Updated March 14, 1988 12:00 PM

Almost since the first recognition of AIDS in the U.S. in 1981, experts and the media have speculated about the threat it poses to heterosexuals. Initially, researchers considered the threat minimal. But by 1986 heterosexual transmission of the virus, usually from intravenous drug users to their sex partners, had become widely recognized, prompting fears of an explosion into the general population. U.S. News & World Report, for one, said AIDS had become “a plague of the mainstream.” Health and Human Services Secretary Otis Bowen, using the same analogy, cautioned that the “rapidly spreading” virus would eventually make the great plagues of history “pale by comparison.”

Today, however, AIDS experts are debating the significance of the fact that, as of February 1988, the much-feared epidemic spread of AIDS has not occurred. So far, according to most researchers, heterosexual transmission has been insidious but gradual and confined almost exclusively to the sex partners of intravenous drug users and bisexual men. In New York City, for example, 312 women have acquired AIDS through heterosexual sex, and virtually all are thought to have had direct contact with a member of a high-risk group. Nationally, according to the Centers for Disease Control in Atlanta, there are 1,643 AIDS cases, male and female, where the victim could not be shown to be a member of a risk group, or the sexual partner a member of a risk group. Those 1,643 “undetermined” cases also include people who would not co-operate with investigators, people who died before an investigation could be completed and those who simply didn’t know if they had been exposed to risk. Dr. Harold Jaffe, the CDC’s chief epidemiologist in the AIDS program, has said, “Those who are suggesting that we are going to see an explosive spread of AIDS in the heterosexual population have to explain why this isn’t happening.” Two months ago Secretary Bowen retracted his plague analogy and announced, “We do not expect any explosion into the heterosexual population.”

The key words are “explosion” and “heterosexual population.” Mathilde Krim, a research biologist and the outspoken co-founder of the American Foundation for AIDS Research, strongly believes that while the number of cases so far does not suggest an explosion, heterosexual transmission of the virus “can happen, and therefore it will happen, and the only thing we don’t know is at what rate it will happen. The infection will spread in the general population.” One of the frustrations faced by researchers is that although the CDC knows how many people have developed the disease, no one knows how many carry the virus, which can exist in the body for years before AIDS symptoms appear. The answer to that crucial question may come later this year, if CDC succeeds with its plan to test the entire student bodies of 10 to 20 universities and cross sections of the populations of 30 cities.

Randy Shilts, author of the best-selling history of AIDS in America, And the Band Played On: Politics, People and the AIDS Epidemic, is among those who think the threat to most heterosexuals has been exaggerated. “This is never going to be a middle-class disease,” Shilts says. “The whole media engaged in shameless hype about heterosexual AIDS. Now that it is not happening, no one will believe that there Is a threat.” The great threat Shilts sees, and which he claims the media are ignoring, is the rapid spread of AIDS among IV users and their sex partners. “There tea problem [with heterosexual AIDS], but it is a problem very specific to certain geographical and sociological groups, especially in New Jersey and New York. There is a level of infection in the Bronx that approaches that in Central Africa. AIDS is going to become a disease of the underclass.”

Perhaps the most controversial analysis of the low incidence of heterosexual AIDS cases outside the high-risk groups comes from Dr. Robert E. Gould, a New York psychiatrist, who contended in a January Cosmopolitan article that heterosexuals aren’t getting AIDS because it is very difficult to transmit the virus during “ordinary sexual intercourse,” which he defined as “penile penetration of a well-lubricated vagina—penetration that is not rough and does not cause lacerations.” Unless the virus can enter directly into a woman’s bloodstream—either through small tears in the vaginal wall or through the genital ulcers caused, for example, by venereal disease—vaginal intercourse, he argued, is very low-risk. “Some experts think that the virus can go through the vaginal mucosa [lining] and into the bloodstream, but they haven’t proved it,” says Gould. He believes that most of the U.S. AIDS cases attributed to heterosexual transmission involved anal sex—”a high-risk activity”—venereal diseases or lesions, or were misidentified. “My question is, If the virus can go through the vaginal wall or through microscopic lesions, then where are the numbers? There would be tens of thousands of women coming down with AIDS. But it’s been eight years now, and we’re not seeing this so-called explosion.”

Many researchers have been alarmed, to say the least, by Gould’s claim. “The article says don’t worry about it, go out and have a good time,” says the CDC’s Jaffe. “I think it’s completely irresponsible.” Dr. Michael Gottlieb, a Santa Monica, Calif., immunologist who has studied AIDS for eight years, echoes that sentiment: “Until more is known, it is frankly irresponsible to allege there is no risk. It has been clearly demonstrated that during vaginal intercourse there is microtrauma [abrasion] which may permit the virus into the bloodstream.” Shifts thinks that the barriers that have so far prevented wildfire infection are not biological—”statistics in New York give ample proof that AIDS can spread heterosexually”—but sociological: “How many girlfriends of black drug users have the social mobility to have sex with a professional man from the Upper East Side?” Krim believes that sociological barriers, if they exist, are temporary. “Little by little we’re going to see more cases of white heterosexuals with AIDS,” she says. “There are already some, but because of the stigma attached, the victims don’t want to disclose it.”

Given what we know now, how will AIDS progress in the U.S.? “I am almost certain there won’t be an explosion in the general population,” says Dr. Anthony Fauci, Director of the National Institute of Allergy and Infectious Diseases. “What we will be seeing—are seeing—is an increase in heterosexual cases, predominantly via the IV-using population.” Says Jaffe: “Over the next 5,10,15,20 years? I don’t think anybody knows. If you assume that the disease will become established in inner-city populations, the question is, Will it spread? Will there be sustained transmission into the general population? Some people have predicted that it won’t happen, others predict it’s inevitable. I don’t think we know.”

So what’s a single woman to do? “Thirty years old, living in New York, having three or four sexual partners a year?” asks Jaffe. “Is she really at risk? I think overall that her risk is very low. But it isn’t zero. It’s a risk you shouldn’t be willing to take.” His advice: “Limit your number of sexual partners, know people better before you have sex, and use condoms. We should be willing to do that to decrease our risk. But I don’t think there is a reason to panic.”