The Immunology of Hiv Infecton

Human immunodeficiency virus (HIV) infection is the worst pandemic to ravage the world since the Black Death. The Second Bubonic Plague, caused by Yersinia pestis, emerged from Central Asia in the mid-fourteenth century. Within a few years, between 25% and 50% of the people of Europe, North Africa and parts of Asia perished in its wake, and populations continued to decline into the latter half of the fifteenth century. HIV infection was first described in 1981 in homosexual men. Since then it has spread rapidly to become the leading cause of death in many sub-Saharan African countries. More than 25 million adults and children have already died and more than 42 million are currently living in the world with HIV/AIDS. Without effective prevention an additional 45 million people will become infected by 2010. South Africa is one of the worst affected countries. An estimated 4.74 million people or >11% of the population are currently infected.