Duke releases COVID19 testing for athletes-what does it mean?

Duke released information last night that 25 student athletes have tested positive for the SARS COV 2 virus since they began a phased return to campus on July 12, 2020.

Nine student athletes are currently in quarantine, while 16 have been cleared by physicians to return to normal activity (I believe that means they tested positive at least 14 days ago, but that is an assumption that the quarantine is 14 days; the CDC is now saying 10 days). It is also possible that a student athlete tested positive and then negative and was cleared by a physician, I am unsure. Thankfully, none of the 25 student athletes had anything other than very mild symptoms and most were asymptomatic according the press release.

700 total tests have been provided to 309 “student athletes, coaches and staff” and no coaches and staff have tested positive. It is not stated how many of the 309 tested are student athletes versus coaches and staff; we know the rate of coaches and staff positives is zero, but cannot estimate a rate for student athletes with precision.

What do these data mean, and what evidence does this experience provide for the the overall campus reopening that begins on Thursday, August 6? It is difficult to say given how the data were released, but here is what I think that we can glean from this statement.

**No staff or coaches have tested positive since July 12, 2020 (unclear what the denominator of coaches and staff is). This is good news, as one fear of reopening is that there will be community to campus and campus to community transmission of SARS COV 2. I hope we can sustain that into the Fall, and this type of information needs to be clearly communicated.

**25 student athletes (unclear how many of the 309 are student athletes) have tested positive since July 12, 2020. According to the release “the majority of students testing positive” tested positive upon arrival at Duke. So, up to 12 student athletes had an initial negative test and a subsequent positive one at some point in the last 19 days. If I had to guess (which you have to do given how the data were released) I would guess 13 were positive on arrival given adjective choice “the majority of” and not an adjective like “the vast majority of.” Going with that assumption, 12 student athletes tested negative and then positive. Note that a negative test upon arrival and then a positive test later is not necessarily proof of transmission on campus given the reality of testing, but Duke’s testing is being done in-house and is of the highest possible quality. The pooled testing approach that has been pioneered by Duke is a strength we have in this situation.

**25 (total student athletes testing positive) divided by 309 is about 8 percent. 12 divided by 309 is 3.9%, which is the highest possible rate of student athletes testing negative and later positive based on the releases notation that “the majority tested positive upon arrival.” Let’s just say 4% tested positive on arrival, and 4% tested negative on arrival and later tested positive, but this rate has uncertainty in the both the numerator as well as the denominator given how the data were released.

I am unsure if this is a lot, a little, or as expected? It is best understood simply as a first data point of Duke’s experience in testing student athletes. I do assume that we will have more control over student athletes than we will have over all students, but of course that is nothing more than a testable hypothesis.

If 3,000 first year and second year students return to campus starting August 6 (which assumes ~500 do not show up), for the first day of class of August 17, a 4% rate of testing positive upon return would be ~ 120 first and second year students. Using the student athlete testing data as a predictor, then a similar number of ~120 first and second year students would have a negative test upon arrival on campus and positive one within 3 weeks or so. Of course, the denominator of students on campus will be more than 10x the total number of people being tested in the first 19 days of the student athlete protocol of 309 athletes, coaches and staff.

Duke should provide more data on testing, cases and transmission as we reopen the University, and we can do so in full compliance of HIPPA, even without invoking public health exceptions. Our ethos of “Knowledge in the Service of Society” and our position as a top 10 research university assumes, expects and requires more transparency in the midst of a Public Health emergency.

As I am known to say in numerous contexts, “free the data!”

Post Script–Just after I hit send, I thought of another key uncertainty with the data release. It is unclear if the 700 tests were 700 individual tests, or if they were using the pooled sampling method that will be used for surveillance this fall. Under pooled surveillance, you would test everyone on a dorm floor, for example, and if the pooled sample is positive, then you test the B sample collected at the same time for each individual on the floor. If the 700 tests means many pooled samples with follow ups, that is tons more surveillance than 700 individual tests. I am unsure of what they did based on the release.

About Don Taylor
Professor of Public Policy (with appointments in Business, Nursing, Community and Family Medicine, and the Duke Clinical Research Institute), and Chair of the Academic Council at Duke University https://academiccouncil.duke.edu/ . I am one of the founding faculty of the Margolis Center for Health Policy. My research focuses on improving care for persons who are dying, and I am co-PI of a CMMI award in Community Based Palliative Care. I teach both undergrads and grad students at Duke. On twitter @donaldhtaylorjr

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