In the lexicon of infectious diseases, the term 'Patient Zero' denotes the primary case of an outbreak, the first person to show symptoms of an illness. The idea that an epidemic can be traced to a single individual, the high-stakes search for such a person, and the mapping of the routes of disease transmission are recurring themes in popular culture. Films such as Contagion (2011), 12 Monkeys (1995) and 28 Days Later (2002) portray the gruesome effects of viral epidemics set off by a lone human, while history's most notorious primary carrier, Typhoid Mary, has become synonymous with a person who spreads disease to others, sometimes deliberately.
Within the history of AIDS in the United States, Patient Zero is the moniker of a Canadian flight attendant named Gaëtan Dugas, who was thought to have picked up HIV in either Haiti or Europe, introduced the virus to North America, and infected hundreds of sexual partners before his death in 1984. However, the creation of the term 'Patient Zero' and the designation of Dugas as the primary case came at the hands not of the medical community but of Randy Shilts, an American journalist. His book And the Band Played On (1987) documented the early years of the AIDS crisis, weaving an account of its emergence in gay communities in New York City and San Francisco with an indictment of the Reagan administration for its indifference to the disease and the suffering it was causing.
In the medical literature, Patient Zero had been referred to as 'Patient O' – that's the letter 'o', not the number '0' – to designate his geographic location outside of California, where the studies originated. But the Shilts book transformed Dugas into 'Patient Zero', a uniquely reprehensible creature who carelessly, even maliciously, continued to have sex with many partners without regard for their health, even after being told by his physicians to stop. Calling him 'the Quebeçois [sic] version of Typhoid Mary', Shilts described a handsome 'blond with a French accent' who 'would have sex with you, turn up the lights in the cubicle, and point out his Kaposi's sarcoma lesions. "I've got gay cancer," he'd say. "I'm going to die and so are you."'
For decades, Dugas has been known as the Patient Zero of the AIDS epidemic. But as the authors of a recent article in Nature found, HIV in fact entered the US several years before Dugas arrived on the scene. By conducting new genetic analysis of stored blood samples, the researchers determined that the virus probably arrived from the Caribbean by 1971, possibly in contaminated blood products such as plasma. Thus Dugas, the man who had been blamed for singlehandedly igniting the AIDS crisis in the US, was not the source of the epidemic but simply another victim of a disease that has, to date, killed more than 35 million people worldwide.
If the story of Dugas as Patient Zero was scientifically inaccurate, the mere invention of a journalist in search of a literary prop, then why did it persist for so long? What makes the idea of a primary case so compelling, and what does our fascination with it reveal about our need for narratives to make sense of what seems beyond our grasp?
Even before Dugas, the idea of Patient Zero suffused tales of outbreaks. In 1900, public health officials discovered the dead body of a 41-year-old Chinese man named Wing Chung Ging in the basement of the Globe Hotel in San Francisco. Suspecting bubonic plague, they ordered an immediate quarantine of Chinatown. Within a day, every white person had been directed to evacuate from the neighbourhood, and health authorities ordered a house-by-house fumigation and the vaccination of all Chinatown residents. In early 20th-century New York, Mary Mallon, the Irish immigrant dubbed 'Typhoid Mary', was forcibly quarantined after public health officials determined that she was spreading disease to unsuspecting families while working for them as a cook. In each case, the state harnessed scientific authority to enact coercive measures, drawing on contemporary beliefs that a person's race and class could shape their propensity for, and response to, disease.
The allure of Patient Zero rests on the ways in which the figure allows us to assign responsibility and blame when an outbreak occurs. It makes visible the vectors of disease transmission and draws attention to the dangers of human contact, creating distance between the afflicted and the rest of us. When Patient Zero is defined as someone with distinguishing traits of behaviour, sexuality or race, then those of us with differing characteristics can reassure ourselves that we are not at risk. A Patient Zero lacks both the capacity for self-control and the moral conviction to avoid placing others in danger. The more he or she strays from established norms, the greater the opportunity for reprobation. As the scholar Priscilla Wald writes in Contagious (2008), this stigmatisation 'is a form of isolating and containing a problem' as well as 'a means of restoring agency – which, as in the [rumours] of willful infectors, melts into intentionality'. Dugas reportedly had 250 sexual partners per year – and his 'deviant' sexual practices and awareness of his HIV-positive status augmented both his liability and immorality.
The resonance of the figure of Patient Zero, whether in a bygone outbreak or an emerging epidemic, underscores our collective desire to fit new information into old frameworks. Outbreak narratives are comforting in their familiarity; they tap into our need to bring order to that which appears disordered. The outbreak narrative classifies the practices of an individual or group as unnatural, aberrant, and likely to foster disease. Recall, for example, the rhetoric in 2004 around H5N1, a deadly strain of avian influenza that arose in parts of Asia where people had close contact with diseased birds, both live and dead. Or consider the 2014 Ebola outbreak, with its origins in a West African village where deforestation brought infected wild animals into close proximity to humans. These outbreaks, as well as the ones depicted in the films Outbreak (1995) and Contagion, locate disease origins in 'primitive', 'pre-modern' parts of the world – usually African or Asian, always non-Western. The collision of traditional ways of life with the trappings of modernity, particularly the international movement of capital and the air travel that undergirds it, threatens global health by highlighting the uneasy juxtaposition of old and new.
The focus on Patient Zero in an emerging outbreak is not merely a way to discharge culpability. It also frames social and political responses to an epidemic, with very real consequences for public health. Dugas's embodiment of HIV shifted analysis to the realm of individual behaviour while deflecting attention from structural factors that affected transmission and health outcomes, such as poverty and access to healthcare. In the 1980s, the epidemiological focus on gay men obscured the increasing numbers of women with HIV. And when the Centers for Disease Control and Prevention identified those at high-risk for AIDS – homosexuals, haemophiliacs, Haitians and heroin users, popularly tagged the 4-H club – there was little concurrent discussion of the variables that made Haitians in particular such disproportionate casualties of the epidemic. More recent outbreaks with origins in the Global South, including severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), underscore the health disparities that govern the worldwide distribution and outcome of infectious diseases. A programme that aims to minimise future outbreaks must address global poverty and wealth inequality, and not simply come up with new ways to protect industrialised societies from Third World threats.
The announcement that Dugas did not bring HIV to North America is not likely to change how we think about AIDS today, more than 30 years into the epidemic. But it provides an opportunity to challenge our fixation on the idea of Patient Zero and how it influences our responses to disease. The outbreak narrative is a device with the power to impact politics and therefore the health of populations. The exoneration of Dugas should serve as a warning of the risks of overinvesting in the myth of Patient Zero. Each disease emerges from the structural conditions surrounding it. Casting blame on a Patient Zero merely distracts us from the larger and more important task of tackling the inequalities that shape global health.
Leyla Mei is a writer and medical historian in New York City. She has a PhD in American history and writes on topics of disease, risk and race.
This piece was originally published in Aeon magazine.