The Origin of HIV

Scientists have developed many different theories about the origin of HIV, but none of them have been proven. HIV is a human virus that is closely related to simian immunodeficiency virus (SIV), a virus that infects chimpanzees and monkeys. SIV has been a known virus in monkeys for thousands of years and does not cause illness in these primates. Studies about the evolution of HIV have estimated that SIV passed from monkeys to humans approximately 80 years ago in the 1930's. It is speculated that human hunters first became infected with the virus after coming into contact with the blood of the monkeys that they had killed for food. In 1999, an international team of scientists confirmed that a chimpanzee native to west equatorial Africa carried a form of SIV which was nearly identical to an aggressive form of HIV. It appears that chimpanzees were the source of HIV, and that the virus somehow crossed species from the chimpanzees to humans. It is not clear when this happened, but there have been reports of HIV infection since the middle of the twentieth century. The earliest known case of HIV in a human was a man in Kinshasa, Democratic Republic of China. Analysis of his blood sample suggested that HIV may have developed from a single virus in the late 1940's or early 1950's.

HIV has existed in the United States since the mid-to late 1970's, when men who had sex with other men were being diagnosed with rare types of pneumonia, cancers, and other unusual illnesses which did not normally occur in people with healthy and intact immune systems in Los Angeles and New York City. In 1982, public health officials began to call this syndrome of opportunistic infections, Kaposi's sarcoma, and Pneumocystis carinii pneumonia in previously healthy men "acquired immunodeficiency syndrome", or AIDS. Formal surveillance of AIDS cases by the U.S. government began in 1982.

HIV, the virus that is known to cause AIDS, was isolated in humans by scientists in 1983; the virus was initially named LTLV-III/LAV. The name was later changed to human immunodeficiency virus (HIV).

HIV started to infect humans and quickly became an epidemic in the middle of the twentieth century. International travel is a key factor that facilitated the movement of HIV from epidemic to pandemic. Even today, the debate over the exact origin of HIV continues. Perhaps it would be more beneficial to the millions of people worldwide who are infected to put that energy and research into how we can better treat existing cases of HIV and AIDS and prevent new infections from occurring.