Not long ago, driving on an interstate highway, we were listening to the radio when a man on a request line asked that a love song be dedicated to ''Tony.''

The disc jockey shot back: ''I hope that's 'Toni' with an 'i.' '' The man on the phone quickly assured the DJ that his loved one was indeed female.

Such talk on the airwaves might seem inconsequential. It's not. The reinforcement of timeworn prejudices has deadly results.

''Stigma and discrimination are the enemies of public health,'' says Dr. Jonathan Mann, director of the International AIDS Center at Harvard University. He has written the preface to an important new report -- ''The Impact of Homophobia and Other Social Biases on AIDS'' -- released by the Public Media Center based in San Francisco.

Though media coverage has slacked off during the last several years, the AIDS crisis has not. On the contrary: Among Americans between the ages of 24 and 44, AIDS is now the leading cause of death. Worldwide, more than 17 million people have died from the disease.

''Our nation is suffering in the midst of an unprecedented public health emergency in which more than a million Americans may be diagnosed with AIDS by the year 2000 -- nearly one out of every 250 Americans,'' the report notes.

''Yet, as a nation, we continue to work in the dark, without fully implementing a national AIDS plan, without a concerted national commitment to conquering the AIDS crisis and without sufficient public or private resources to deal with the issue.''

Ask yourself: If, 15 years ago, a cross-section of the American people had become infected with AIDS via heterosexual intercourse, would the federal government have been so slow to respond? And would anti-AIDS endeavors still be so low on the agendas of elected officials and mass media?

In the early 1980s, AIDS became known as a disease afflicting gay men. Since then, AIDS has spread widely, hitting the poor especially hard. Boosted by intravenous drug use, the illness is killing large numbers of blacks and Latinos.

''Irrational prejudices like homophobia have obstructed public health efforts that prevent the spread of AIDS,'' the Public Media Center points out. The stigma attached to AIDS is a ''social pathology that distorts public policy, fuels infection and subverts AIDS care.''

These days, it's true that we're likely to see quite a few laudable, empathetic news stories about people with AIDS. We're also apt to see in-depth scientific articles about AIDS research in the mainstream press.

But an AIDS crisis with a terribly urgent need for much more effective countermeasures? Judging from routine media coverage, such a crisis does not exist.

The nation's persisting failure to confront the AIDS epidemic is directly linked to anti-gay prejudices, as the new report makes clear:

''Despite the fact that numerous 'risk groups' have been associated with HIV/AIDS, the disease has maintained its greatest hold on the public imagination in terms of its connection to gay and bisexual men.

This perception coincides with an underlying and prevalent homophobia.''

The obstacles to effectively mobilizing against AIDS are especially difficult ''because homophobia has never been addressed through an open, public dialogue, and because a social consensus condemning homophobia has never been formed.''

Anti-gay prejudices, combined with a common view of AIDS as a gay disease, ''continue to hamper our efforts to address this as a health crisis not only for gay and bisexual men but for women, for people of color, for intravenous drug users and for other populations.''

The report urges Americans to ''address homophobia as an independent moral issue involving the goals of fairness, human dignity and the promotion of social tolerance and understanding.''

Clearly, wide implementation of preventive measures will be necessary to stop the AIDS epidemic. Even now, however, news media provide sparse information.

If only the major media outlets were as good at informing the public about AIDS prevention as they are at informing us about superficial events in the lives of Hollywood celebrities. Halting the spread of AIDS will require ''continual'' and ''pervasive'' messages encouraging protective behavior, the Public Media Center report concludes. AIDS is an ''indiscriminate killer that we allow to thrive only as a result of our own uncon- fronted prejudices, fears and ambivalence.''

By confronting our own prejudices, we can turn away from ambivalence -- and move toward determination to end the AIDS crisis.