Since AIDS was first identified in 1981, its rate of spread among a primarily young and vibrant population has chilled the medical and lay communities. Today, the public response is sober and oriented toward the examination of specific policies that could lessen the impact of the disease. After six years' experience it is now feasible to propose a strategy for combatting AIDS. Consensus around the following policies should form the nucleus of the public health strategy to combat AIDS before the intervention of an effective vaccine or treatment.

Unprotected sexual intercourse and use of contaminated needles are intentional activities. Voluntary changes in behavior to avoid a high risk of transmission is currently the overriding public policy objective. The first line of defense in controlling AIDS, therefore, is to inform and educate individuals about high-risk behavior and about methods of altering behavior to protect against transmission of the infection.

Despite philosopher George Santayana's famous injunction that those who do not remember the past are condemned to repeat it, history holds no simple truths. Nevertheless, there are a number of significant historical questions relating to the AIDS epidemic. What does the history of medicine and public health have to tell us about contemporary approaches to the very difficult dilemmas raised by AIDS? Is AIDS something totally new, or are there instances in the past that are usefully comparable? Are there some lessons in the way science and society has responded to epidemic disease in the past that could inform our understanding of and response to the current health crisis?

There are obviously no simple answers to such questions. History is not a fable with the moral spelled out at the end. Even if we could agree on a particular construction of past events, it would not necessarily lead to consensus on what is to be done. And yet, history provides us with one means of approaching the present. In this regard, the history of responses to particular diseases can inform and deepen our understanding of the AIDS crisis and the medical, social, and public health interventions available.

The AIDS (acquired immunodeficiency syndrome) crisis has aroused scientists to major research efforts and the public at times to near-hysteria. The media and their audience eagerly await the latest scientific reports, yet the public seems to respond selectively, embracing the most frightening interpretation of the data and discounting attempts to place those data in perspective. One might be tempted to conclude that questions of public health policy are best dealt with by expert judgment unsullied by lay opinion. Yet such an attitude supposes scientists to be governed by pure reason and to be beyond influence by narrow self-interest or by political or moralistic considerations, a self-serving assumption belied by an examination of the record. The erosion of public confidence in science has indeed bedeviled health authorities in their efforts to generate consensus on the policies they wish to implement, but the public response—including the response of scientists to AIDS—is a far more complex phenomenon.

It is nearly six years since the first evidence of the AIDS epidemic was seen, with the report of five cases of Pneumocystis carinii pneumonia diagnosed in young, otherwise healthy homosexual men in Los Angeles. The report was surprising, for although P. carinii is a common human commensal, the pneumonia essentially occurs only in the presence of severe immune suppression. Similar reports quickly followed from New York City and San Francisco, with the additional observation that Kaposi's sarcoma—a malignancy usually seen only in elderly men in this country—was also occurring epidemically among young homosexual men.

Since then, the epidemic has evolved at a relentless pace to a reported 32,000 cases in the United States by March 1987. The epidemic has sparked a massive multidisciplinary scientific effort, resulting in the successful identification of the causal agent—the human immunodeficiency virus (HIV)—within two years from the first report and producing a commercially available antibody test within four years.

In 1984, scientists isolated a new pathogen, now called human immunodeficiency virus (HIV), that is almost certainly the etiological agent for the acquired immunodeficiency syndrome (AIDS). It has been estimated that there are between 500,000 and 1,750,000 asymptomatic, chronically HIV-infected individuals in the United States. In a remarkably short time, investigators developed a number of blood tests that indicate whether an individual is likely to be infected with this virus. These assays are now being used to test patients with symptoms suggesting AIDS or related syndromes, to screen donated blood, to evaluate individuals concerned about their infection status, and to screen new military recruits, active-duty soldiers, and ROTC students. Almost weekly, new proposals are advanced for screening different subsets of the population.

This paper presents the available epidemiological data on human immunodeficiency virus (HIV) infection and AIDS among intravenous (IV) drug abusers, reviews HIV disease among intravenous drug abusers, and focuses on initial research findings that indicate intravenous drug abusers not only are educable but may indeed be altering their lifestyles as a direct consequence of their fear of HIV infection.

Although the initial clinical cases of AIDS were described in 1981, among gay men living in Los Angels, only a short time elapsed before IV drug abusers who shared their drug paraphernalia were identified as another risk group. A reasonable hypothesis, based on reports from the New York metropolitan area, is that there has been a relative increase in the percent of AIDS cases among IV drug abusers as compared to homosexuals. This may be explained by the transition group of sexually active homosexual men who also used intravenous drugs and thereby spread HIV from the gay community to IV drug abusers. In support of this hypothesis, the Centers for Disease Control (CDC) estimates that 8 percent of all reported AIDS cases from New York City have both risk factors.

Research on AIDS involving human subjects poses in stark form a familiar dilemma: Can the demands of a rigorous scientific research design be met without violating the rights or harming the interests of research subjects? The dilemma is especially troubling in the early phases of drug research, when promising medications showing some signs of success in combatting this fatal disease must be tested for safety and efficacy. The research design using randomized controlled trials, in which an experimental drug is tested against a placebo, highlights the dilemma. Although the use of this research design does not pose the only ethical problem for AIDS research, it is perhaps the most dramatic. Related ethical issues include the question of when an experimental drug that holds out the only present hope may be released for general use; who should be selected to receive experimental drugs that are in short supply; how much information should be released about safety and efficacy while a clinical trial is still in progress; and what factors determine the appropriateness of early termination of a study.

Researchers trying to resolve the questions surrounding the AIDS epidemic may feel like Hercules trying to slay the Hydra: for every head that is cut off, two new ones grow in its place. Doctors have never treated their patients in a social vacuum, but the expectations and anxieties engendered by AIDS are bringing fundamental changes in clinical p-actice. Drugs are being raced from the laboratory bench to the bedside, health care providers are being forced to recognize new types of family constellations, and the general public is being shocked into awareness of the importance of prudent infection control policies. Clinical practitioners have had to deal with the ethical consequences of routine and arcane decisions as never before, knowing that yesterday's experiment or hospital rounds can become tomorrow's lead feature in the news media.

The acquired immunodeficiency syndrome (AIDS) and the entire spectrum of disease associated with infection by the human immunodeficiency virus (HIV) are the subject of intense international interest and concern. From the viewpoint of the World Health Organization (WHO), HIV is not simply one of a series of newly recognized diseases emerging during the past decade but is a problem with several biological and epidemiological features that justify a unique sense of urgency among public health officials, political leaders, and the general public.

This article describes the evolution of a global perspective and response to HIV, reviews the current international epidemiological situation, explores the principal elements, both conceptual and operational, of WHO's global strategy for HIV control, and discusses the major approaches to HIV prevention in the current global context.