The number of people living with HIV has passed 40 million for the first time.
Almost five million people were infected by HIV globally in 2005, the highest jump since the first reported case in 1981, taking the number living with the virus to a record 40.3 million, according to a United Nations report.
UN report
UNAids says new infections have been fuelled by the epidemic's continuing spread in sub-Saharan Africa and a rise in the former Soviet Union and Eastern Europe.
"Despite progress made in a small but growing number of countries, the Aids epidemic continues to outstrip global efforts to contain it," the report said.
More than 3.1 million people have died this year from Aids including 570,000 children - far more than the toll from all natural disasters since last December's tsunami.
Southern Africa, including South Africa - which has the highest number of cases at more than five million - continues to be worst-hit.
Focusing on the upward spiral in South Africa where the infection rate among pregnant women touched 29.5 percent in 2005, the report said deaths of people in aged between 25 and 44 had more than doubled.
Other southern Africa countries such as Botswana, Lesotho, Namibia and Swaziland had high rates of HIV among pregnant women - more than 30 per cent - and sign of growth rates stabilising.
Sub-Saharan Africa is home to 25.8 million HIV-positive people, or 64 per cent of the world's total.
Two decades into the HIV/Aids epidemic, the report said that in many parts of the world, including southern Africa, knowledge about HIV transmission was alarmingly low.