From a mysterious disease that appeared in the United States in the early 1980s, HIV/AIDS grew into a global scourge with death tolls in the millions. Its deadly impact on populations such as gay males and the poor of Africa has made it one of the most politically contentious diseases of the last century. The HIV/AIDS Pandemic explores the causes, the spread, the effects on people's lives, as well as efforts to treat the disease and halt its spread.