Darlene Bhavnani and Bill Kohl – Flattening the Curve with Contact Tracing

M. Yvonne Taylor
July 1, 2020

Darlene Bhavnani of Dell Medical School and Bill Kohl of the College of Education join Talking Eds to discuss the importance of contact tracing for containing infectious disease, and how uneven policies and ongoing protests can complicate efforts to flatten the curve.



Yvonne: Hi, and welcome to Talking Eds, the podcast for all things education, produced by the College of Education at The University of Texas at Austin. Since mid-March, Dr. Darlene Bhavnani, epidemiologist in the Department of Population Health at Dell Medical School, and Dr. Bill Kohl, professor of Kinesiology and Health Education of the College of Education, both at UT Austin, have been part of a team of medical personnel and academics responding to the challenges of the COVID-19 pandemic. In particular, both of them working on contact tracing.

Today, we're going to talk a bit about contact tracing, what it is, why it's important, and also about how the reopening of states and the current social unrest may be further complicating the efforts to flatten the curve. First of all, thank you both for being here with us today. Dr. Bhavnani, you're still relatively new to Dell Med and UT Austin, can you give us a little bit about your background and how you came to be here?

Dr. Darlene Bhavnani: Yes, so I'm an infectious disease epidemiologist. I've worked in global health for over 10 years, and I spent the last five years working in Central America helping to eliminate malaria. So, I was working to eliminate an old disease that has been around for over 100 years. And now I find myself at UT working at Dell Med, and it's the opposite. I'm working very hard on COVID-19 to control a very new disease.

Yvonne: Thank you. Dr. Kohl, can you share your focus of your work?

Dr. Harold W. (Bill) Kohl, III: Certainly, Yvonne. While Dr. Bhavnani is new and has a lot of new ideas, I've been around a long time. You might wonder why a professor of kinesiology is interested in infectious disease. I'm also a professor of epidemiology in the UT Houston School of Public Health in the Austin campus. And I also worked for CDC for some years in Atlanta, which gave me the background and interest in infectious disease that we're able to bring to this current crisis right now.

Yvonne: And how large is your team right now? How many folks are you working with?

Dr. Darlene Bhavnani: Yeah, so right now most of our contact tracers, I would say, are volunteers. We do have some reassigned Dell Med staff and we’re working with the University Health Services, with some of their stuff as well, but I would say the majority of them are volunteers. We just recently scaled up from a size of 100 contact tracers on our team. Now we've opened that up to 150 to 200. So, we're looking to train more and more people each week to keep up with the growing number of cases in Austin.

Yvonne: Wow. So, let's go back a little bit to earlier this year. It's my understanding that the dean of Dell Medical School, Clay Johnson, kind of had his eye on the issue a little bit early, and was being in front of contact tracing from around January/February. Is that right?

Dr. Darlene Bhavnani: Yeah, I think we were inspired, and him in particular was very inspired with what some of these other countries in east Asia were doing. So, South Korea, China, and others, in the way they were doing the contact tracing. So, inspired by the success that we saw in other countries, Singapore included, I think he recognized the need very early on, and was very supportive of us developing a small contact tracing team that started off very small on campus, just around the cases that were coming to us in the UT community. And we grew, we grew to fulfill a need that existed and we're happy to be doing that today.

Yvonne: So, let's talk about contact tracing itself. Can you walk us through the process involved?

Dr. Darlene Bhavnani: Sure, absolutely. So, contact tracing starts when you have a lab-confirmed positive case of COVID-19. It's a technique that's been used by public health officials and practitioners for many many years with other infectious diseases such as HIV, TB, and others. So, it's not new but it does start when you have that lab-confirmed positive. So, it's dependent on having very good testing. Once we have a notification of a case, we get on the phone and call that person, and we talk to them about when their symptoms began. We try to understand when their symptoms started because with this particular infection, we understand the infectious period to have started a few days before symptom onset, so that's two days before and then 10 days out. That time period really represents their most infectious period, when they might have actually transmitted the infection to others. So, we try to talk to them about what they did during this time frame, where they went, who they may have been in contact with. We try to get information about those contacts, including the names and the phone numbers of those individuals, and then we follow up with those specific contacts by calling them and talking to them about exposures, when that exposure happened, how long we expect them to quarantine or isolate should they be feeling sick, and try to link them up to resources to either get tested or set them up for success as they quarantine.

Dr. Harold W. (Bill) Kohl, III: And Yvonne, one of the best examples of the system that Dr. Bhavnani put in place was just published this week in the publication of the Centers for Disease Control and Prevention, the Morbidity and Mortality Weekly Report, there is -- I'm sure she will talk about it -- but there was a cluster of UT Austin students, an outbreak, a cluster of cases among a group of students who went to Cabo San Lucas for spring break, and came back and started to have contacts with roommates, with community contacts and others, family. And with this aggressive contact tracing, they were able to minimize the, I guess leakage, if you will, to others -- the infectious period to others -- and contained the outbreak fairly rapidly. That, I think, is a model for, as they pointed out in the paper, is a model for opening schools in the fall, what to do, ramp them up and be ready with contact tracing as soon as it happens because you never know when the next outbreak is going to be, and it's a very potent tool in the epidemiologist’s toolbox to help contain disease outbreaks.

Yvonne: I'm glad you mentioned the opening up of schools because that's obviously on so many people's minds. I've got a 14-year-old as well who's eager to start 9th grade and to start high school, and to actually play sports. And so, we don't know what that's going to look like. I know that when you started your work, most of the states were on a pretty tight lockdown, and I would imagine that that makes the contact tracing easier to do because people aren't milling about in lots of different scenarios and places. Can you talk a bit about the environment now that states have opened up as much as they have, as well as like, the protests and things and the unrest that has happened in the country, does that complicate the contact tracing?

Dr. Darlene Bhavnani: So, I would just say that contact tracing is really focused on those close contacts, and for public health practice purposes, we follow very closely the CDC definition of a close contact, so that's 15 minutes within 6 feet. But you know, physical contact such as a kiss or a hug I mean, that would qualify to our contact tracers as being close as well. So, any kind of activity or movement that increases the number of close contacts and potential for transmission just really complicates our tracing as well, makes everything a little bit more difficult. So, as we think about reopening communities and reopening schools, I think we just have to keep that in focus and make sure that we're doing as much as we can to limit the potential for transmission. You know, things like sanitization, hand washing, masks, are important, but really it's that distance that's really going to make a huge difference as well. So, just making sure that we're opening as safely as possible is going to be really important. Saying that, those are individual level things that can be done, but I think at a higher-level, making sure that we're very supportive of our cases, we're making sure that we're doing good, active case detection on campuses and in schools. That includes screening but also testing and making sure that we have the infrastructure and the resources in place to be able to act upon that data that's coming in from those cases being tested and either contact trace, like we're doing here right now, or investigate. Identifying and investigate clusters is going to be extremely important as well as just looking at the data, making sure we're following the data and using the data to the best of our ability to make the best decisions possible.

Dr. Harold W. (Bill) Kohl, III: One of the really confounding things about COVID-19, or the coronavirus that results in COVID-19, is the asymptomatic and pre-symptomatic transmission of the virus. Many times when you're sick you know it. With this particular virus, the best data we have are that there may be up to 40% -- certainly close, maybe somewhere between 20% and 40%, of people -- of cases who don't know they're sick, and therefore don't see a need to isolate or self-isolate or even quarantine themselves during that time period, and that's one of the more frustrating parts of policies that allow for gradual re-openings and so forth is that even people with the best of intentions. "I feel fine, I'm going to go out," may not know that they're carrying or shedding the virus. And so, policies, whether they're institutional policies, city or municipal policies, or state policies, they have to take that into account, and testing, tracing, and isolation is the mantra, I think, that until we have a vaccine, which is not likely going to be for the next year or so at least, maybe half a year from now, we've got to continue to invest in those resources to try to get that done.

Yvonne: Thank you for that, you just said "testing, tracing, and isolation," I think I heard you describe that before as like the "three-legged stool" that's needed in order to flatten the curve, is that correct?

Dr. Harold W. (Bill) Kohl, III: Yes, and it's absolutely critical, and early on we were low on testing. Testing kits and so forth are now a little bit more available; there's saliva tests instead of nasal swabs that are starting to appear, but it's still -- the recommendations have evolved now. Usually it was if you're sick you might be eligible to be tested a few months ago, now with more testing available, there's a lot of asymptomatic people who are going to get tested as well, and that's probably a good thing, particularly if 20% to 40% of people don't know they are carrying the virus.

Yvonne: Right, my final question for you both is, what advice would you give to those who either must go out and be in the public, or feel compelled to in order to participate in demonstrations that they believe are vital to social change?

Dr. Darlene Bhavnani: So, I would say to think very carefully about that because as soon as you're stepping out of your house, you're not just putting yourself at risk but you're putting others in the community as risk. So, I would just weigh those risks very carefully, but I would also say that there may be alternative ways to protest from your home. I know that just released in the media was a list of locally-owned businesses by African Americans or Hispanic community members. You know, finding other ways to protest can be just as powerful without having to put yourself and others in your family or in your community at risk. So, I would say that's something to keep in mind. At the same time, as much as we can physically distance, I would say, if we're out there wearing masks, just trying to protect yourself and others from that transmission can really also help if you must go out.

Dr. Harold W. (Bill) Kohl, III: Yeah, assuming that most protesters are younger individuals who might not be as risk for the disease compared to older individuals is a false assumption. Young people, meaning 20 to 35 or so, are not as at-risk for as serious or a hospitalization due to the infection as other but there's no evidence that they're in any lower-risk of actually getting it so, isolating -- you know, this is as old as infectious diseases (laughing), quarantine, isolation if you get symptoms or get sick, and limiting your interactions is the only tool -- are the only tools we have right now, hand washing, masks, those kinds of things. And I agree with Dr. Bhavnani, think twice about protesting in a large group of people, certainly the social issues we're facing these days are absolutely critical to bring attention to and to change, but there are likely other ways that the systems can change without exposing you or your family to a disease that is terrible. It doesn't discriminate among young vs. old, Black vs. white, others.

Yvonne: Thank you for that, thank you. Dr. Bhavnani and Dr. Kohl, thank you so much for taking the time to talk with us today. I know you're both extraordinarily busy, and thank you to our audience for listening to our podcast, Zoom cast. If you'd like to hear more Talking Eds, please visit us at www. https://incontext.education.utexas.edu/ Take care to all of you, and stay safe.