Something for
you to read..
The epidemic of HIV and AIDS has attracted much attention both
within and outside the medical and scientific communities. Much of
this attention comes from the many social issues related to this
disease such as sexuality, drug use, and poverty. Although the
scientific evidence is overwhelming and compelling that HIV is the
cause of AIDS, the disease process is still not completely
understood. This incomplete understanding has led some persons to
make statements that AIDS is not caused by an infectious agent or
is caused by a virus that is not HIV. This is not only misleading,
but may have dangerous consequences. Before the discovery of HIV,
evidence from epidemiologic studies involving tracing of patients
sex partners and cases occurring in persons receiving transfusions
of blood or blood clotting products had clearly indicated that the
underlying cause of the condition was an infectious agent.
Infection with HIV has been the sole common factor shared by AIDS
cases throughout the world among men who have sex with men,
transfusion recipients, persons with hemophilia, sex partners of
infected persons, children born to infected women, and
occupationally exposed health care workers.
The conclusion after more than 20 years of scientific research is
that people, if exposed to HIV through sexual contact or injecting
drug use for example, may become infected with HIV. If they become
infected, most will eventually develop AIDS.
Where did HIV
come from?
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 at
http://www.niaid.nih.gov/newsroom/releases/hivorigin.htm.
