If you don't like what the experts are saying about AIDS and HIV, about causes and effects, just wait a minute and you'll hear something else.
AIDS confounds us. In the wake of the summer's political conventions and the Amsterdam, Holland, AIDS conference, convenient ways of thinking about the disease are again cast into doubt. Does HIV, the human immunodeficiency virus, "cause" acquired immune deficiency syndrome? What about the dozen or so recently described cases of the syndrome without evidence of HIV infection? Does anal sex "cause" AIDS? What about the dramatic upsurge in cases among women and, more generally, among AIDS patients' heterosexual partners?
Patients with AIDS -- with almost any illness -- understandably want answers to twin questions: "What's causing this thing?" and "How is it going to play out?" In the current AIDS epidemic, these questions of causation and prognosis have become vexed ones. Especially in the matter of cause, there is bitter debate.
That's what I see as a physician.
As a historian of medicine, I look at the welter of controversies surrounding the HIV epidemic, and it seems thoroughly familiar. All sides appear to suffer from a case of acute history deprivation.
What is the "cause" of AIDS? The quest for an answer has been the occasion for much ink shed, with at least three camps more or less established:
* The narrow or "condensed" view, probably representing the majority of scientists, attributes AIDS to one or more retroviruses and explains seeming anomalies in disease patterns by citing the unusual immunologic injury brought about by those viruses.
* A middle-ground position accepts HIV as the primary cause of AIDS but postulates a variety of chemical, microbiological or even environmental "co-factors" that greatly affect the course of the disease.
* A behavioral or "expanded" view, espoused by a small number of investigators who suggest that HIV, or in fact any virus, has little or nothing to do with AIDS: that it is more likely "caused" by damaging behaviors, especially drug-taking, thus discounting the likelihood of its spread to clean-living heterosexuals.
None of this is surprising. In the manner of ritual incantation, if we can just come up with the right explanatory framework, if we can just properly "know" what causes the disease, then maybe we can make ourselves proof against its onslaught. Our basis for understanding AIDS and its root causes also has enormous social, political and economic ramifications.
Every epidemic (even in our own time: Remember legionnaires' disease? Toxic shock syndrome?) has become the focal point around which factions have squared off, each propounding a pet theory of causation. Find the causal "agent," and you've found, more often than not, the likely remedy. And therein lies the rub. Unconsciously, we reason backward.
He who favors one remedy will preferentially seek the "cause" that prompts it. If I believe that behavior change is the answer to HIV, I will gravitate to explanations that emphasize the role of behavior (say, drug-taking) as the primary "cause" of AIDS.
When we seek to understand what happens inside our own bodies, we scorn complexity and ambiguity. Consider: Is AIDS an acute illness or a chronic disease? The awkward answer, as was the case with the advent of syphilis in the early modern era, is of course both. Is it caused by bad germs or by bad character? Again, long after the germ theory of disease was in common parlance, there was still debate about some sexually transmitted diseases being punishment for "bad" behavior.
There was another variation on this theme in the last century. Acute illnesses such as cholera, as well as chronic ones such as tuberculosis, became politically charged crises around which raged fractious debate. Factions favoring the germ theory vied with sanitarians who at the time seemed more progressive as they pushed environmental cleanup. Later, at the turn of the century, it was still possible for experts to argue savagely about yellow fever. Was it caused by a bacterial organism? (Viruses were not yet known.) By mosquitoes? By swampy conditions? Their conclusions were consequential, with enormous repercussions on Western nations' economic welfare, the capability of armies and the expansion of empire. Others rushed to blame beriberi and pellagra on germs, ignoring the notion that something might be lacking in patients' diets.
In the roiled waters of today's AIDS crisis, we founder on the shoals of causal theory. Part of the problem is a persistent and simplistic notion of what it means to establish a proper causal connection between a bug and a disease. Many people engaging in fringe research on AIDS note, as did some syphilis investigators for much of this century, that HIV cannot be demonstrated to satisfy the famous postulates of Robert Koch. Koch, the German pioneer of microbiology, derived a series of criteria that should be met in the laboratory to establish the causal relation between an organism, such as the anthrax bacillus, and a disease supposedly associated with it. What today's controversy fails to deal with is the frequency with which Koch's postulates were honored in the breach -- how often his procedures have had to be modified to take into account more recent discoveries of rickettsial and viral diseases. Perhaps most important, clinical medicine and epidemiology have come far in both reinforcing and extending Koch's original program.
Today's combatants, including much of the scientific community, are engaged in what can be called "splitting." If it's the virus, what is the role of risk-prone behaviors? If it's a punishment from on high -- "nature's revenge" -- what of the underlying biological reality, and the children with transfusion-induced -- or, as in Romania and Africa, tragically, injection-transmitted AIDS? Arguing that heterosexuality makes us proof against this disease is bracing and feel-good, as was muscular Christianity a century ago. But does it help us forestall a catastrophe the likes of which we see in Africa today?
Studying the history of epidemic disease cannot direct us to a cure as we try to get ahead of HIV's brutal curve. It can, however, divert us from the easy pitfalls of wishful thinking; of simplistic choices between the multiple, interacting biological and social factors that produce the full-blown illness; the glib, preachy moralism that loses lives to save souls; and finally, the distracting arguments about whether HIV is really the culprit. Of course it's the culprit. Or, rather, a culprit. As are risky behaviors, the organisms that produce opportunistic infections, ignorance, poor host resistance and poverty. As they say about spaghetti sauce, it's all in there.
A booster shot of historical common sense seems in order. It is almost as though in Walter Reed's time at the turn of the century, physicians and reformers had stood still in the fight against yellow fever until "the" cause of the disease had been defined with unassailable proof. Had that been the case, many more would have died before Reed cut the Gordian knot with drainage ditches, some mosquito nets and a lot of common sense.
Ultimately, then, what the historical record pleads for is more common sense and less hollow theorizing. While victims die, expert-combatants are locked in a Kabuki-like dance of causality. Yet rarely do we end up with the luxury of unicausal explanations; rarely in today's medicine is there a single magic-bullet cure.
We need to get on with the business of tackling AIDS on all fronts at once. Otherwise, more people die.
Russell Maulitz is a medical historian and practicing general internist in Philadelphia.