HIV/AIDS, Geography of

The virus that causes acquired immune deficiency syndrome (AIDS), or acquired immunodeficiency syndrome, was first identified by scientists in 1983. Since then, the geographic origins of the virus have been hotly debated in the scholarly and secular communities. Recent studies by genetic scientists have indicated that HIV-1, the more virulent form of the virus that causes AIDS, can be traced to a closely related strain of virus, called simian immunodeficiency virus (SIV), that infects a subspecies of chimpanzees in Central Africa. It also happens that people in this region hunt chimpanzees for bush meat, leading scientists to believe that the virus may have passed from the blood of chimpanzees into humans through superficial wounds. Indeed, many believe that the virus has been prevalent among humans in remote, inaccessible jungle areas since the 1920s. However, in today's globalized and highly interconnected world, the virus somehow managed to escape from this region into the wider world. There are two forms of this virus, HIV-1 and HIV-2. HIV-2 is restricted to the Guinea Highlands of West Africa, while HIV-1 accounts for the majority of AIDS cases throughout the world.

UNAIDS (Joint United Nations Programme on HIV/AIDS) estimates indicate that the number of persons living with HIV worldwide was 33.2 million in 2007. However as shown in Figure 1, sub-Saharan Africa continues to be the region by far most affected by the AIDS pandemic. In 2007, out of the 33.2 million people infected with HIV, 22.5 million were in sub-Saharan Africa. An additional 1.7 million people were infected with HIV during that year. During the same year, over 1.6 million people were estimated to have died from this syndrome in Africa. It is estimated that more than two out of three (68%) adults and [Page 1437]nearly 90% of children infected with HIV live in this region, and more than three in four (76%) AIDS deaths in 2007 occurred there, illustrating the unmet need for antiretroviral drugs. In the 10 worst-affected countries, all of them in Eastern and Southern Africa, rates of HIV infection range from 16% to over 40%.

Figure 1 Adults and children estimated to be living with HIV in 2007

Sources: Joint United Nations Programme on HIV/AIDS (UNAIDS) & World Health Organization (WHO). (2007). 2007 AIDS epidemic update (p. 39). Geneva: UNAIDS. Retrieved January 20, 2010, from the UNAIDS Web site: http://data.unaids.org/pub/EPISlides/2007/2007_epiupdate_en.pdf. Reprinted by permission of UNAIDS.

With reference to the geographic spread of the epidemic in Africa, John Iliffe, in his 2006 book titled The African AIDS Epidemic, masterfully synthesizes the plethora of studies that have been conducted from the 1980s to the present, tracing the geographic beginnings and spread of AIDS throughout the continent. Iliffe weaves together a fascinating story that attempts to explain the origins, nature, and spread of the virus from its detection in the early 1980s to its current progression throughout the continent. He places the origins of the disease somewhere in present-day Central Africa, from where it spread slowly to East Africa. Several other studies that have examined in greater detail the spatial-temporal trends of AIDS in Africa during the past 25 years show an escalating epidemic in Southern Africa and signs of a stabilizing or declining epidemic in East Africa. At present, Southern Africa remains the worst affected region in the world, with HIV prevalence rates in excess of 25%. Data in these detailed studies lend credence to the saying that “there is not just one epidemic in Africa, but [Page 1438]many.” West Africa and North Africa have consistently experienced lower rates than the other regions, although in some countries in West Africa, the epidemic is creeping up. Even within the other high-risk regions in Central, Eastern, and Southern Africa, some areas have lower rates than others. Thus, it is not just between countries that there are differences in the prevalence of HIV/AIDS, but there are differences between different areas and different groups of people within the same country. In spite of the spatial variations, the epidemic in Africa is largely driven by unsafe sex between men and women.

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