Data explainer: UK student cases of COVID-19

Natalie Parks

Daily updates:

Sept. 2

New cases today: 89 (single day high for UK students)

Total since Aug. 17: 649

Minimum active cases: 405

Total since March: 880

Sept. 1 

New cases: 31

Total cases since first day of classes (Aug. 17): 560

Minimum number of active cases: 530*

*Calculated by subtracting the number of total cases from 14 days ago from the current number of total cases, because 14 is the minimum number of days UK students must wait to be cleared.

Positive cases among UK’s student body are on the rise, but the actual data on the number of cases can be confusing.

UK’s COVID-19 reporting page ran on a three-day lag, and currently shows results from Phase I of testing, which was mandatory testing for all students within seven days of their arrival on campus. This page only includes results from students who test positive through UK’s testing partnership with Wild Health. The page currently shows 254 positive results, and has not been updated in nine days, since Phase I ended on Aug. 22. UK’s page says results for Phase II (which began on Aug. 23 with the retesting of 5,500 Greek life students) will be available “in the coming days.”

However, the Lexington-Fayette County Health Department updates their UK student numbers every day and includes students who test positive through other testing services, not just with UK. One caveat – LCFHD numbers only include students who are Fayette County residents OR students who choose to remain in Fayette County for their quarantine period. So, if a student from another county or state chooses to return home after they test positive, their positive result is not included in LFCHD’s numbers. Still, LFCHD’s daily updates are both more accurate and timelier than UK’s COVID-19 reporting page, so I will be using the LFCHD data here.

(You can visit the LFCHD site and check their daily updates here)

I have been checking the daily update and tracking the UK student cases in Excel since Aug.17, the first day of classes. But LFCHD has been reporting UK student cases since March, so the total that they update every day includes all student cases from March until now. To get a more accurate number of cases, we will do a little subtraction.

The daily update for Aug. 31 said a total of 760 UK students had tested positive for COVID-19. 760 sounds like a lot. But, a LFCHD spokesperson confirmed to me that between March and Aug. 3, 121 UK students had tested positive for COVID-19. So, the total number of recent cases is actually 639 (or 760 minus those 121). The word “recent” here refers to cases since Aug. 3, when UK began testing, and was also the same week that students began move-in.

Still, 639 cases are noticeably higher than the current data on UK’s page, which shows 254 cases for the same period of time, since Aug. 3. That’s a difference of 385 cases between what LFCHD has reported in the last month and what UK has reported in the last month.

So, 639 students have tested positive in the last month. However, that number is split into two very important categories – cases before classes began and cases after classes began.

As of Aug. 31, 529 cases were reported since the first day of classes, which is 83 percent of UK student cases reported in the last month. I calculated this by subtracting 231, the number of cases from LFCHD’s update the day classes started, from 760, the total as of Aug. 31. 529 is also the minimum number of cases we can assume are active, explained below:

Neither UK nor LFCHD are reporting explicitly student recoveries, so we don’t know how many cases are active – but, we can get closer to that number using the guidelines for students’ release out of quarantine.

According to UK’s restart plan, student isolation can end after 14 days if the student is fever-free for at least three days and shows improvement in respiratory symptoms.

As of today, 760 students have tested positive. Tracking back 14 days, the number we need to calculate active cases is from Aug. 17, a day that LFCHD reported 231 total cases among UK students. Assuming students are getting cleared after 14 days, then the minimum number of active cases is the number of cases that have occurred since Aug. 17, which we can calculate by subtracting 231 from 760. That gives us 529, which again, is a minimum number of active cases that assumes students are being cleared after two weeks. Because no one is reporting student recovery numbers, the actual number of active cases could be above that if students are not recovering within 14 days.

So what have we learned? The daily updates from LFCHD includes cases since March. The daily total from LFCHD (for example, 760 for today) is thus not an accurate number of current cases and isn’t helpful for analyzing trends among UK numbers. To get a better look at cases in the school year, we can either subtract 121 from the daily total to get the number of cases since Aug. 3, or we can subtract 231 from the daily total to get the number of cases since Aug. 17, when classes began.

We learned that as of Aug. 31, for all of 2020, 70 percent of reported cases among UK students have happened since Aug. 17, the first day of classes. And, we learned that of the 639 cases among UK students since UK’s testing began on Aug. 3, 529 (or 83 percent) of those cases are since the first day of class.

We learned that the daily update for Saturday, Aug. 29, was the single highest daily increase for UK student cases since classes began.

529 (not 760) is the most likely, most real number of current student cases connected to UK’s campus as of Aug. 31. Allowing some wiggle room for slower recovery times, the actual number of cases could be around 560, or higher, but is probably not greater than 639 (the number of student cases since UK’s testing began on Aug. 3). But 529 is the number we should be watching, as it is the number of cases since classes began.

In the future, the LFCHD is the most reliable source to watch UK’s student case numbers, but remember that the daily update includes cases prior to August and thus subtraction is necessary to get a clear understanding of how many cases are current and active. LFCHD updates around 9 a.m. Monday through Saturday; Monday’s numbers include positive results from Sunday.

The governor’s updates on college students include numbers from other Kentucky colleges, not just UK, and run on an unspecified lag behind local health departments like LFCHD because the state draws from multiple sources.

The Kentucky Department for Public Health posts data from all colleges in Kentucky and does report recoveries.

Currently, the update posted on Sept. 1 says that a total of 677 UK students have recovered after testing positive for COVID-19; it is unclear if the timeframe for those recoveries goes back to March and if it includes only residents of Fayette County or residents of Kentucky.

The Sept. 1 data posted by DPH reports 407 active cases and 372 new cases among UK students. The total number of cases among UK students reported by DPH is 1084, which is higher than the LFCHD’s total of 791 as of Sept. 1.

All data from the Lexington Fayette County Health Department’s daily updates, which the writer has been tracking.