Many of the schools in Alabama are part of a program called GuideSafe. All students had to take a COVID-19 test within 14 days prior to returning to campus permanently. On paper, without the details, this was a decent process (assuming that the students didn't do stupid things). After classes began, sentinel testing will look for undetected infections.
[For those who go by TLDR: I believe a significant contributor to the problem was self-swabbing by students for samples used in the testing before returning to school.]
The most notable schools are the University of Alabama (at Tuscaloosa) and Auburn University Main campus.
Auburn has 71% of the students as UA. I would expect the student populations to be roughly similar
in geographic and diversity measures.
University of Alabama (students @ Tuscaloosa only)
Reentry cases (tests within 2 weeks of return to school)
311 (29,938 tested) 1.0% positive
Date range Cases
1/1 - 8/18 158
8/19 - 8/24 562 (6 days; 0.31% per day) Classes began Aug 19.
8/25 - 8/27 481 (3 days; 0.54% per day)
8/28 - 9/3 846 (7 days; 0.40% per day)
For a total of 1889 since classes started. (1889 is 6.3% of 29,938)
Auburn University (students @ main campus only)
Reentry cases:
859 (21,315 tested) 4.0% positive
Date range Cases
Aug 8-14 32 (7 days)
Aug 15-21 202 (7 days; 0.14% per day) Classes began Aug 17
Aug 22-28 490 (7 days; 0.33% per day)
Aug 29-Sep 4 [not available as of 9/5]
Roughly 692 since classes started. (692 is 3.2% of 21,315)
I believe the reentry testing procedures were basically the same for these two schools. However, as you see, the % positive were vastly different for the reentry tests. Remember that while reentry testing was universal, subsequent testing was (mostly) for students with symptoms or students that knew they were exposed and went in for testing. There are probably many undetected cases in the student community.
(As we see in communities across the US, HIPAA laws are preventing people from being notified when they may have been exposed, or less generously, HIPAA laws are being used as an excuse to avoid telling potentially exposed people. At UA,
professors were warned not to tell their classes if they became aware that a student in their class was infected. While the claim is that masked & socially distant students in a class don't constitute an exposure risk, there were no measures to assure the masks were properly worn, weren't leaky, and were worn when socializing before or after or otherwise outside class.)
If one believes the rate of spread of the infection ® for the two student populations was approximately the same, you would come to the conclusion that there were more cases percentage-wise at UA than Auburn on the first day of school. This would explain the higher percentage rate of new cases at UA vs Auburn.
Unfortunately, the test result periods for the two schools neither line up to each other nor to the start of school. In terms of exposures, the actual date that classes start is less important than the dates that students returned to the dorms or off campus housing.
Both schools show a very large percentage of cases. In the one month from two weeks before classes, about 7.2% of the students tested positive (with the typical notice about undetected cases).
If we assume R of 1.0, this would suggest virtually all of the student body will have COVID-19 before next year starts.
The UA outbreak of 562 cases got a lot of coverage beginning August 24, and administrative reaction. If all of the 8/28 - 9/3 cases had a 5 day period from exposure to date of positive sample, then they were exposed 8/23 - 8/29. I'm hoping that next week's numbers show a big drop due to the feedback of attention to the outbreak.
Auburn's 4% positivity rate
was characterized as "low" by the school, even though they were 4x the rate at UA! “These numbers show we had a low positivity rate among our students as they returned to campus,” said Fred Kam, Auburn’s Medical Clinic director.
To give some perspective, the 8/28-9/3 week at UA, if projected to the population of NYC would correspond to more than 33,500 cases a day. The Aug 22-28 week at Auburn would correspond to 27,250 cases a day. The maximum daily case rate at NYC by 7-day rolling average was about 5300 cases a day. (To be fair, the number of actual cases in NYC was likely vastly undercounted. The actual cases at the schools was likely undercounted a lot less than NYC.)
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I expect the schools and the state felt that the GuideSafe program of reentry testing would minimize the number of active cases in the student community as of the first day of classes. Then, the schools would try to keep the spread down by sentinel testing. Certainly at UA, and to a lesser extent at Auburn, that didn't happen. I think the US as a whole expected this of its response to COVID, but
the schools didn't learn from their country's failure to contain COVID-19.
So, what went wrong? Should it all be blamed on the student behavior (going to bars & partying)? Or was the devil in the details? If the reentry testing was prone to false negatives, the number of cases on the first day of classes may have been much higher than expected.
The rate of growth of the infection, R, is very dependent upon behavior of the population. Throughout the US, cities are struggling to keep R below 1 with masks & social distancing and the banning of high risk activities. Early in the history of COVID-19, R has been set around 2, to maybe 6, in different populations before controls were introduced. I will estimate R at being the ratio of new cases in a week over the cases in the previous week.
There could be some that got infected after reentry testing but before returning to school, but with the (student) community rate of about 1% at UA, I wouldn't expect too many. Maybe I'm wrong. If PCR normally detects up to 3 weeks after infection, you might expect about about 100 new cases in the average of 1 week before school testing (average of 0 to 2 weeks). (104 = 311 * 1wk/3wk) If 100 cases turned into 562 in a week (about one period for the disease to spread to others), that would suggest an R of 4.6.
I wondered if Alabama used the (so-called "breakthrough") antigen test that the PAC-12 athletes are to be given, it has (as best I've found) 1 out of 8 cases will get a false negative.
With that test, if you found 311 cases, there were probably about 311 * 8/7 = 355 cases, meaning 44 were missed (false negatives). (If 44 cases turned into 562, R would be about 11.8.)
Alabama allowed for the antigen test, and even provided it. Here are some snippets from UA communications about the testing required/provided.
Aug 4 Student Testing Update:
Quote:All students must provide a negative COVID-19 antigen or PCR test result before returning to campus.
Testing is conducted in one of three ways:
On-site testing locations (13 sites across Alabama)
At-home testing kits (limited availability; primarily for out-of-state students who live on campus and those who do not have access to a testing site before returning to campus)*
Student tests at an alternative testing location
Aug 10 A Message from Dr. Richard Friend, Dean of the College of Community Health Sciences
In it, he indicates they were using a POC test with results in 15 minutes (ie, the antigen test) for faculty & staff. But the testing of the students on campus (apparently prior to the start of school) was being done with PCR tests.
"As the fall semester continues, CCHS will conduct sentinel testing – regular testing of approximately 4% of faculty, staff and students across campus. This will help us keep informed about Covid-19 infection rates on campus and help identify potential virus hotspots. In addition, University Medical Center, which the College operates, will continue to provide daily Covid-19 testing for those exhibiting symptoms and who need a rapid result." (ie, antigen testing once school started)
Aug 11 Student Messages
This message indicates that students who had not yet been tested needed to register and request a test at one of 13 locations across the state. But then, it says:
"The test involves a self-administered nasal swab just inside the nose."
This self-collection procedure, followed by a PCR test, is confirmed in a
GuideSafe document at Auburn.
Aha! I suspect a self-administered nasal swab is the source of likely false negatives. I have no estimate of the false negative rate for self-administered swabbing. I have seen reports that indicated that improper taking the sample is prone to cause false negatives.
But, why did Auburn have a much higher detection rate in reentry testing? I don't know. Perhaps the different (13) testing centers were more or less diligent about instructing the method to take swabs and requiring students to do it right. Maybe students tended to be tested at centers closest to their school. Perhaps UA had more at-home testing.
GuideSafe was a decent plan, until you get to the details. The state & the schools SHOULD have known this might happen, and adjusted for it.
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In the August 10th letter, the University indicated they would be testing 4% of the faculty, staff, and students as regular, sentinel testing. (I presume that is 4% in some period (a week, a month?).) I'd certainly want to know the number (percentage) of students that are testing as positive in the sentinel testing.
