A new and dangerous battle is brewing over federal AIDS policy.

According to published reports, the U.S. Centers for Disease Control may soon issue guidelines calling for forced HIV testing of health workers who perform invasive procedures and for barring those who test positive from continuing to perform them. This would dramatically shift CDC policy, which now asks infected workers who perform invasive procedures to identify themselves to their institutions and to their personal physician for individual evaluation. These changes are opposed by leading medical and public health organizations.

According to a consensus statement signed by 12 such organizations, "The best scientific information ... does not support routine restriction of ... HIV-infected health care workers from performing invasive procedures." Transmission of HIV from infected health workers to patients, they maintain, "must be an exceedingly rare event, if it occurs at all." Indeed, 10 years into the epidemic, with more than 5,800 cases of AIDS reported among U.S. health care workers, there is not one scientifically documented case of HIV transmission from health worker to patient. Four studies have followed up patients of surgeons who had died from AIDS without identifying a single patient who had become infected as a result.

The sole basis for the proposed change in CDC policy appears to be a lone highly publicized case of possible transmission of HIV from a Florida dentist to a patient. The case is troubling, but still under investigation.

Some have proposed that all infected health workers should be restricted if even one life could be saved by doing so. We must consider, however, the enormous social costs of such a move as well as the purported benefits. These costs would include:

1) HIV Patient Dumping. As infected health workers lose their jobs, uninfected ones will view patients with HIV as threats not only to their health but also to their employability. More surreptitious HIV testing and dumping of "high risk" and infected patients are sure to follow.

2) Diminished Medical Care for the General Public. Forcing out thousands of skilled health workers would sharpen America's shortage of health workers, deprive patients of substantial medical expertise and reduce our ability to provide quality medical care. Areas of high AIDS incidence would be hit especially hard as some health workers would avoid practicing in cities where the risk of becoming infected by patients was seen as substantial. As a result, many lives could be endangered.

3) Increased Financial Costs. Society's investment in the training of thousands of health workers would be lost, and new resources would be needed to train replacements. Health care costs would increase -- to patients and third-party payers -- as a result of employment discrimination lawsuits.

4) Undermining of Health Workers' Rights. Restricting HIV-infected workers on the basis of a remote and still theoretical risk would logically dictate restricting health workers with other conditions that could conceivably result in harm: hepatitis, poor sleep habits, stress, depression, social drinking or even genetic defects. If, as some suggest, patients have a "right to know" that their doctor is seropositive for HIV, may they not also ask how often their dentist drinks alcohol or whether their surgeon has been in therapy -- and why?

5) Threat to Privacy, Employment Rights in General. The CDC draft proposal, if implemented, would invite a range of employers to institute testing and discrimination programs for other small or speculative risks. This would open the door not only to broad-scale workplace testing for HIV but also to drug, alcohol, genetic and other testing.

6) Weakened Legal Protection for the Disabled. Recent federal law prohibits discrimination against people with disabilities, including HIV, based upon "speculative or remote risk." Discrimination is permitted only when there is "a significant risk to the health or safety of others that cannot be eliminated by reasonable accommodation." These legal standards would be eviscerated if the CDC HIV proposal were upheld in court under current medical evidence.

7) Undermining of Government AIDS Programs. Basing government AIDS policy upon fear instead of reliable medical evidence would undercut the credibility of other government AIDS prevention efforts. As health experts seemingly disagree about the potential for doctor-patient transmission of HIV, official assurances that other contact with infected individuals is safe may be increasingly disbelieved. Moreover, a CDC-backed testing and discrimination program would enhance the climate of fear that blocks high-risk individuals from seeking voluntary testing, counseling and treatment.

8) Shattering the Lives of Infected Individuals. The CDC proposal would devastate thousands of infected workers and their loved ones. In addition to their inevitable medical distress, these individuals would face problems of unemployability, financial catastrophe, loss of confidentiality, public stigmatization, isolation and diminished self-esteem.

Given the lack of evidence of any significant transmission of HIV from health workers to patients, the cost of the CDC proposal clearly outweighs its purported benefits. But that doesn't mean that the CDC should stand still. It should collect more data to determine what, if any, risk is posed by infected workers performing specific procedures and compare this with other known health care risks. It should provide long-overdue leadership in developing equipment and techniques that reduce the potential for blood-to-blood exchange between health workers and patients. And it should do everything in its power to encourage all health workers to increase compliance with infection control guidelines. This would not only protect patients from AIDS -- and other illnesses -- but also protect health workers as well.

Benjamin Schatz, a lawyer, directs a project for doctors with HIV conducted by the American Association of Physicians for Human Rights in San Francisco. Alvin Novick is a doctor and professor of biology at Yale.