The first chart below shows the positive test rates (right axis) for Nottingham and the rolling 7 day test number (you could replicate the same charts with most university towns / cities)
A similar chart below that shows again the number of tests and this time the number of positive tests recorded
The increases will have been entirely driven by students through mass asymptomatic testing on campus.
If you assume that the base rate in the ‘general population’ for +ve tests remains roguhly the same through the start of October then the +ve rate for students is probably between 40-50%
So are half the students tested (about 30- 40% of the local student body) testing +ve because:
a) Students didn’t care much about any rules or guidelines and infected each other in a week of large parties at the start of term and the rates were really that high (ONS survey data on student attitudes might suggest different)
b) The PCR testing done by / for universities was woefully inaccurate
c) Most had had the infection some time in the past and the sample rate was set so high to pick up fragments from past / dormant infections
d) None of the above
e) All of the above
I know a little bit about this. a) is definitely a factor because, despite the best efforts of accommodation providers to tell students not to mix outside their households, they could not be stopped.
I would think b) is also a factor, but also the performing of a PCR test. A lot of students were having to send off for kits because there weren't as many places you could walk into to get a test at the start of term- at least in the town I work in. When you get the test kit you unpack it, and inside is a booklet that says to read it before you unpack it. This says about washing hands, not putting the swab on a dirty table etc, but I know whole students flats were sending off for test kits and doing them all together, so if one had it, the chance of cross-contamination would be huge. Nottingham Unis were also running an asymtomatic testing programme alongside the PCR tests, which would have been generating positive results in addition to the PCR test data. Could those results be feeding into these graphs?
A third option, which I know to be a factor in Nottingham but I don't know whether it plays into these figures, is that students having to self-isolate were given food packages. Nottingham's was pretty generous, and some students were definitely declaring themselves in isolation because they knew they'd get fed for free for a couple of weeks.
Thanks for this response and really good to have a bit of local intelligence to compliment the data. I thought a) was going to be quite likely but then since posting this earlier came across this document while looking for something else. I have copied out the +ve test rates below.
As you can see they are signifcantly lower and cant believe Cambridge students are that better behaved. Though can imagine their testing somewhat more reliable.
Ps I am impressed with the feigning isolation to get food packages would have definitely done the same as a student!
https://www.cam.ac.uk/sites/www.cam.ac.uk/files/documents/pooled_testing_report_30nov-6dec.pdf
