By Cynthia Ayris Kemp
March 16, 2020
The quizzical looks I received when announcing that I was returning to graduate school in 2018 to earn a Master in Public Health stemmed partly from my “almost 60” age. The oft-asked question – “Are you crazy?” – was usually followed by the “What exactly is public health?” question. Months after graduating, the concept of public health is center stage as the COVID-19 pandemic dominates the 24-hour news cycle.
For someone with a penchant for history museums, it should come as no surprise that I was captivated with my coursework in the history of public health, a requirement at Columbia University Mailman School of Public Health. The history of public health is a story woven with plot lines around the discovery, measurement, and prevention of diseases and conditions. Like all good stories, public health has both heroes – think John Snow, the father of epidemiology – and villains, like “Typhoid Mary”.
Mary Mallon, an immigrant from Ireland, worked as a cook for wealthy New York families from 1900 to 1907. A sleuthing typhoid researcher, George Soper, discovered that outbreaks of typhoid followed Mary from job to job. She earned the nickname of “Typhoid Mary” as the first known asymptomatic (healthy) carrier of Salmonella typhi, the bacteria responsible for typhoid fever. She persisted in working as a cook (even after three years of forced isolation), bringing infection and sometimes death to her places of employment.
Following the fast spread of COVID-19 around the globe and through the United States, I have pondered who the “Typhoid Mary” behind today’s coronavirus pandemic might be. Andreas Backhaus, an economist in Belgium who compared cases in South Korea and Italy, might have at least one answer – healthy, young adults under the age of 30. In South Korea where there was widespread testing of its population, 29.9% of all cases fell into the 20 to 29 age group. In contrast, this same age demographic comprised only 3.7% of all cases in Italy which predominantly tested symptomatic individuals who were typically the older population at higher risk of developing severe symptoms.
Backhaus’ comparison alone is insufficient evidence to conclude that young adults are more likely to be the asymptomatic carriers. But I wonder how many young adults are unwittingly the “Typhoid Mary” equivalent of the coronavirus pandemic. The adventuresome among them are taking advantage of cheap airfares to travel while “attending” online classes or working remotely. Others are extending themselves through acts of kindness to grocery shop or walk the dogs for those at higher risk. However, a small study in Germany found that the viral load (a measure of virus concentration) of an asymptomatic person sometimes exceeded that of symptomatic individuals. Thus, decisions to live life as usual could fuel and accelerate the pandemic. The faster COVID-19 spreads, the faster the healthcare system’s capacity is reached.
“Typhoid Mary” is now a colloquial phrase for anyone who, knowingly or not, transmits disease or something harmful or catastrophic. The public health history lesson on Mary Mallon should influence the COVID-19 testing policies of the United States. Ideally, comprehensive testing should be implemented to identify the healthy, asymptomatic carriers – regardless of age – who are vectors of the virus. However, until solutions are found for the dire shortage of testing kits, we must rely on prudent strategies such as social distancing and self-isolation. To a healthy individual, these steps may be perceived as an overreaction, but from a societal perspective, it remains the sagacious action. My individual decisions, joined with each of yours, can change the course of this virus – together, we can save lives. Let’s do it.