Contact Tracing And Testing: Fighting The Spread Of Covid-19

Thursday, May 7th 2020

Contact tracing and testing are two key weapons in the fight against Covid-19. Judy Maggio talks with Dr. Shelley Payne, director of the LaMontagne Center for Infectious Disease and public health expert, Dr. Marilyn Felkner about the critical need for the implementation of these practices as Texas begins to re-open.

Judy Maggio: Talk about why testing is so important and how it goes hand in hand with this contact tracing.

Shelley Payne: So I think testing is really critical with this particular virus because we don't know how many people are or have been infected with it. There clearly are people who have had the virus who have been able to spread the virus that have not, themselves, had symptoms. And unless we know who's infected we don't know who they have spread the virus to or who their contacts are. And so the testing is particularly important with this disease.

JM: And Dr. Felkner, tell us why contact tracing compliments, enhances the testing, how these two work together.

Marilyn Felkner: Well, the first thing that we do in contact tracing, this first step, is to identify the cases. And then those cases can be contacted and instructed in how to isolate. So we've all heard on the news about how to isolate, but I think it's an entirely different thing to find out that you are infected and now you really have to implement those things that you've just heard kind of superficially in the media. So that's one of, that's the first step in contact tracing is identify the case and give them good instructions about isolation.

Then, because Covid is communicable during its asymptomatic, or presymptomatic period, that's where the contact tracing is especially important because you then ask the case, "In the last few days..." I think most people are using two days prior to symptom onset, so that could be almost a week before you're talking to them saying, "Beginning from that day, who all have you had contact with?"

And you should explain to the person what you're defining as contact. So just passing somebody at the grocery store checkout is not really considered a contact. But if you spend 30 minutes, some people are maybe using less, or some specific amount of time with a person in close contact with them, then you give their name and their contact information. And then they can in turn be contacted, warned that they have been exposed, told to quarantine and given somewhere to call so that if they do become symptomatic that followup can be done immediately.

JM: How are we doing with getting more tests out there. I read that someplace like Austin, a city the size of Austin would need like 2000 tests a day to adequately judge the data.

SP: We have not done sufficient testing, thus far, and the criteria for testing have been very stringent. You needed to have symptoms that were really fairly clearly associated with the typical cases of the virus. And in retrospect I think this was not the best approach because many people didn't have the certain classic set of symptoms of respiratory distress, fever, muscle aches, and a number of people were not identified as being infected and were able to spread the disease before it was clear that they did, in fact, have the infection.

We need to be testing a much wider range of people, people who have different symptoms that may be indicative or may not, people who have been in contact with cases that may not have been adequately identified early on, and wide scale testing will identify people and allow us to do contact tracing in order to find out where the spread has occurred. But we're just doing far too few tests to really know the numbers and the extent of infections in Texas.

JM: This is a delicate balance between trying to get people back to work and help the economy and also protecting people's public safety. What gives you pause as scientists in the public health and infectious disease arena about reopening, so to speak?

SP: I think the thing that I'm most concerned about is that people will interpret the reopening as meaning that the danger is passed and they will not continue to observe social distancing and other practices that are important. And I think that we have to find a way to convince people that we can't simply go back to normal right now. We still need to be wearing masks, to be practicing social distancing, and to really be attentive to what's going on.

MF: I think, again, if you are ill, don't go to work. Don't go out in public. Don't wait till the health department calls you and says you have a positive test. Be proactive and responsible. Another thing that I think is important is that there be no stigma. Sometimes we say, "Well, they didn't follow the rules, they didn't wear a mask, or they didn't do this, or that, and they got the disease!" Now, we get the disease, we acknowledge it. We don't want people being afraid to acknowledge they have the disease. We want them to say, "I have the disease and I want you to know that I have the disease so that you can, in turn, protect your friends and family."

*This interview has been edited and condensed for clarity. *

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