|
Where did
HIV come from?
We do not know. Scientists
have different theories about the origin of HIV, but none have
been proven. The earliest known case of HIV was from a blood
sample collected in 1959 from a man in Kinshasha, Democratic
Republic of Congo. (How he became infected is not known.) Genetic
analysis of this blood sample suggests that HIV-1 may have stemmed
from a single virus in the late 1940s or early 1950s.
We do 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 gay male patients. 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, and Pneumocystis
carinii pneumonia
in previously healthy men. Formal tracking (surveillance) of
AIDS cases began that year in the United States.
The cause of AIDS is a virus
that scientists isolated in 1983. 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). |
