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| What is the history of AIDS? |
What is the history of AIDS?
Careful investigation has helped scientists determine where AIDS came from. Studies have shown that the human immunodeficiency virus first arose in Africa. It spread from primates to people early in the twentieth century, possibly when humans came into contact with infected blood during a chimpanzee hunt. By testing stored blood samples, scientists have found evidence of human infection as long ago as 1959.
Once introduced into humans, HIV was spread through sexual intercourse from person to person. As infected people moved around, the virus spread from Africa to other areas of the world. In 1981, U.S. physicians noticed that a large number of young men were dying of unusual infections and cancers. Initially, U.S. victims were predominately homosexual men, probably because the virus inadvertently entered this population first in this country and because the virus is transmitted easily during anal intercourse. However, it is important to note that the virus also is efficiently transmitted through heterosexual activity and contact with infected blood or secretions. In Africa, which remains the center of the AIDS pandemic, most cases are heterosexually transmitted. Twenty years ago, the news that Magic Johnson had acquired HIV heterosexually helped the country realize that the infection was not limited to men who had sex with men. Currently in the U.S., approximately 27% of new HIV infections are a result of heterosexual transmission.
In the years since the virus was first identified, HIV has spread to every corner of the globe and is one of the leading causes of infectious death worldwide. Statistics from the World Health Organization show that approximately 2 million people die each year from AIDS, and 250,000 of these are children. Worldwide, half of HIV-infected people are women. Two-thirds of current cases are in sub-Saharan Africa.
In the U.S., more than 1 million people are currently infected with HIV, and approximately 35,000 are newly diagnosed with AIDS each year. Over the years, more than 600,000 people in the U.S. have died from AIDS, many of them during what should have been their most productive years of life.
