Hospitals and doctors in the St. Louis area have been preparing for several weeks for a case of the new coronavirus disease to arrive in Missouri.

That happened Saturday, when state and local officials announced that a St. Louis County woman is presumed to have COVID-19. She’s one of about 500 people known to have it in the U.S. The disease, which emerged in China late last year, has killed 3,800 people globally.

Doctors say expanded nationwide testing for COVID-19 could reveal how widespread the disease is. Infectious disease specialist Hilary Babcock spoke with St. Louis Public Radio’s Eli Chen about the new coronavirus and what the first case means for Missouri.

Eli Chen: How worried are you now that there’s been a case confirmed in St. Louis?

Hilary Babcock: This doesn't actually change our level of worry and concern that much. I think we all expected that there would be cases coming to the St. Louis area and expected that they would come probably with a traveler to start with, which is exactly the pattern that we've seen here.

Chen: How fast does this virus spread?

Babcock: That's a hard question to answer. This virus obviously can spread efficiently person to person. It looks like [based on] early data from China that it could spread from one person to potentially two or three, maybe four more people. Most of that data comes from before we put in place these recommendations that we've all been making about social distancing, washing your hands a lot, not shaking hands and avoiding crowded public places. All of those measures decrease the number of people that any one infected person is likely to infect and make it much harder for the virus to spread.

Chen: Who is at the most risk of becoming affected by the new coronavirus?

Babcock: Honestly, everyone is at risk of becoming infected with the virus. None of us are immune to this virus. There's no vaccine to this virus, but the impact of getting infected with this virus is going to be very different across the population. It does look like children can get this virus but rarely become ill and don't appear to have much severe illness associated with it. So that's one bright spot. People who are older — and older in this setting may mean as young as over 60 — do appear to have more severe disease. People that have underlying health conditions already are also at increased risk of having severe disease and complications, meaning to be hospitalized and needing more acute critical care.

Chen: Some people may not show symptoms of COVID-19. Is it still contagious if a person is asymptomatic?

Babcock: It is possible for there to be a small amount of transmission from people who don't have lots of symptoms. But most of the transmission occurs when people are coughing and sneezing. And so if you're not coughing and sneezing, you might shed a little bit of virus into the environment. But it's not going to be at anywhere near the level of people who are coughing and sneezing.

Washington University School of Medicine

Chen: Do you think states can get a good handle on how widespread the disease is if they're only testing a limited amount of people?

Babcock: The short answer is no. I think that testing limitations have been a real barrier to understanding what the spread of this disease in our country is and remain a barrier. So it's great to hear that there are more tests being shipped and being made available. All tests require verification and validation, so it's not like you can receive a test today and start offering millions of tests tomorrow. In the St. Louis area, there is work going on to expand testing capacity. But at this point, most testing is still going through the health department and getting approved by the health department and then testing being done by the state lab. There are some commercial labs that are coming on board with testing capacity, and hopefully that will expand those options.

Chen: In what ways is the new coronavirus more threatening than the flu?

Babcock: The reasons that I think this is a little more concerning is because there is no immunity in our population and no vaccine. And so we expect that this will be able to spread through the community more widely and more rapidly than influenza, given that lack of immunity in the population. And the data that we've seen so far has made it hard to really assess what the mortality rate and the acute illness and severity of illness rates are because testing has been a limitation everywhere. It's hard to know really what denominator we're looking at. So that when we say 2% of people maybe with coronavirus may die from it, that's probably higher than is accurate, since probably not everyone with mild infection was actually identified and so they're not being counted. But it does look like at least so far, the mortality rate is significantly higher than with influenza. And so that is also a concern.

Chen: How can people best protect themselves from the virus?

Babcock: The best way to keep yourself safe from a virus is to avoid large groups, to avoid big public gatherings, to use hand sanitizer if you can find any. If you can't, soap and water works fine and should also be used. Use it a lot. Use it all the time. And then try to avoid touching your face. Try to avoid touching your nose, mouth and eyes. That's another way that you can get virus from surrounding surfaces and get it into your own body to cause an infection.

[Make] sure your kids are washing their hands as much. Change your social habits so that you're not hugging and shaking hands with everyone. But really, I'm trying to push waving. Just wave at people to say hi and goodbye, or maybe a small bow would also be fine. But really try to avoid touching people.

Follow Eli on Twitter: @StoriesByEli

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