Migrant labor and sexually transmitted disease: AIDS in Africa.

Acquired immune deficiency syndrome (AIDS) is worldwide, but the clinical and epidemiological pattern of the disease in Africa is different from that in developed areas. "Type 1 AIDS" occurs in industrialized North America and Europe; it has a distinctive sex ratio (16:1) and risk pattern of IV drug use and sexual practices. "Type 2 AIDS" occurs in Third World countries, particularly in eastern, southern, and central Africa. It is characterized by an entirely different sex ratio (1:1) and by distinctively different risk patterns. Both epidemics are caused by the HIV-1 virus. The key concept for understanding the origins of the differences between Type 1 and Type 2 AIDS is the migratory labor system in eastern, central, and southern Africa. This system causes long absences, increased family breakdown, and increased numbers of sexual partners. Historically the organization of this labor market has created a population which suffers from epidemics of sexually transmitted diseases. These historical patterns are presented as evidence for the contemporary transmission of AIDS. When contemporary AIDS and HIV-1 seropositivity prevalence data are examined, a systematic temporal and geographic pattern emerges for the AIDS epidemic in Africa. Despite a paucity of good data, the prevalence data from eastern, central, and southern Africa support the thesis of migrant labor's role in the transmission of AIDS.