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The earliest known case of HIV-1 in a human was from a blood sample collected in
1959 from a man in Kinshasa, Democratic Republic of Congo. (How he became
infected is not known.) Genetic analysis of this blood sample suggested that
HIV-1 may have stemmed from a single virus in the late 1940s or early 1950s. We know that the virus has existed in the United States since at least the
mid- to late 1970s. From 1979-1981 rare types of pneumonia, cancer, and other
illnesses were being reported by doctors in Los Angeles and New York among a
number of male patients who had sex with other men. These were conditions not
usually found in people with healthy immune systems.
In 1982 public health officials began to use the term "acquired
immunodeficiency syndrome," or AIDS, to describe the occurrences of
opportunistic infections, Kaposi's sarcoma (a kind of cancer), and
Pneumocystis carinii pneumonia in previously healthy people. Formal
tracking (surveillance) of AIDS cases began that year in the United States.
In 1983, scientists discovered the virus that causes AIDS. The virus was at
first named HTLV-III/LAV (human T-cell lymphotropic virus-type III/lymphadenopathy-
associated virus) by an international scientific committee. This name was later
changed to HIV (human immunodeficiency virus).
For many years scientists theorized as to the origins of HIV and how it
appeared in the human population, most believing that HIV originated in other
primates. Then in 1999, an international team of researchers reported that they
had discovered the origins of HIV-1, the predominant strain of HIV in the
developed world. A subspecies of chimpanzees native to west equatorial Africa
had been identified as the original source of the virus. The researchers believe
that HIV-1 was introduced into the human population when hunters became exposed
to infected blood.
For more information on this discovery,
visit the NIH National Institute of Allergy and Infectious Diseases press
release.
For information on the theory that HIV originated in polio vaccines,
visit the CDC Vaccine Safety site. | 
