Professor and Chair of the Department of Population Health Sciences, School of Public Health
Part of a research team that uses mathematical models to study how the environment affects transmission of SARS-CoV-2, the novel coronavirus, Gerardo Chowell is helping to produce daily forecasts of the virus’ trajectory. His work has been widely covered in the news media during the pandemic.
I SAW THE DANGERS COMING earlier than the average person. We had been doing some of the early epidemiological analysis on COVID-19 and the properties that make this virus so difficult to control.
In early January, I traveled to New York for a conference, and I was the only one wearing a face mask on the plane and on the subway. I wore it everywhere, but people just looked at me strangely. Yet, even then, I was optimistic we could stop the chains of transmission in this country. I figured, “We can do contact tracing. We have the Centers for Disease Control and Prevention, which is the best in the world. We even offered to help China.”
But there were a number of issues, starting with the slow testing rate. We lost a lot of time, and the virus was able to penetrate the population very quietly. There were hundreds of introductions that we didn’t catch. It took the entire month of January for me to realize we weren’t going to cut it, that the virus was becoming widespread across the U.S. I still think about it, and I’m incredulous that we didn’t stop this.
In February, my mother-in-law flew up for a visit from Chile. She’s 70, and as we have learned, the virus is particularly severe among older adults. I was very concerned because my wife and I also have a 10-year-old who had the potential to bring the virus home from school. So about 10 days before DeKalb County schools closed, I pulled my daughter out. I called the school authorities to explain why I was keeping her home, but at the time they were still thinking of the virus as something like the seasonal flu. Thankfully, her teachers were supportive.
For weeks, I found myself having the same frustrating conversation over and over, trying to get people to understand that this was serious. That the fatality rate was an order of magnitude higher than the flu. That the virus was already here. That we already had a problem.
I’d go to the grocery store wearing a face mask, and then see that the cashier who was over 65 didn’t have one. I felt terrible. I kept thinking, “Why aren’t these people being given protection?
Why aren’t they being told how important this is? They’re seeing hundreds of people a day.”
Finally, things started to change really quickly. Nobody saw the pandemic coming, and obviously no one wants to think about horrible things happening. It’s hard to digest. But then you have to adapt — fast. It takes a while for people to get a reality check, but now I hope we’re moving in the right direction.
We are taking lessons from the playbook of other outbreaks. For example, in 2009, a number of countries closed schools for a few weeks during the first wave of the H1N1 outbreak, and that worked to help control transmission. Yet, in the history of pandemics, this is really the first massive, large-scale social-distancing intervention that’s been implemented.
During the Spanish flu of 1918, which had a fatality rate of around 4 percent on average, a number of countries closed schools, prohibited large-scale public gatherings and asked people to wash their hands frequently. But there was not a lockdown or shelter-in-place mechanism. You have to remember, society was much different then. There were no cars, no planes. We did not have the capacity for mass mobility. The population density was much lower, even in cities. This pandemic is unprecedented in terms of scale, severity and the way we were fooled by this virus.
One of the most alarming studies I’ve done is an analysis of the passengers aboard the Diamond Princess cruise ship, which was quarantined in Japan after a coronavirus outbreak occurred onboard. There were early indications from Asia that there could be a high proportion of asymptomatic cases, and here was a population in a confined setting that we could examine over time. The passengers onboard were overwhelmingly older adults, which means they have a higher-than-average susceptibility to the virus. And yet even then, we observed that 20 percent of cases were asymptomatic, meaning the people never went on to develop symptoms although they could still spread the virus. In the general population, the asymptomatic case rate could be as high as 40 percent.
Every virus has a component of asymptomatic cases, but 40 percent is very high. When you combine it with the fact that the virus can spread so easily — through close contacts, aerosols and contaminated surfaces — and the fact that it’s so fatal, it creates a perfect storm.
Still, I think we are going to come out of this pandemic a lot stronger in terms of our attitudes toward infectious diseases. For example, wearing face masks is not something we have traditionally done in this country or in most of the western world. We can also develop stronger systems to detect emerging infectious diseases a lot more rapidly and respond to them in a globally coordinated way. We’re learning the hard way, but we’re still learning and acquiring new behaviors that will help protect us.
Photo by Steven Thackston