COVID-19: An Update?>

COVID-19: An Update

by David Tuller, DrPH  

Editor's Note 3/20/2020: This interview was published on March 13 and a number of recommendations related to COVID-19 (such as on social distancing) have changed since then, as have the number of places around the country that are now closed to in-person business—either voluntarily or by order of state or local governments. We have attempted to note in the text where advice is now outdated. For the most up-to-date information and recommendations, visit the websites of the CDC and World Health Organization.

The situation with the global coronavirus outbreak is developing rapidly, as scientists and doctors learn more about the pathogen and the illness it causes, COVID-19. With a growing amount of community spread in the United States, we asked our editorial board chair John Swartzberg, MD, an infectious disease expert and professor emeritus at the UC Berkeley School of Public Health, for his perspective on the situation—starting with the World Health Organization’s (WHO’s) decision on March 11, 2020, to label the outbreak a pandemic.

The WHO just declared COVID-19 to be a pandemic. What does that mean?

For a pandemic, the major ingredient is that an outbreak of an infectious disease that began in one country has spread to two or more countries, and the disease has begun spreading in those other countries. It’s been clear to everyone I know that thinks about these issues that we’ve been in a pandemic for several weeks. So nothing has really changed with the WHO’s announcement. Declaring this to be a pandemic is to a large extent a legal and bureaucratic change that allows for greater flexibility in how countries can interact with one another in efforts to address the situation.

What do we know and what don’t we know?

We know this new coronavirus causes the disease COVID-19. We know that the predominant way it spreads is by large and medium-size droplets. We also know that the virus is viable on fomites—inanimate objects that people touch, like a counter-top or doorknob. We're not sure for how long; most experts think three days or less depending upon the object's material and humidity. We have good evidence that other viruses, including other coronaviruses, can be transmitted if a person touches a contaminated object with his or her hands and then touches his or her mouth, nose, or eyes. At this time, we are assuming that this route of transmission applies to this novel coronavirus as well. Airborne transmission probably can occur but is not an important means of transmission.

Although COVID-19 presents in ways very similar to influenza, in that it is much more severe in older people and people with underlying diseases, it is 10 or 20 times more contagious. In an otherwise healthy person, the illness seems to run its course in two weeks. It is different from flu in that it largely seems to spare children. We don’t know if they’re being infected and are asymptomatic or if they’re not being infected.

In fact, we just don’t have a lot of good answers to the basic epidemiology of this disease, and the reason why is because we don’t have adequate testing. That’s changing this week—we’ll be getting more testing, and that will continue to increase. What we’re learning now is that someone can have measurable levels of virus a few days before they become symptomatic, so they can likely transmit it to others at that point. When they have a ton of virus and are most infectious is when they’re most symptomatic, but you can still detect some virus for two weeks after they’ve run the course of the illness.

But the lack of information about how and where the disease is spreading has really hamstrung public health professionals in terms of advising the public in how to make the best and wisest decisions. Once we have more information, it will help us answer some basic questions, like what is the real case fatality rate, how is it most effectively transmitted, what measures are the most helpful to prevent further spread, and so on.

So what should the average person do at this point?

Well, we have to define what an average person is. If the average person is an otherwise healthy person under the age of 60, the recommendations are a little bit different than for a healthy person over the age of 60 or 65. And those are people without underlying problems. So there are really three groups of adults we’re talking about—those who are healthy and under 60, those who are healthy but 60 and older, and those who have underlying health conditions, of whatever age.

In terms of the under-60 adults who are otherwise healthy, they should be prudent and practice some degree of social distancing. In my mind, that means trying to talk to people with more space between you. But it also means trying to not put yourself in situations where you’ll be in a crowded place for a prolonged period of time. That would translate into not going to sporting events, concerts, anything where you’d be crammed together with lots of people—if such events haven’t already been cancelled. (Editor's Note: Such events and environments have since been canceled or closed.) Restaurants are somewhere in between. The concern I have about restaurants is not so much that you’ll be in a crowded place, because you can maintain your distance, but that you have a lot of people touching food and cutlery and so on, and you don’t know if they all taking appropriate precautions. But I would not put them in the same category as a basketball stadium.

What about public transportation, including flying domestically?

If you have the choice, and not everyone does, I would not ride public transportation, especially when it’s crowded. If you’re on public transportation when it’s not crowded, you have some degree of control about how close you get to people and what you touch. I also wouldn’t advise anybody to fly now. But sometimes you just have to fly. If you have to fly to see your dying mother, that’s one thing. If you want to fly to have a vacation in Key West, don’t do it.

How about people 60 and over, and those who have underlying health conditions?

The mortality rates start to go up at about 65. Between 70 and 80 it looks like the rates are many times higher, and even more so above 80. So the rate goes up dramatically with age. It appears that being older is an independent risk factor, even if you’re otherwise healthy. For older people and anyone with any underlying health condition at any age, I would do all the things we talked about, but be even more obsessive about all of them. For example, my wife and I are in our early 70s. We’re trying to go shopping once a week, whereas she used to go four times a week. So we’re trying to avoid being out in public as much as we can. (Editor's Note: Dr. Swartzberg is now advising older adults to shelter in place until further notice.)

None of these things are binary, and that’s really important for people to realize. People want to hear, “Do this, don’t do that.” But the reality is that’s not the way life is. It’s not absolute. So we want to do things that can be beneficial to us and try to avoid those things that are not. For example, I’m still going to the gym but I’m meticulous about wiping things down. (Editor's Note: Gyms, including Dr. Swartzberg’s, have since closed.) If I’m on a machine, I try to make sure no one’s next to me. If they are, then I move. I’m much more meticulous about washing my hands and avoiding contact with people.

This opinion does not necessarily reflect the views of the UC Berkeley School of Public Health or of the full Editorial Board at

First published March 13, 2020; last updated March 20, 2020.