Watch: An Infectious Disease Specialist Answers Your Questions About Contact Tracing

Jun 10, 2020

KUT's Jennifer Stayton hosted a live conversation Wednesday about contact tracing with Dr. Parker Hudson, who leads the contact tracing team at UT Health Austin. Contact tracing is the work of identifying and isolating possible cases of a disease like COVID-19.

Austin has hundreds of people working to identify those who may have come into contact with people with confirmed cases and warning them to stay isolated and get tested. 

Every Wednesday at noon on our livestreamed series Now What?, KUT reporters talk with leading scientists, researchers and thinkers from across UT Austin about what we need to know about COVID-19 moving forward.

Interview Highlights

Note: This transcript has been edited lightly for clarity. To hear to the full interview, watch the video above.  

KUT: So, first of all, if you could just define contact tracing. Exactly what is that? 

Dr. Parker Hudson: Contact tracing is a very basic, fundamental public health intervention to stop the spread of an outbreak or an epidemic. What it entails is finding people who are infected with, in this case, a virus, and isolating them. Just separating them from society temporarily, at least physically, hopefully not socially, to protect the public from that contagious disease. 

In doing that, we ask them for who else they could be in contact with. Then we follow up with those contacts. Those people we're assessing to see if they were exposed and exposed in the right way, depending on the infectious diseases, which in some cases of contact tracing, may be a sexually transmitted infection. In this case, obviously, it's primarily a respiratory infection.

Then we ask the exposed people — if they were exposed during the infectious period of the virus — to quarantine themselves. Again, to separate from the rest of the rest of society temporarily, to monitor themselves, to see if and when they become infectious because they were exposed to the virus. 

KUT: I thought it was interesting that contact tracing is actually not a new tool. We've been hearing about it a lot in relation to COVID-19. But tell us a little bit about the history of contact tracing and circumstances where it's been used before. 

Hudson: Yes, it is a tried and true and one of the few clear interventions we have outside of shelter-in-place-type orders. Obviously, social distancing, masking. These are the other important public health efforts that we can come back to. 

But beyond that, it is a very basic approach to public health and has been used for a long time for tuberculosis. It had a part in the eradication of smallpox. It's used now related to sexually transmitted infections as far as HIV and syphilis. When we have individual outbreaks of, say, Legionella or a mumps case or measles case. Public health organizations have been doing contact tracing for specific outbreaks like that and for more continuous epidemics like HIV for a very long time. 

Most recently, it's been used and was very effective in controlling SARS, the previous form of coronavirus that through contact tracing we really were able to contain and then eradicate. We were able to break the chain of transmission. 

If infected people are known and aren't able to pass it on to other people, and those people that were exposed are also protected from passing it on to other people, the virus can't propagate itself. It can't keep going. And thus we haven't seen SARS in 15 years. Likewise for MERS and then most recently for Ebola. It played an important role in eradicating or controlling the 2014 Ebola outbreak in West Africa. So a lot of rich history. 

WHO, CDC, state and local health departments all have experienced protocols, guidelines and expertise in what is a fundamental public health response to a pandemic. 

KUT: Who is we? Who is actually doing the calling and the interviewing in contact tracing? 

Hudson: Many people feel like contact tracing, like I said, is a human-to-human interaction to be done most effectively. There's a lot of discussion around technology and apps that can help do some of the tracing, including the Bluetooth technology and geolocalization. 

The "we" is not a robot or, you know, eye in the sky. The "we" are UT employees and staff who have offered to be reassigned to support this effort while normal operations are not in effect. In addition, we have volunteers who've been trained, have agreed to a level of privacy and security to be able to do this work as public health professionals. So that is our current pool of "we." Obviously Austin Public Health has an entire epidemiology division that they're also building and growing, who is the "we" for Travis County as well.

KUT: It depends a lot on people being very forthcoming with where they've been and who they've seen, what they've done. When we've been under more of the stay-home work-at-home rules, that hasn't been quite as difficult to do because people didn't have as much contact. But businesses are opening up. People are starting to be out and about more. If somebody attended one of the recent protests or demonstrations and then they test positive, I mean, how on earth do you do contact tracing for somebody who was around a lot of people, and they don't even know who they all are? 

Hudson: Yeah, that is a particularly challenging situation, especially outdoors in places that you may not know all the people around you. Some people in some other countries have advocated for use of the Bluetooth technology to be able to collect and identify those people more rapidly. We are not doing that to be clear. We likely are missing people in that large environment. 

In that environment, I think it's more about the messaging, making sure that you're rapidly getting tested and that the contacts that you do have are identified and also contacted for testing and for quarantine. 

It's a lot different if you're talking about other types of interactions than just that sort of public outdoor event. For example, in a church or other religious gathering, you can reach out and find out and go through the organization to let them know what service somebody was positive in to let their members know. Similarly, in other environments. Restaurants may know who was on their reservation list during a specific time, if there was concern there. 

There are ways around the sort of general public not knowing. Other strategies that we have not implemented but Germany's doing and other places that have been successful: when you go to businesses writing down your contact information so that if a case comes up, you can more readily be identified. Again, people have concerns over privacy, which we fully respect. And this is private information, but it's also that sort of the spirit of public good, that we're all better off if we share this and if we share it with the public health professionals who are trying to keep us safe.

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