Africa was long characterized as the “dark continent,” impenetrable, disease-ridden, and dangerous. To many Europeans, Africans personified degeneracy and suffering, and their environment seemed a hothouse of fever and affliction. Europeans had good reason to connect sub-Saharan Africa with disease. For centuries, their attempts to penetrate the coastal fringes of the continent had been effectively frustrated by diseases against which they had little or no resistance (Carlson 1984). In the early nineteenth century, Europeans arriving in West Africa suffered appalling mortality from disease (most often yellow fever and hyperendemic malaria) at rates of between 350 and 800 per 1,000 per annum (Curtin 1968), and the West African coast became known as the “white man’s grave.” With such mortality rates, it is no surprise that Europeans believed that Africa was more disease-ridden than other parts of the world.

In fact, many continue to believe that tropical Africa has a well-deserved reputation as a vast breeding ground and dispersal center for dozens of diseases and thus would subscribe to the recent assertion that “Africa is a sick continent, full of sick and – starving people” (Prins 1989). This view has been reinforced by scientific speculation concerning the appearance of so-called exotic new diseases like Ebola, Marburg, and Lassa fevers in the 1960s and 1970s (Westwood 1980; Vella 1985). The HIV viruses that cause the acquired immune deficiency syndrome (AIDS) are the most recent additions to this list. Recent technological advances, especially in electron microscopy, coupled with the rapidly expanding specialties of molecular biology, genetics, and immunology, have given rise to an equally rapid expansion of virology