-income countries. The biggest increase was in sub-Saharan Africa, where nearly three million people are now on the drugs.

Overall, about 44 per cent of people with HIV in sub-Saharan Africa who need AIDS drugs are now taking them. In the U.S., about 71 per cent of patients in need got AIDS drugs, according to 2003 data from the Centers for Disease Control and Prevention.

"We have invested a lot of funds into HIV/AIDS, but it has been a worthwhile investment because we have saved lives," said Dr. Teguest Guerma, WHO's acting AIDS director.

The authors admitted "there remain uncertainties related to the quality of data reported."

Of the UN's 192 member countries, 158 provided government-approved data, most of which was not independently verified.

Last year, the world spent nearly $9 billion US on AIDS. For every dollar spent on public health, AIDS gets about 23 cents. It causes about four per cent of deaths globally.

Guerma said the number of people who need AIDS drugs might double by the end of the year because WHO is considering revising its treatment guidelines. Several studies have suggested AIDS patients could live longer if they started taking drugs sooner.

Now that millions of AIDS patients are on treatment, some experts says it's time for the UN to focus on other strategies for stopping the outbreak.

"We really need to do something about preventing HIV because there are more people getting infected every year than there are being put on treatment," said David Ross, an AIDS expert at the London School of Hygiene and Tropical Medicine.

At a news conference in Johannesburg, Dr. Nono Simelela, head of South Africa's National AIDS Council, said it had asked the country's Health Department to draw up policies on circumcision.

Studies have shown that circumcision can reduce a man's chances of catching HIV by up to 60 per cent.

Prevention strategies

South Africa has the world's largest number of HIV cases, about 5.5 million people. About 700,000 South Africans are on AIDS drugs, Simelela said.

She also called for other prevention strategies, including addressing the stigma around AIDS and encouraging an open, fact-based discussion of sex.

"That's where we are missing the mark," Simelela said. "The social, moral regeneration must come to the fore."

Experts warned it would be challenging to continue financing AIDS programs, given the global financial crisis. And since patients must take AIDS drugs for the rest of their lives, the cost of treatment programs will continue to increase, particularly when drug resistance develops and more expensive drugs are needed.

"The fact that WHO has come closer to meeting its target of universal AIDS treatment is certainly a good public relations coup," said Philip Stevens, a director at International Policy Network, a London-based think-tank . "Whether or not this is sustainable as billions more dollars are needed in the future is an entirely different question."