Study Confirms AIDS Began in AfricaBy Cynthia Kirk
This is Bill White with the VOA Special English SCIENCE REPORT.
A new study says the disease AIDS began in Africa in the Nineteen-Thirties, long before it was recognized as a disease. The study confirms earlier studies suggesting a direct link between HIV, the virus that causes AIDS, and chimpanzees in western Africa.
American scientists made the discovery using one of the world's most powerful computers. The research was done at the Los Alamos National Laboratory in New Mexico. It appeared in the publication "Science."
Scientists estimated when the AIDS crisis started by using a powerful computer model. Researchers studied how quickly the virus changed over time, using HIV genetic information. The information was then used to develop a family history of HIV.
The earliest evidence of HIV was found in the blood of a man from what is now Congo-Kinshasa in Nineteen-Fifty-Nine. But scientists say the disease has been around much longer. Current evidence suggests that HIV first developed from a virus carried by chimpanzees in southwestern Africa between Nineteen-Ten and Nineteen-Fifty. Scientists say the Nineteen-Thirties is the most likely period.
Scientists say the most common form of HIV developed from simian immunodeficiency virus, or SIV. SIV is a disease found in chimpanzees. Some scientists believe the first case of HIV infection happened after a chimp bit and infected a human. Others say SIV genetically changed to HIV either while it was in the chimp or after a human was infected with SIV.
Scientists believe the virus stayed in a very small population in Africa at first. Then it spread around the world because of increased sexual activity, airplane travel and big cities.
Some researchers have suggested that a vaccine to prevent the disease polio in the late Nineteen-Fifties can be blamed for the increase of AIDS. They say the polio vaccine made from chimpanzee kidney cells could have passed HIV to people. However, other scientists say it is not likely that the polio vaccination campaign led to the increase in AIDS.
More than thirty-three-million people around the world are infected with HIV or suffer from diseases caused by AIDS. The majority of people with HIV live in developing countries. More than sixteen-million people have died since the AIDS crisis began.
This VOA Special English SCIENCE REPORT was written by Cynthia Kirk. This is Bill White.