With federal funding deadlines looming, District Mayor Anthony A. Williams must decide soon whether to heed his public health advisers and begin compiling a list of residents infected with the AIDS virus--a move that would break a campaign pledge, infuriate the gay community and snub the D.C. Council.

For years, the city has put the names of people with AIDS and other infectious diseases in a confidential database. But it has never registered the names of thousands of D.C. residents who have HIV that has not yet progressed to AIDS.

Opponents of the plan want a "unique identifier" system, in which HIV cases would be logged into government computers with numbers instead of names.

Guided by policies of the U.S. Centers for Disease Control and Prevention, the city's AIDS chief, Ronald Lewis, wants the mayor to reconsider his 1998 campaign statements favoring the number system. Names reporting will yield the most accurate picture of an epidemic whose face has changed dramatically since erupting in the early 1980s, Lewis said.

The debate in the District has followed the same highly emotional script that has unfolded in state capitals over the past decade. Thirty-two states have adopted HIV reporting systems using names, while three are using numbers. Virginia reports with names; Maryland uses numbers.

Unlike the early years of the epidemic--when gay, white men represented the largest group of infected people--most of those being infected with HIV now are minorities, drug abusers or women. And with new treatments, infection with HIV no longer inevitably means a quick death.

"Even under the normal progression, it could take 10 to 15 years before turning into AIDS, and with drugs it could take forever," Lewis said. "This creates a huge vacuum of understanding about how this epidemic is taking hold in our community."

Lewis argues that the only way to avoid mistaken assumptions about who has contracted the virus and how they got it is to list by name.

But members of the D.C. Council and civil rights groups say a names system will worsen the epidemic by scaring large numbers of people away from being tested because of privacy concerns.

In a July 27 letter, 11 of the council's 13 members told Williams of their "extreme concern" about his willingness to consider a names-based system. Among those signing the letter was Jim Graham, former director of the Whitman-Walker Clinic, the region's largest AIDS service agency.

"There is overwhelming evidence that shows significant numbers of people avoid testing if their names will be reported," they wrote. "The end result is a dangerously skewed 'snapshot' of the epidemic that defeats the stated purpose of pursuing the policy in the first place."

The effectiveness of a new generation of lifesaving HIV drugs depends on starting therapy early. But about one-third of the estimated 750,000 Americans who are HIV-positive don't know they have the virus, and the top priority of epidemiologists is to get infected people tested and to a doctor.

Many in the HIV community fear the names will be leaked or become public in other ways and fuel discrimination by employers, landlords or insurance companies. Even if such fears may be unfounded, opponents of names reporting say that is irrelevant because public perceptions--whether realistic or not--determine whether people get tested.

Studies have shown that with names reporting some people will avoid being tested, but the rate varies widely from study to study.

AIDS activists express little faith in the ability of city officials to collect names confidentially and then make competent decisions about how to use that information to fight the epidemic.

"I would rather have government officials handing out condoms on street corners," said Wayne Turner, who heads the D.C. chapter of the AIDS rights group ACT-UP. "They're not doing their job in prevention, and so they're trying to shift the onus onto HIV-positive people."

Instead of names reporting, advocates are urging Williams to adopt a system in which each case would be filed under a code number, based partly on the patient's birth date and Social Security number. They say this would shield identities while allowing officials to complete counts and devise prevention and education strategies.

But supporters of names reporting say such data is subject to flaws, among them duplications when infected people are counted twice under two different IDs.

The mayor's policy director, Gregory McCarthy, acknowledged that Williams is facing a potential political backlash from the gay community, whose support the mayor sought last fall.

"During the campaign, he spoke favorably about the unique identifier system," McCarthy said. "Now, as the chief executive, he is doing due diligence to look at all the information available to him."

The mayor has been gathering opinions from health experts, epidemiologists, gay rights leaders and others, McCarthy said.

City hall observers say that if the mayor chooses names reporting, the council is likely to pass legislation mandating a number system.

Funding from the Centers for Disease Control is based on the number of HIV and AIDS cases. By 2002, states will be required to have CDC-approved counting systems to tally the number of residents with HIV and AIDS, or they will lose funding. The CDC prefers name-based counts but will accept well-run number systems.

To find out more about the two systems, Williams need look no farther than the Capital Beltway.

For 10 years, Virginia has required doctors and laboratories to report the names of everyone who tests positive for HIV. State officials say they are pleased with the results.

So far, leaders of the state HIV/AIDS community say they have not experienced serious problems or tried to change the system. "It, of course, has its flaws and vulnerabilities," said Kelly Eplee, executive director of AIDS/HIV Services Group in Charlottesville, "but I think it's fine the way it is just for the sake of tracking the epidemic and tracking services."

The widespread availability of anonymous HIV testing at 20 sites throughout Virginia has enabled people to find out if they carry the virus without the state knowing their names. But when they are tested by other labs or in a doctor's office, their names are sent to the state, Lea-Kruger said.

Maryland officials have been passionate advocates of the unique identifier system since they adopted it in 1994.

Maryland has been criticized over the accuracy of its data, but state officials say they have made great progress in improving reporting procedures used by doctors and laboratories. "We have absolutely no plans to change it," said Maryland AIDS director Liza Solomon. "Our experience looking at the Maryland data is that the people most concerned about confidentiality issues are the most high-risk people. . . . The very people you really are trying to entice into testing are the very people you are discouraging."

Several AIDS policy experts said they are confounded by the seemingly contradictory arguments made by opponents of reporting names. With the support of AIDS activists, six states and the District are now considering Medicaid rules to permit any low-income person with HIV to gain coverage for the expensive antiviral therapy.

"If we say they should be on Medicaid, then we're letting one state or city agency have the names but not another; that on its face is a little absurd," said Jeff Levi, a George Washington University health policy researcher and former deputy director of the Office of National AIDS Policy.

As soon as an HIV patient seeks treatment from any doctor or drugs from any pharmacy or Medicaid coverage, secrecy is gone, Levi said. "Everyone would acknowledge that public health departments' ability to maintain confidentiality are far better than that of the traditional health-care system," he said.

But those opposed to names reporting deny their arguments are contradictory.

"No one is forcing you to apply for or accept Medicaid," said Matt Coles, director of the ACLU's National AIDS Project. "But the test issue is different. It says if you get tested, we will report your name to the government. Therein lies our problem with reporting."