Three periods can be distinguished in the brief history of global AIDS: silence, discovery and mobilization. The first period, starting in the mid-l970s, was the time of the “silent pandemic,” during which HIV spread — unnoticed—to at least five continents. During this period, when the virus was unrecognized, HIV could have — but did not — spread even more widely.

The description of AIDS in 1981 ended the silence and initiated the second period in the history of global AIDS — a period of discovery which culminated symbolically at the first International Conference on AIDS in June 1985 (Atlanta, USA). During this period, the modes of transmission were defined, the virus was discovered, and the capacity to detect anti-viral antibodies led to the discovery of large numbers of infected persons and to awareness of the long latency between infection and manifest disease.