AIDS remains a dreadful, and to date, universally fatal infection. People are very afraid of AIDS - and they should be.

Science has vastly increased our knowledge of AIDS and has given us exquisitely accurate tests with which to detect the presence of HIV infection. The wide use of the HIV antibody test not only assures us of a safe blood supply but enables us to treat patients even before symptoms surface.However, because of the stigma so tenaciously associated with this infection, the HIV test has become a double-edged sword. Cruel discrimination rides on the back of the blade.

The possible transmission of HIV from one infected dentist to one of his patients, and the recent AIDS-related death of a Baltimore surgeon (who apparently was infected by one of his patients) has set in motion a wave of worry that threatens to result in new guidelines from the Centers for Disease Control.

Health-care providers - particularly doctors and dentists - would be tested for HIV infection. Those testing positive may be forced to limit patient care activities.

At first glance such a proposal seems reasonable. Our physician oath dictates that physicians should do no harm. Long and arduous training, certifying exams, licensing, hospital peer review and the like are all efforts to assure this. But for at least two reasons, screening all physicians for HIV infection will not necessarily accomplish this goal.

First, although the risk of possible transmission of HIV infection from a physician to a patient has always been acknowledged, nearly 10 years down the pike it has never been convincingly documented. The risk of such transmission is not zero but is too low to calculate. Thus a policy to screen health-care providers would grossly distort this small risk and may actually emphasize it over and above other risks that health-care professionals more commonly visit upon their patients.

Second, it will encourage physicians to shy away from another tenet of ethical medical practice stated clearly as policy since the 19th century: "When an epidemic prevails, a physician must continue his labors without regard to the risk of his own health." Alas, avoidance of the HIV-infected is happening already.

Future physicians are selecting medical schools and training programs away from cities with the highest prevalence of HIV infection and there is evidence that some health professionals in those cities may already be pulling out. This proposed branding will hasten the crumbling of health care available to those in greatest need: those already HIV-infected and the inner-city poor who live in areas with the highest rates of HIV infection in the United States.

The HIV test, which measures a person's antibody response to the virus, is among the most accurate in clinical medicine. Yet, it may take several months before it turns positive after the infection has taken root.

While such test results are in limbo, should a surgeon who is cut during a procedure (once in every 40 cases) sit out until "certified infection-free"?

The message to health professionals will be clear: "To continue to care for your patients, and to use your precious skills which required years of training to obtain, don't take care of the HIV-infected, or those who you think might be."

The negative consequences will far outweigh a doubtful reduction in risk. In a world that already seriously undervalues and trivializes service to others, this will compound the tragedy of AIDS.