Aids stalks the continent of africa, but isn"t confined to it. It is a global disease and the 1st pandemic of the 21st century. It is a deadly disease for which there is no cure or vaccine. The threat of polio and smallpox are nonexistent because of effective vaccines, and diphtheria, whooping cough are rare because children are immunized with dpt shot. Aids transcends economies, and according to the who it afflicts 15 million people worldwide and occurs in both developed and less developed countries. Worldwide estimated that 12. 9 million were infected, 20 years later 30-40 million people were infected and 18 million died from aids. Aids began as most epidemics do with small number of cases, fewer # of deaths and almost geometric increase in # of cases and deaths. Virus that causes aids is called human immunodeficiency virus [hiv] .