lobally, the number of new HIV infections in 2010 was 21% down on that peak, seen in 1997, according to UNAids 2011 report.
The organisation says both falls have been fuelled by a major expansion in access to treatment.
Its executive director, Michel Sidibe, said: "We are on the verge of a significant breakthrough."
He added: "Even in a very difficult financial crisis, countries are delivering results in the Aids response.
"We have seen a massive scale up in access to HIV treatment which has had a dramatic effect on the lives of people everywhere."