They could not afford to jump to conclusions—any conclusions. Their only hope was to be grindingly, interminably thorough. Otherwise, they could pursue a course of investigation for hours or days, only to find it ended nowhere.
—The Andromeda Strain by Michael Crichton
The enemy is always time—an agonizing reminder of the suffering that can result from staying one step behind an elusive killer. At the outset of each new inquiry, they may not even know the description of their quarry, but its power is often all too evident. Along with old-fashioned legwork and intuitive insights, the specialists use the latest in scientific technology to compile and compare clues about nature's threatening puzzles. Such is the work, such is the mission, such are the stakes for America's disease detectives, whose special calling it is to track invisible killers, to identify mysterious illnesses that erupt from nowhere to menace life and health. Today an elite cadre of these experts—pathologists and epidemiologists, assisted by a larger army of lab technicians and doctors—are coordinating their skills in an effort to conquer a new threat: Acquired Immune Deficiency Syndrome, the confounding killer known as AIDS.
As of last week, there were 1,641 victims of AIDS, including 644 deaths, since it was first identified as a disease in the U.S. two years ago. Each month an average of 165 new cases is reported. The largest concentration of victims is in New York City (732 cases, 284 deaths). San Francisco has the next largest outbreak (160 cases, 54 deaths), followed by Los Angeles (100 cases, 40 deaths). AIDS is spreading, albeit slowly, to other nations; 122 cases have been reported in 17 countries.
AIDS attacks its victims by knocking out the immune system, thus leaving them defenseless against a host of "opportunistic" infections. A rare form of cancer or pneumonia becomes a deadly invader, but so does a fungus or a common virus. Thus far, there is no cure for AIDS and its source remains unknown. "We've looked at a lot of suspects," says Dr. Anthony Fauci of the National Institutes of Health (NIH), "but we have not come up with enough grounds for an indictment."
Asking questions. Hunting for clues. Testing theories. Hitting blind alleys. Asking more questions. The assault on the mystery of AIDS is a prime example of how disease detection works. The foundation has been laid by epidemiologists who have carefully analyzed the spread of the disease. So far, 75.9% of the victims in the U.S. have been active homosexual men, 16% intravenous drug users, 5% immigrants from Haiti, and 1% hemophiliacs. Only 96 victims so far are not known to be members of one of these risk groups. More than 90% of the victims are males between the ages of 20 and 49; young people account for just 1.3%. One cause for concern is that the incubation period of AIDS may be anywhere from six months to three years, and many people may have the disease without knowing it.