Nearly three million people with HIV/AIDS in developing countries had received anti-retroviral drugs by the end of 2007, said the World Health Organisation Monday: seven times more than four years ago.
"This is a remarkable achievement for public health," WHO Director General Margaret Chan told journalists.
"This proves that, with commitment and determination, major obstacles can be overcome," she added. Around three quarters of new treatment cases were in Africa.
But a WHO co-authored report found that much more needed to be done: despite the increase, an estimated 6.7 million people in need of anti-retrovirals were still unable to access medicines, out of a total of 9.7 million.
The report, produced in conjunction with UNAIDS and UNICEF, said that the rise was due to the increased availability of drugs, in part due to price cuts, but also to delivery systems better adapted to specific country needs.
But there was also increased demand for the treatment, as the number of people tested and diagnosed with HIV climbed, the WHO noted.
The report took heart from the rising number of women able to access retrovirals and prevent transmission of HIV to their unborn children -- up to nearly 500,000 from 350,000 in 2006.
"The prevention of mother-to-child transmission has improved, but far too many women learn of their infection status only when pregnant or during delivery," Chan said.
But UNICEF vice-chairman Pascal Villeneuve pointed out that 2.1 million children below the age of 15 were living with HIV/AIDS in 2007, and that 90 percent of them had become infected via their mothers.