In the midst of the COVID-19 pandemic, epidemiology is no longer a niche subject, and I'm sure it's no longer impressive for me to say I've had a long-time interest in it.
However, I do have the undergraduate course record to back up my claim: a bunch of advanced epidemiology classes that I wheedled my way into and crammed into my jam-packed schedule with a combination of petitions and luck.
All of the classes were interesting, but in early March, while watching the first waves of the pandemic start to crash on American shores, I kept remembering a paper about fear epidemics I read in my infectious disease epidemiology class.[^1]
The paper made several important points, two of which are particularly relevant to the COVID-19 pandemic as it stands in May 2020:
- Epidemics of fear of a disease spread faster than the epidemic of a disease itself, because you can be infected with fear by someone who has the disease or by someone who is just afraid of it. That is, the fear-infectious population is a superset of the disease-infectious population, and so you're much more likely to encounter someone who has fear of the disease. Even more importantly, and relevant to this investigation, is that while you have to come into physical contact with someone to catch most diseases from them, you can catch fear of a disease from someone through any kind of social contact (calls, texts, social media, etc.)
- In most classic epidemiologic models, fear of a disease causes you to take rational action that will help you avoid getting it: having sex with a condom to avoid HIV and other STIs, staying home to avoid COVID-19, etc. However, fear can also cause you to take action that may help spread the disease, such as fleeing from a place perceived to be infested with the disease[^2].
In the case of the COVID-19 pandemic, we have multiple kinds of fear to worry about. Some people are channeling their fear into staying home and compulsively washing their hands, which is generally pro-social action that we'd like to encourage. However, other people, infected by fears about the economic impact of the pandemic or other, darker ideas, are out protesting in crowds that seem likely to increase spread of the disease. Still other people are fleeing cities to rural communities, causing a spike in cases in vacation towns.[^3]
[^1] This class was taught by the incomparable Dr. Michael David, a man with two first names and a scholar of MRSA and hospital-related infections who also holds a PhD in russian literature, and featured an all-star cast of guest lecturers. Thanks, Dr. David! [^2] https://www.nytimes.com/2020/03/25/nyregion/coronavirus-leaving-nyc-vacation-homes.html [^3] Need footnotes here