Lessons from the history of the human immunodeficiency virus/acquired immunodeficiency syndrome epidemic among Spanish drug injectors.

In Spain, approximately 10 years passed between the time when human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) harm-reduction programs should have been developed with sufficient coverage to have an optimum impact on public health (before the HIV/AIDS epidemic's explosion in 1984) and the date of their actual implementation. This delay yielded an enormous cost for the country. The introduction of the virus in drug injector networks during a period of widespread diffusion of heroin injection and the lack of political awareness of the growing problem were 2 important factors that contributed to the important diffusion of the HIV infection among Spanish injection drug users. Lessons can be learned that may be of great interest in countries or territories facing similar challenges now and in the future.