If you have been following the search for the origin of the pandemic coronavirus strain in the news you will know the various theories. Pangolins, bats and a variety of other wild animals have been considered as possible carriers. The finger of blame has also pointed to a virology laboratory outside of the Chinese city of Wuhan which some have accused (without evidence) of manufacturing the virus and releasing it on the world.
This search for origins is partly an effort to assist containment and treatment and partly a variation on the search for meaning in what is a situation outside of human control. The search for the virus’s first leap to a human victim is mirrored in the efforts at contact tracing and finding the “patient zero” of each individual outbreak.
Most epidemiologists would tell you that this is a futile quest. Chances are that the virus moved from animals to humans multiple times before it became a strain that could spread from human to human. And likewise, given what we know about asymptomatic carriers of viruses, it would be difficult to pin point a single person responsible for the introduction of the virus into a city or country or nightclub.
Yet the search for “patient zero” has a huge appeal. At the moment, when we fear the virus and have no vaccination or cure, there is a potential danger in this interest in finding the single source of any outbreak.
The danger is that, like in the past, a person carrying the disease will become a scapegoat for all our fears. There are plenty of examples from history. Mary Mallon, an asymptomatic carrier of typhoid fever, became "Typhoid Mary" and lived out her days on a deserted island to prevent her from transmitting the disease to others.
Was she the only asymptomatic carrier of typhoid fever in early 20th century New York? Certainly not. As Judith Leavitt has described, Mallon became an example to New Yorkers of public health policy in action. Since she refused to change her ways, or really to give up the only job she had been trained for, she was imprisoned to keep the public safe.
The term "patient zero" was famously used during the Aids epidemic of the 1980s to describe the gay Canadian flight attendant Gaetan Dugas. Dugas was not the first person in North America to get the virus but he rapidly became a kind of demonised figure, even within some portions of the gay community, for his supposedly reckless behaviour once diagnosed with the disease.
When researchers began contact tracing among the patients they were seeing they soon found he had had sex with several of them. Did Dugas spread HIV to many others? Yes. Was he the only one? Certainly not.
In the case of both Mallon and Dugas, the science around transmission of each disease was still emerging. Neither appear to have fully understood the threat they might pose to others yet each was reviled for their endangerment of healthy people. Each of them was singled out against a backdrop of thousands of people infected with HIV or typhoid fever and each of them suffered for that.
As we transition into greater contact with one another, we should remember these examples. Indeed, the control measures that countries are implementing now encourage a search for the origins of outbreaks. We need to remember that we still don’t fully understand all the ways that this strain of coronavirus can be transmitted and there are a wide variety of symptoms.
We need to do the best we can to keep each other safe and for now that means a lot of testing and contact tracing. But no one will be safer if we tie that to a search for an individual to blame for each outbreak or if we reduce anyone’s humanity by labelling them a “patient zero”.
Dr Juliana Adelman lectures in history at Dublin City University