Sub-Saharan Africa, the part of the world worst hit by Aids, is leading a fall in the number of new HIV infections, said the United Nations.
New infections in the area have dropped by more than a quarter in the last 10 years, show new figures.
"The data shows that countries with the largest epidemics in Africa - Ivory Coast, Ethiopia, Nigeria, South Africa, Zambia and Zimbabwe-are leading the drop in new HIV infections," the Joint UN Programme on HIV/Aids said in a statement.
"For the first time change is happening at the heart of the epidemic. In places where HIV was stealing away dreams, we now have hope," said Michel Sidibe from the United Nations Aids agency, UNAIDS. Better prevention methods and raising awareness are fuelling the decline, he said.
And young people have been key to the success, said UNAIDS. The agency said young people "are leading the prevention revolution by choosing to have sex later, having fewer multiple partners and using condoms, resulting in significantly fewer new HIV infections in many countries highly affected by Aids".
The use of condoms has also doubled in the past five years, while the report says that "tradition is giving space to pragmatism" in many communities.
Also the number of people getting HIV treatment in the region is 12 times what it was six years ago, bringing the total number of patients taking medication to 5.2 million.
In 2008, 67 per cent of global HIV infections came from sub-Saharan Africa. Sixty-eight per cent of new HIV infections there were among adults and 91per cent among children. The area also accounted for 72 per cent of the world’s Aids-related deaths in 2008.
But while progress is made in the worst-hit regions, other area such as eastern Europe and central Asia are reporting growing epidemics, said UNAIDS. There has also been resurgence of new infections among male homosexuals in developed nations, the agency noted.
"Challenges remain" in the global fight against HIV/Aids, the report, out on Friday said including expanding epidemics in Eastern Europe and Central Asia, and resurgence in new infections in wealthier nations among men who have sex with men.
The UN also asked for more money to be put into preventing HIV/Aids, warning that there is a $10bn (£6.4bn) shortfall in 2009. Countries most badly affected by HIV/Aids cannot handle the crisis on their own, it said.