ABSTRACT
The author presents a global overview of the AIDS pandemic from its appearance in 1981 to the present; including the discovery of the HIV virus in 1983. 851;628 cases have been notified to the World Health Organization. Reference is made to the groups initially affected and at high risk-male homosexuals and drug users-and their sexual partners. Attention is drawn to the three modes of transmission known today-sexual; parenteral; and vertical- and to their contribution to the dynamic nature of the epidemic. The increase in heterosexual transmission in industrialized countries; the rapid spread of the virus through heterosexual intercourse and the safety of blood transfusion in underdeveloped countries; and mother-child transmission are discussed. Reference is also made to the impact on health; social life; the economy; politics and religion; with emphasis on underdeveloped countries; namely in Africa. The regions in Africa with the highest prevalences of HIV-2 infection are discussed. finally; the author analyses in detail the spread of HIV-2 in Western Africa; including the higher prevalence of HIV-2 infection relative to HIV-1 infection in Guinea-Bissau. The author explores some ideas using results of prevalence and follow-up studies in infected population groups carried out by herself and her collaborators in Guinea-Bissau