Lesson 3: AIDS and Infectious Disease Epidemiology


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  1. Lesson 1: Explaining Disease Origins and Causation

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    The first lesson provides an opportunity to compare attempts to understand and explain past outbreaks of disease in Western Europe with early American responses to AIDS.Close

  2. Lesson 2: U.S. Groups, Individuals, and Behaviors

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    The second lesson examines how particular groups, individuals, and behaviors have been targeted in past responses to plague, syphilis, cholera, polio, tuberculosis, and typhoid fever.Close

  3. Lesson 3: AIDS and Infectious Disease Epidemiology

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    The third lesson explores the early work of American epidemiologists who investigated the newly recognized syndrome. The lesson pays particular attention to the Los Angeles cluster study which, in its attempt to provide evidence to support the idea that AIDS was caused by a sexually transmissible agent, introduced the term “patient 0.”Close

  4. Lesson 4: And the Band Played On: Randy Shilts’s History of the American AIDS Epidemic

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    This lesson focuses on the writing, promotion, and responses to the best-selling history of the American epidemic written by a gay San Francisco journalist, a good deal of which focused on his identification, characterization, and rechristening of the individual at the center of the CDC’s cluster study as “Patient Zero.”Close

  5. Lesson 5: Responses to “Patient Zero”

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    The fifth lesson investigates the widely diverging responses to Shilts’s characterization of Gaétan Dugas as “Patient Zero.”Close

  6. Lesson 6: New Patient Zeroes

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    The last lesson evaluates the idea’s legacy for the investigation of subsequent epidemics and its potential to obscure important determinants of health and sickness.Close

  7. About the Author


In 1981, the recognition in the United States of a seemingly new and often fatal disorder—noticed first amongst gay men and later seen amongst injection drug users, blood product recipients, and some Haitian immigrants—led to the involvement of epidemiological investigators from the U.S. Centers for Disease Control (CDC). In a series of studies, the CDC attempted to unravel the complex medical, social, and environmental factors that might have placed these individuals at increased risk for the condition, which by mid-1982 had become known by the acronym AIDS. One investigation, the 1982 Los Angeles cluster study, attempted to trace sexual connections among a number of gay men residing in California who were amongst the earliest reported cases of AIDS in that state. A non-Californian man with Kaposi’s sarcoma (KS)—a type of skin cancer often used as a way of diagnosing AIDS before the discovery of a causative retrovirus—was linked as a sexual contact to four of these patients. This individual’s status as the “Out-of-California” patient was originally abbreviated to the letter “O,” which in turn was given additional resonance when researchers read this as the number “0.”

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The initial results of the Los Angeles cluster study were published in the Morbidity and Mortality Weekly Report in June 1982, and made reference to “the non-Californian with KS.” A more detailed analysis which extended the cluster of AIDS cases linked through sexual contact to include 40 men in 10 cities appeared in 1984, by which time this individual received the designation “patient 0” and a central position in a diagram depicting the sexual network. While his central role in cluster study would later come under criticism, as Moss’s 1988 letter makes clear, “patient 0” and the cluster study were viewed by many in 1982 as important evidence for the possibility that an unknown sexually transmissible agent caused AIDS.

Oppenheimer’s chapter sets the context for the CDC’s AIDS investigations between 1981 and 1990, and highlights the multifactorial disease model that is central to epidemiology and which represents, he argues, the discipline’s strength as well as its weakness. Grover offers a strong critique of the concept of an “AIDS carrier” and the focus of the media on “patient 0,” arguing that the language used in public discussions of AIDS serves as a vehicle for the reproduction of dominant social power relations and prejudices. Close


  • Auerbach, David M., William W. Darrow, Harold W. Jaffe, James W. Curran. “Cluster of Cases of the Acquired Immune Deficiency Syndrome: Patients Linked by Sexual Contact.” American Journal of Medicine 76, no. 3 (March 1984): 487–92.
  • Grover, Jan Zita. “AIDS: Keywords.” October 43 (Winter 1987): 17–30. JSTOR (3397563).
  • Moss, Andrew. “AIDS Without End.” The New York Review of Books, December 8, 1988.
  • Oppenheimer, Gerald M. “Causes, Cases, and Cohorts: The Role of Epidemiology in the Historical Construction of AIDS.” In AIDS: The Making of a Chronic Disease. Elizabeth Fee and Daniel M. Fox, eds. Berkeley, Los Angeles, and Oxford: University of California Press, 1992, pp. 49–83.
  • Task Force on Kaposi’s Sarcoma and Opportunistic Infections, Centers for Disease Control. “A Cluster of Kaposi’s Sarcoma and Pneumocystis Carinii Pneumonia among Homosexual Male Residents of Los Angeles and Orange Counties, California,” Morbidity and Mortality Weekly Report 31 (1982): 305–07.

  1. How did the initial recognition of AIDS amongst certain socially marginalized groups shape the early investigations and responses to the epidemic in the United States? How did researcher interest in and access to sick members of these groups affect what became known about AIDS?
  2. To what extent did the recognition that people with AIDS included certain injection drug users, hemophiliacs, Haitians, and heterosexual women, and not solely gay men, change the public health and wider social responses to AIDS?
  3. What was the perceived significance of the cluster study when it was first published in 1982? In 1984? In 1987 and later? In what ways had knowledge about AIDS changed in the intervening years?
  4. What functions does the cluster diagram (Fig. 1) perform in the 1984 article? What aspects of the collected data discussed in the article are rendered visually? What do these choices emphasize? What do they omit?
  5. Grover explores the ways in which language can convey social assumptions and misconceptions. Does “patient 0” have a precise meaning? How have different groups interpreted and defined the term?