How does contact tracing work in the NFL? Here are the answers

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One prediction I feel very good about making: Without a significant and advanced system of contact tracing this fall, the NFL would have had to postpone or cancel games by now. Yet here the league is, 14 weeks in, and zero games to make up. “The contact-tracing element is absolutely foundational for us,” the NFL’s medical director, Dr. Allen Sills, told me Friday. “It’s the element that almost nobody is talking about.”

Contact tracing has become increasingly important as the season progresses and COVID-19 increases around the country and in the player population. In September and October, 47 NFL players tested positive for COVID. That number shot up recently. From Nov. 1 to Dec. 5, 111 players were positive. More cases, more chances of spread. And more reason to emphasize the identification and isolation of COVID-positive people. The NFL, as of Friday, had discovered 24 new cases of the coronavirus through tracing of high-risk close-contacts with those NFL employees previously testing positive. That is according to Dr. Christina Mack, an epidemiologist for IQVIA, a long-time NFL partner in health research and technology, and now in contact tracing. She has worked closely with the NFL this season.

Dr. Mack gave an illustration of how the contact-tracing program works. There are a few provisos: Privacy laws prevent the NFL from using an example with names and teams, so for the sake of the exercise, I will use The Team, and Player A and Player B. She would not provide exact dates of the illustration, so I will use Day 1, Day 2, etc. She would only say that this scenario occurred within the last month, as cases around the league have spiked.

Day 1, evening

Player A, driving, carpools home with a teammate from a full day at practice with The Team, having a conversation of about 12 minutes with the teammate when he drops him off. Player A arrives home around 6:30 p.m.

Day 2, morning

At 7:30 a.m., Player A arrives at The Team facility and his nose is swabbed for the daily COVID-19 PCR test. A normal practice day ensues.

Day 3

At 6:30 a.m., when Dr. Mack wakes up, her phone already has text alerts of any positive tests among the players or team employees (coaches, training and equipment staff) with daily player contact. These tests of about 70 players per team (plus coaches and team officials) were swabbed the previous morning. She sees Player A of The Team has tested positive from his test on Day 2. The rest of the NFL’s COVID team, led by Dr. Sills, plus officials of The Team, also get this data. An official of The Team contacts the player and tells him to isolate and not report to the club facility—and to expect to be debriefed by a league contact tracer about all his contacts in the previous three days. “The team will ask, ‘Are you okay? Are you isolated? If you’re at home, make sure you’re isolated from your family,’ “ Dr. Mack said. “And they isolate everyone who is about to get contact traced.”

At 7 a.m., Dr. Mack and a team of four to six tracers meet by conference call to discuss that day’s positives. Dr. Mack and the tracers have to look at results from the player’s tracking device on Day 2, when he was contagious and spent the day at the facility, plus two days prior. They do this because even though the player didn’t test positive on the previous two days, he may have had the ability to spread the virus on those days. Each player while at the team facility wears a Kinexon tracking device from the time he walks in till the time he leaves for the day, and it shows who the player has been closer than six feet to during the time he is at the facility or at practice. In examining the player’s device over the previous three days, Kinexon shows the player had eight contacts on the day he tested positive, seven contacts on the previous day, and two contacts on the previous day to that. Some of those people—depending on the time and area of contact—will be contacted by the tracers. While this is happening, The Team decides to close its facility and work remotely till the tracing has occurred.

At 8:30 a.m., what Dr. Sills calls “the SWAT team,” a group of about 12 doctors, epidemiologists, infectious-disease experts, league officials and tracers, meet by conference call. (This meeting happens seven days a week, an hour earlier on Sundays.) “We go through each case that day, and put together a pod team for that case,” Dr. Mack said. For the pod investigating Player A, there will be an IQVIA tracer, an NFL-employed tracer, and a physician who is an infectious-disease expert.

A big part of the process is interviewing The Team’s Infection Control Officer (each team appointed one to start the 2020 season) to get an overview of Day 2, to see where more questions and interviews might be needed.

“The individual came in at 7:30 a.m.,” Dr. Mack said, referring to the day of the positive test. “There was a team meeting but it was in the bubble, which is a well-ventilated area. They had a lift session so we walked through the map of that lift session. Everyone was spread out. They were more than six feet apart, heavily ventilated room. Everyone had been wearing masks per protocols. The team had a walkthrough [a light practice]. They had lunch. The lunch tables are one chair per 10 feet apart. We went through the walkthrough again. The practice goes from 2:15 to 4:10. Everyone was spaced out and masked during that time. And then they actually had a night meeting which was 45 minutes and the [infected player] was there until 6:15 p.m. We walked through that entire day and asked about contacts at each point, masking at each point. Did you drink coffee or have a snack or eat food at any point? Which suggests the mask would be off.”

At the beginning of the season, the NFL defined “close contacts” as being within six feet for at least 15 minutes. Not anymore—because the CDC has deemed that too many factors can impact the strict definition of close contact. Tracers now would be concerned with a 5-minute, unmasked and indoor conversation. According to Dr. Mack, “The real art with the contacts is the interview. It has to be thoughtful and thorough.” It can last from 20 to 50 minutes, or longer, with questions like: Was your contact with the infected player inside? Outside? Were you masked? Were you eating? Drinking? Was the mask off for part of your contact?

It turns out, after the interviews conducted by the two tracers doing the investigation into Player A’s contacts, one was deemed a “high-risk close-contact.” That player, Player B, by league rule will have to stay away from The Team facility for 5 days.

When the tracers interviewed Player A, he mentioned a contact with a teammate on the evening of Day 1, driving home. In an interview with one of the contact tracers, Player B’s story matched the details of Player A about the carpool drive.

“It was an estimated 5-minute drive,” Dr. Mack said.

Two problems, per Dr. Mack:

“They had the windows up, and they were unmasked.”

Said Dr. Mack: “When they got home, they went outside and they talked for 12 minutes approximately, and then parted ways. That was the contact on that day that was noted as a high-risk close contact. In this example, at the facility, all of the protocols had been followed, distancing was done, masks were worn. The facility was set up in ways that tables were far apart, chairs were far apart, meeting rooms were well-spaced, they were in well-ventilated areas. We did not have any high-risk close contacts from the day in the facility despite interactions with the team all day. None of those individuals turned positive. But we did detect that high-risk close contact from the shared car ride home.”

Day 4

Player B does not test positive.

Day 5

Player B tests positive, four mornings after the maskless, closed-windows car-ride with Player A.


“This has been an evolution, an ongoing learning process,” Dr. Mack said. “So with this team [the prior week], we had gone through the data and we said, ‘You have a really high number of close contacts at 3 o’clock on a Wednesday. What is the team doing at 3 o’clock on a Wednesday?’ And they said, they’re in the locker room. They’re coming in and out of practice at that time and they’re in the locker room. We said okay, let’s go through and look at the schedule. Who’s in the locker room? And as we went through that exercise the week prior, we learned that the position groups had lockers close to each other and talked through with the team that if they changed the placement of the lockers to make it so the position group lockers were very much spaced apart, they aren’t going to be near each other and they’ll reduce their number of close contacts. After that meeting, this team changed the placement of the lockers. It was really well-timed because when this case came up, they had just moved all of the lockers and so they did not have contact in the locker room at that time between these people. It felt like a bullet dodged.”

I wondered if, in this case, limiting the spread to one player through contact tracing was a Eureka! moment for Mack and her three-person pod of tracers.

She paused, and answered it this way: “If there’s a positive case, keep one case to one case.”

Read more from Peter King’s Football Morning in America column here.