You know things are serious when SEC sports are put on hold and church services are canceled. Nothing could be more true right now as we begin to face the reality of dealing with the CoViD-19 global pandemic.
There is an incredible amount of information out there regarding the coronavirus. It is difficult to know what all of it means, especially when new data are constantly coming in.
Because this is a novel coronavirus, individuals have no immunity to the virus. There are no vaccines against the virus. While there are several antivirals being used in trials, there are no approved pharmaceutical answers to treating infected individuals. This is why non-pharmaceutical interventions are incredibly important.
One non-pharmaceutical intervention is social distancing (i.e. the reason March Madness was canceled). A phrase that has been used in the media in conjunction with social distancing is “flattening the epidemic curve.” This idea is rooted in fundamental epidemiologic principles and historical precedent.
Common methods used to assess the scale of an infectious disease outbreak in epidemiology are calculating the reproductive number and plotting epidemic curves.
The reproductive number is the average number of people in an entirely susceptible population who will get sick after being in contact with an infected individual. When the reproductive number is greater than one, there is epidemic. Therefore, the intent of interventions is to drive the reproductive number to below one.
The reproductive number can change a lot throughout the course of a pandemic. Right now, estimates show that each case, on average, infects two to three other people. The number of contacts a sick person has contributes to this number, so limiting contact between people is a way to help lower the reproductive number.
Epidemic curves are essentially plots used to help visualize the number of cases over time. The objective of social distancing is to have fewer people get sick at a given time. In essence, we want to make a molehill out of the proverbial mountain. In Italy, the epidemic curve has climbed very quickly toward its peak. The high number of cases in such a condensed time frame has overwhelmed the healthcare system. By vigilantly distancing ourselves and limiting unnecessary contact, we are actively helping to flatten the epidemic curve.
Historical precedent shows that social distancing can work. During the 1918 Influenza pandemic, the city of Philadelphia did not practice social distancing and instead continued to hold mass gathering events like parades. On the other hand, St. Louis implemented strict protocols for social distancing. The case fatality rate, or the fraction of people who died after getting sick, was much higher in Philadelphia since their healthcare system could not keep up with the number of cases.
Another important thing to note with social distancing is that it extends beyond staying home when you are sick. With CoViD-19, roughly 80 percent of people will have mild infections, and a number of those individuals will not show symptoms. Children are a prime example of asymptomatic cases. Even without symptoms, infected individuals can pass the virus to others. Therefore, everyone must practice social distancing for it to work.
As a former college athlete, avid sports fan, and churchgoer, I commiserate with the disappointment of such a stark upheaval to our everyday lives. As an epidemiologist, however, I cannot stress enough how important it is to embrace this temporary reality. We are at a moment in history. We can help shape a narrative of selflessness and compassion as well as help shape the epidemic curve.
Sarah Elizabeth Scales is a Millsaps Alumna and Madison native. She is a Master of Public Health candidate at Columbia University’s Mailman School of Public Health and will begin doctoral work at the University of Delaware in the fall.
