摘要
BACKGROUND Liangshan,officially the Liangshan Yi Autonomous Prefecture,is an autonomous prefecture occupying much of the southern portion of Sichuan Province.It has been a remote and deeply impoverished area and also has the largest population of ethnic Yi people in China(1).For many years,due to geographical environment conditions,traffic conditions,and other historic restrictions,the human immunodeficiency virus(HIV)epidemic in Liangshan Prefecture has become the focus of HIV prevention and control in China since the first acquired immunodeficiency syndrome(AIDS)case was reported in this area in 1995(2-3).
