(3 of 8)
As the mystery deepened and the number of cases rose, the CDC intensified its investigation into the causes of the syndrome. Disease detectives interviewed scores of homosexuals about their sexual practices to test the hypothesis that AIDS was somehow tied to the gay life-style. They briefly considered and then discarded a theory linking AIDS to the use of "poppers" (liquid inhalants like amyl nitrite and butyl nitrite), which are said to enhance sexual pleasure and which had been used by many of the victims. Another theory held that repeated anal intercourse introduced sperm into the blood-stream and that this could cause profound immune suppression. Then there was the "immune-overload theory," which was based on the fact that many early AIDS patients were extremely active sexually, with hundreds of partners over the course of their lifetimes and long histories of venereal diseases and infections. Under the accumulated burden of so many infections, the overload theory suggested, their immune systems had simply given up.
But most of these explanations were abandoned as evidence grew that AIDS was caused by an infectious agent that could be passed from one person to another through sexual contact or in body fluids. The evidence included a "cluster" of nine patients in and around Los Angeles; each had had sex with people who later developed AIDS-related diseases. It was bolstered by the growing number of intravenous drug users infected by the disease. Addicts share germs when they share needles. Then came the clincher: cases of AIDS in hemophiliacs and later in recipients of donor blood. The pattern resembled that of hepatitis B, a blood-borne and sexually transmissible virus that is common among drug addicts, blood recipients and gay men. AIDS cases among Haitian men and women remained a puzzle until it was discovered that many of the men, though not homosexually inclined, had warded off destitution by serving as prostitutes to gay men. Earlier this year, Haitians were dropped by the CDC as a separate risk category for AIDS.
The discovery of the AIDS virus came much sooner than anyone could have expected. "We have never made such rapid progress with any disease in the past," says Margaret Heckler, Secretary of Health and Human Services. It was in May 1983 that a French team led by Dr. Luc Montagnier of the Pasteur Institute in Paris first published evidence of a new virus that appeared to play a role in the disease. The following spring, Dr. Robert Gallo of the National Cancer Institute in Bethesda, Md., announced that he had conclusively identified the AIDS virus and produced it in large quantities. At a press conference that many scientists felt undercut the important contribution of the French, Heckler hailed Gallo's achievement: "Today we add another miracle to the long honor roll of American medicine and science." Her fulsome statement added fuel to a smoldering rivalry over who deserves credit for the discovery.
Though AIDS sufferers have yet to benefit from the Franco-American "miracle," research on the virus has shed considerable light on the nature of their disease and why it so devastates the immune system. The virus launches a direct attack on helper T cells (or T lymphocytes, as they are also known), invading them in much the same way that the hepatitis virus homes in on cells in the liver. Once ensconced in the T cell, explains Dr. Clifford Lane of the National Institutes of Health, the AIDS virus prevents this vital cell from doing its job as "the initiator of all the immune-system response." Says Lane: "It turns the T cell off from being a lymphocyte and on to being an AIDS-virus factory."
See TIME's Pictures of the Week.