Over the past 5 years --for the first time in the history of the acquired immunodeficiency syndrome (AIDS)epidemic --the number of new AIDS cases and deaths fell,and in 1998,the number of AIDS deaths declined by almost two-thirds from the all- time high that was recorded in 1995.These declines can be attributed to advances in antiretroviral therapies and to a number of HIV prevention efforts carried out by government agencies,nonprofit organizations,and the private sector.