The Relationship Between the Human Immunodeficiency Virus and the Acquired Immunodeficiency Syndrome: Executive Summary (Draft)

DRAFT

23. Baboons develop AIDS after inoculation with an HIV variant that also
causes AIDS in humans.
Over the course of two years, baboons infected with HIV-2 exhibited a significant decline in immune function, as well as AIDS-like symptoms.
24. Asian monkeys develop AIDS after infection with the simian immunodeficiency virus (SIV), a virus closely related to HIV.
In macaque species, various cloned SIV isolates induce syndromes that parallel
HIV infection and AIDS in humans, including swollen lymph nodes early in
infection and the occurrence of opportunistic infections such as PCP and MAC.
25. HIV has been repeatedly isolated from the semen of patients with AIDS, a
finding consistent with the epidemiologic data demonstrating AIDS
transmission via sexual contact.
26. HIV has been isolated from the brains of children and adults with AIDS,
which helps explain the central nervous system disorders seen in many
patients with AIDS.
RESPONSES TO CRITICISMS THAT HIV IS NOT THE CAUSE OF AIDS
1. HIV cannot be the cause of AIDS because researchers are unable to explain
precisely how HIV destroys the immune system.
By this reasoning, Mycobacterium tuberculosis is not the cause of tuberculosis
(TB), nor hepatitis B virus a cause of certain types of human hepatitis. The
disease-causing mechanisms of many diseases, including TB, hepatitis B and
polio at the time it was contained, are poorly understood. A complete
understanding of the pathogenesis of a disease is not a prerequisite to knowing
its cause.
2. Behavioral factors such as recreational drug use and excessive sexual behavior
or the immunosuppressive effects of transfusions account for AIDS.
The proposed behavioral causes of AIDS, such as promiscuity and excessive
drug use, have existed for years. The epidemic of AIDS, characterized by the
occurrence of formerly rare opportunistic infections such as PCP did not occur
in this country until a previously unknown human retrovirus -- HIV -- spread
through certain communities.
Compelling evidence against the hypothesis that behavioral factors cause AIDS
comes from recent studies that have followed cohorts of men for long periods of

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