If there’s one thing that we’ve learned about the coronavirus since March, it’s this: the virus spreads quickly and all too easily.
Just consider this startling fact presented by Maria Van Kerkhove, technical lead for the World Health Organization’s Health Emergencies Program. “There are some really good estimates out there that suggest that between 10% and 20% of cases are responsible for about 80% of transmission events.”
Why does COVID-19 spread so easily, and what can we do about it?
Why Is COVID-19 a “Superspreader”?
Though the coronavirus is hardly the only respiratory disease to spread in clusters, it acts more aggressively than other such infections. This occurs due to a perfect storm between human behavior and the way that COVID-19 spreads.
Namely, COVID’s ability to transmit through the air and in closed indoor settings. People of all ages can spread the coronavirus days before they even know they’re sick. Or, even worse, many people who are infected remain asymptomatic and accidentally spread the infection without ever thinking they need to be tested.
In fact, research suggests that 40% of coronavirus transmission takes place before a patient shows symptoms. As explained by Smita Gopinath, an immunologist at the Harvard School of Public Health, “Viral load increases a couple of days before symptoms show up.” This explains why bars, restaurants, clubs, places of worship, and factories have become high-risk areas.
Examples of Rapid Transmission
Hong Kong’s Lan Kwai Fong nightlife district provided an early example of the coronavirus “superspreading” at public events. According to The University of Hong Kong, the virus spread among 106 bar patrons, musicians, and employees over a period of two weeks in March. But only a few infected individuals are suspected to be responsible for the initial transmission.
Today we understand the risk of COVID-19 transmission in bars, but in March we were still learning the behavior of the pandemic. As Dr. Gabriel Leung, dean of medicine at The University of Hong Kong, explained, “Any setting that is an enclosed space that is poorly ventilated, that is crowded and that has unprotected behavior would tend to create a lot of clusters.”
What Does All of This Mean?
It’s one thing to understand the “superspreading” nature of COVID-19. But how do we use that knowledge to prevent spikes in the pandemic?
Scientists are still working to determine the implications of new research on our collective COVID-19 response. They want to identify which details of person, place, and time are most significant. It’s clear that COVID-19 carries the natural tendency to spread rapidly, which means that containing the coronavirus will require intensive interventions that past outbreaks never required.