Origins of the HIVs and the AIDS Outbreaks

Abstract

Abstract The AIDS pandemic was caused by human immunodeficiency virus (HIV) type 1 group M (HIV‐1M). It is not widely appreciated that there are three other HIV outbreaks that emerged independently in different regions of Africa during the last century. To date, 13 HIV groups have been discovered, but only four of which became major outbreaks to varying degrees. HIV‐1M is responsible for 90% of over 35 million deaths, and the other three epidemic HIVs are estimated to have infected from 25 000 to 750 000 people each. A handful of key determinants explain how and why this happened, including human interaction with the simian sources from which the HIVs emerged, but much more important were new ways that people spread the viruses to one another. The latter included population movement and urbanization, changes in sexual relations, war, and above all new medical procedures (unsterile needles and inadequately tested blood transfusions). The emergence of the viruses and their epidemic spread was not the result of a random mutation but rather depended upon the combination of specific circumstances at different places and times. The AIDS pandemic was not a chance, natural occurrence; it is much more accurately described as a (hu)man‐made disaster. Key Concepts The global AIDS pandemic was caused by multiple human immunodeficiency viruses. The HIVs emerged from different simian immunodeficiency viruses (SIVs) independently in two widely separated regions and at different times, mainly during the early and mid‐twentieth century. Broader understanding of historical, social, and cultural circumstances is necessary to explain how and why these viruses emerged and became pandemic. The most important new circumstances causing the emergence of HIV epidemic viruses in the twentieth century were those that facilitated passage of pathogens between humans. In addition to population movement, urbanization, and changing sexual relations, the most ubiquitous new developments increasing the possibility of adapting viruses to humans were blood transfusions and injections against diseases or for mass vaccination campaigns with insufficiently sterilized needles which were contaminated with as yet undiscovered viruses.