An Unknown Transmissible Agent
On March 4, 1983, after a year of suggestive data, a Public Health Service interagency report (published in the MMWR ) marked a major shift in the conceptualization of the disorder.[59] What caused that shift was in part the kind of evidence cited by JAMA : Case reports to and surveillance by the CDC made it clear that the disease was more than a syndrome of homosexual men and promiscuity.
On July 9, 1982, the CDC had reported that thirty-two Haitian immigrants to the United States, seven of them women, showed immu-
nological, morbidity, and mortality patterns similar to those in homosexual men and intravenous drug users.[60] Although the MMWR had previously published two general updates on the increased incidence of the new disease—updates that had included data on heterosexual patients—the article on Haitians constituted the first complete report focusing directly on persons outside the "homosexual" category.
A week later, and again in December 1982, the MMWR alerted its readers that patients with hemophilia but no other underlying disease had contracted PCP.[61] The CDC observed that inquiries concerning the patients' sexual activities, drug usage, travel, or residence offered no evidence that the cases were in contact with each other, with homosexuals, intravenous drug users, or Haitian immigrants. What the hemophilia patients shared was a dependence on Factor VIII, the clotting substance they lacked, usually derived from the pooled blood of two thousand to twenty thousand donors.[62]
The possibility of blood as a vector for AIDS was heightened by a CDC report of unexplained immunodeficiency and opportunistic infection in a twenty-month-old infant who had received multiple transfusions, including platelets from a donor subsequently diagnosed with AIDS.[63] The sibling of the infant was in good health and his parents were described as "heterosexual non-Haitians" without a history of intravenous drug use.
Summing up the new cases, the March 4 MMWR observed that current epidemiological data indicated four groups were at increased risk of contracting AIDS: homosexual men with multiple sexual partners, users of intravenous drugs, Haitians who had emigrated to the United States in the previous few years, and hemophiliacs. In addition, unexplained immunodeficiency and life-threatening opportunistic infections had occurred in the female sexual partners of bisexual or intravenous drug-using men, and the children born of their unions.
Instead of life-style, the report hypothesized that the cases shared exposure to a transmissible agent. Though the agent was unknown, the pattern of cases mimicked that of a known pathogen, one that epidemiology had studied and helped control in the years before AIDS:[64]
The distribution of AIDS cases parallels that of hepatitis B virus infection, which is transmitted sexually and parenterally. Blood products or blood appear responsible for AIDS among hemophilia patients who require clotting factor replacement. The likelihood of blood transmission is supported by the occurrence of AIDS among IV drug users. Many drug abusers share contaminated needles, exposing themselves to blood-borne agents, such as hepatitis
B virus. Recently an infant developed severe immune deficiency and an opportunistic infection several months after receiving a transfusion of platelets derived from the blood of a man subsequently found to have AIDS.[65]
In adopting the hepatitis B analogy, epidemiologists posited an alternative organization of known variables, one which stressed a biological agent whose vector was blood and/or its constituents. Although "life-style" factors could be incorporated, they had lost some of their cachet. In the CDC national case-control study, for example, Harold W. Jaffe and his colleagues, reporting their results in August 1983, suggested that life-style factors are indirect causes of AIDS, with a microbe, probably a virus, as the direct cause.[66]
Although epidemiologists had not yet identified an agent, the model of hepatitis B supported the introduction of public health measures. Stated somewhat differently, the model offered a putative point of intervention in the multifactorial "web of causes," even in the absence of a known pathogen. Recommendations previously developed for hepatitis B were applied, with the Public Health Service recommending no sexual contact with persons suspected or known to have AIDS. In addition, members of groups at risk were asked not to donate blood or plasma, and doctors were encouraged to recommend autologous transfusions to their patients. Finally, the Public Health Service called for the development of blood-screening procedures.
On March 4, 1983, for the first time in the MMWR , the CDC referred to "high-risk groups," attesting to the spread of AIDS into multiple segments of the U.S. population and to the relationship between the concept of "high-risk group" and hepatitis B. High-risk groups were those whose members were at greater risk of infection and of infecting others, carrying a microbe that was capable of spreading through sexual and blood-borne traffic. The MMWR underscored that "each group contains many persons who probably have little risk of acquiring AIDS."[67] Nonetheless, no calibration of degree-of-risk was introduced, so no distinction could be drawn. As no microbe had been isolated, risk designation was, in effect, synonymous with carrier status, even among scientists, not to speak of the news media and among the general public.
Some months later the CDC justified its use of risk groups, arguing that classification of individuals was intrinsic to any epidemiological investigation.[68] Classification should not be taken to mean, however, that groups at higher risk for AIDS could transmit the disease through non-intimate contact, because casual transmission was a view unsupported
by available evidence. To use the likelihood of casual transmission as a basis for social and economic discrimination was unfair.
The apology of the CDC missed the point. Grouping individuals may be traditional in epidemiology, both as a means of intervention and as an analytic prerequisite. The political or social consequences of such grouping are rarely examined. In this instance, even if the fear of casual transmission could be eradicated, the groups identified would still be seen as bearing a strong negative relationship to the life-sustaining blood supply. They were created, qua groups, to signify their potential status as carriers of tainted blood and as contaminators. Moreover, the analogy with the highly contagious hepatitis B virus reinforced the association of casual or vertical transmission, particularly for health-care providers, because hepatitis B is transmitted through close personal contact, through all secretions, through wounds and lacerations.[69]
A further consequence of creating "high-risk groups" was to reinforce the relationship between the disease and "marginal" members of the population. This tendency to attribute blame for disease to socially marginal groups is discussed in greater detail in the chapters by Guenter B. Risse, Elizabeth Fee, and Paula A. Treichler. In the case of HIV, although each of the groups ostensibly threatened the remainder of the community through the medium of blood or sex, public health recommendations were intended to inhibit such contamination. Consequently, the disorder could be contained at the boundaries, among people who were "different" from the majority but undifferentiated within each of the "high-risk groups."[70]
One of the dangers of a scientific classification of people based on stereotypes was that it defined the questions raised and thus answered. Such categorization created a Procrustean mind-set evident from the beginning of the epidemic. In early 1982 researchers, in an act of political and scientific oversimplification, designated the new disorder with the acronym GRID (gay-related immunodeficiency), even though the CDC and the New England Journal of Medicine had published reports of heterosexual intravenous-drug-using patients with the new syndrome. At a major conference Michael Gottlieb and his colleagues could report, in a paper entitled "Gay-Related Immunodeficiency (GRID) Syndrome: Clinical and Autopsy Observations," that of the ten adult males in the study with the syndrome, two were exclusively heterosexual.[71]
In 1983, when researchers seriously began to consider the diagnosis of AIDS in patients outside the previously defined high-risk groups, they attempted to fit them into the current categories. How, for example,
should children with immune-deficiency syndrome be categorized? One approach was to link them to established classifications through their mothers, who were characterized as either drug-addicted or, like gay men, promiscuous.[72] Although the researchers did not define promiscuity, it was assumed to exist and to be directly or indirectly explanatory. One subject, "the mother who denied sexual promiscuity or drug addiction," therefore left a lacuna in the case report.[73]
A second article, appearing in the same issue of the Journal of the American Medical Association (JAMA ), offered an alternative explanation of the same phenomenon. Noting that "until recently, AIDS seemed to be limited to adults, predominantly in those with aberrant life styles or exposure to blood products," the authors observed that the children each experienced "household exposure" to one or more individuals in the high-risk groups, including homosexuals, Haitians, and intravenous drug users.[74] As no evidence existed that the children had either been drugged or sexually abused, the investigators proposed the possibility that the patients had been infected through routine close contact. When Anthony Fauci of the National Institute of Allergy and Infectious Diseases repeated the hypothesis in an editorial in JAMA , he raised a firestorm of public fear and confusion.[75]
Ultimately, the hepatitis B metaphor assumed the existence of a highly contagious, infectious agent, probably a virus. Though some favored a new variant of the cytomegalovirus, others, including James W. Curran of the CDC task force, supported the notion of a new infectious agent.[76] In the long run, either hypothesis rested on detecting a pathogen that had hitherto proved elusive.