AIDS is someone else's problem. At least it would seem so from the curious split between public attitudes and private actions on the part of many Americans. There is great concern about casual transmission of this disease, but when people climb into bed or the back seat of a car there is a sense of otherliness. Informal surveys of sexual behavior reveal considerable anxiety but surprisingly little change.

The bulk of cases so far have been from minorities of one sort or another. Homosexuals and heroin users are subpopulations in the United States, both of them objects of considerable disapprobation and little sympathy. Additionally, intravenous drug users come largely from the so-called underclass and are most likely to be black or Hispanic.

The majority of young people simply do not picture themselves as likely to have sexual contact with members of these groups or with anyone who has had intercourse with them. The small but rapidly rising number of cases in infants and non-drug-using women are largely among racial and social minorities because of the distribution of i.v. drug abuse.

None of the groups initially afflicted with AIDS is close to the corridors of power, and they have been at best able to attract attention as noisy outsiders and as a threat to the general well-being. Although the body politic has been slow to respond, the Congress is now pumping substantial sums into research, care and education, with considerable sensitivity to the civil rights of those afflicted. But there are hundreds of restrictive bills churning through state legislatures, many of which are clearly not meant to apply to the lawmakers or their families but to others.

Meanwhile, health officials have contributed to this sense of the disease being elsewhere by correctly but tendentiously stating that there has been no sign so far of "breakout" into the "general population." Attention to this technically correct but humanistically oblivious point dulls the sense of urgency about the problem. For example, two different groups of young military recruits, tested 18 months apart, were found to have the same infection rate for AIDS. This was seen as encouraging because the worst predictions had not been borne out. But that flat rate was really for a new group of sexually active recruits, adding to the pool of disease carriers.

It has been unequivocally clear in Africa, and now in Latin America, that acquired immune deficiency syndrome is spread from male to female or female to male by ordinary sexual intercourse. The risk may not be as great as with other forms of transmission. It may be greater for the female. The general health and immune system status of a population may be factors. But the pool of infected persons in the United States is growing; and the infectiousness of those incubating the disease is rising. The assumption that the world-wide dominant route of spread of this disease will not become a major one in the U.S. is a thin thread by which to hang public policy.

The time curve of risk for the larger population may have been shifted by these findings to the right, which is only to say a few years further into the 1990s. It requires academic gymnastics of a high order to avoid the obvious conclusion that most of the factors for spread into the general population are in place.

New relationships are constantly being formed and consummated by the tens of thousands. The inherent intimacy and privacy of sex, even casual sex, tends to exclude the outside world. Potential consequences seem remote indeed, as measured by centuries of unwanted pregnancies and venereal disease -- when nothing could be done about either of them. Weighing a risk whose consequences are so dissociated from the act is tough.

In addition, the attention span of the public is notoriously short and fickle; no issue seems to sustain interest for more than a few months. The video age, with its quick snippets of information, staccato shifting of images and discordant transitions, may have accentuated the normal human impulse to deny and move on. We are more accustomed to quick solutions than to sustained effort. People are already tired of hearing about AIDS; it has become one of those things that are just there, that people feel they cannot keep thinking about. They are becoming desensitized.

There have been four waves of public interest in AIDS, each of which has lasted a few months and then gradually subsided. Initial media coverage in 1981 was tentative, since there were only a handful of curious cases, which did not seem to merit much comment. Each subsequent wave of attention, coming at approximate two-year intervals, has been more intense and sustained than the previous surge.

The current one began early this year. It has swelled with the steady increase in cases and the emergence of a panoply of tough ethical, legal and financial questions. Schools and public health agencies are gearing up major educational efforts to modify behavior, against a background of the limited success of such recent efforts as smoking cessation and the reduction of fats in the diet.

The institutionalization of concern about this disease will prevent the current surge of awareness from fading, but the major challenge remains: to motivate individuals to personalize what they hear. This is clearly one case where learning by experience will be too late. It may be that most people will fail to grasp the essence of this hazard until they personally know, rather than know of, someone afflicted. By that time the genie will really be out of the bottle and the term "breakout" will have been changed to "break-in."

The story of AIDS now has so many subsidiary issues as to distract attention. Politics, religion and sex are a powerful mix, and each is easier to deal with in the abstract. With such complex issues and with so many changes in our understanding of the disease, it is easy to become confused about what is and is not significant. It would be sad indeed if people were to let down their individual guard, be lulled into a false sense of security by the otherliness of this disease, and fail to do what is already well-known about prevention.

J.D. Robinson, MD, is a physician and essayist in Washington.

Second Opinion is a forum for points of view on health policy issues.