Thousands of government officials and health care workers from across Asia gathered in Sri Lanka on Sunday for an international conference aimed at ensuring the AIDS epidemic does not worsen in the region. «The Asia and Pacific region has a low prevalence of HIV/AIDS, but the challenge across the countries is to keep the prevalence low,» Deborah Landey, deputy director of UNAIDS, told a news conference ahead of the start of the 8th International Congress on AIDS in Asia and the Pacific. An estimated 8.6 million people in the region are infected with HIV, the virus that causes AIDS. That number, though considerable, remains far below the rate in sub-Saharan Africa, where 25.8 million people are infected, the Associated Press reported. The conference, whose theme is «Waves of Change, Waves of Hope,» begins Sunday evening and runs until Thursday. It aims to bring together 2,500 policy makers and health professionals from around the region to share their experiences in fighting the spread of the disease and in treating and supporting those already infected, Sri Lankan Health Secretary Athula Kahandaliyanage said.