Oxford University’s testing service has confirmed a record-low of 21 cases of COVID-19 among students and staff for the week 21st-27th November, with a positivity rate of 15%. Following a drop from 126 to 40 confirmed cases, this marks a further reduction in weekly numbers by 50%.
This term started off with close to 200 new cases confirmed in each week, until new case numbers began falling in weeks 4 and 5. However, the number of tests conducted in these later weeks was down almost 50% compared to earlier this term, while the test positivity rate reached record highs. By week 5, the University’s testing service had recorded almost 1,000 cases of COVID-19 among students and staff (Oxford’s current student population is close to 24,000). Week 6 marked the first substantial drop in the positivity rate to 17.2%, down from its peak at 34% in week 4. New case numbers also dropped by 70% that week. This week continues a trend of rapidly dropping new case numbers, with several colleges recording no active cases at all.
This week, the University will provide Lateral Flow Immunoassay Tests (LFIA) to all students before they leave. In an email to students, the Vice Chancellor confirmed that “Colleagues across the collegiate University are working hard to ensure that we will be able to offer two lateral flow tests to all students in 8th week so that you can safely travel home for Christmas confident that you will not be endangering the health of your family and friends.” The test requires individuals to take a swab of their nose and throat and insert it into a tube of liquid for a short time, with a result provided after 20 to 30 minutes. They are aimed at potentially supplementing, rather than replacing, the standard use of RT-PCR (reference test polymerase chain reaction) tests.
Lateral Flow Tests have received criticism for not being sensitive enough to allow for a “test and release” strategy to allow students to go home from university. The ongoing assessment, carried out by Public Health England’s Porton Down laboratory and the University of Oxford, tested a number of lateral flow devices in different settings including hospitals, schools, and universities. The test’s sensitivity was reported at 58% when used by the public, with a false positive rate of 0.38%. This would mean that the tests may miss half of COVID-19 cases. However, the test’s sensitivity rose to over 95% in individuals with high viral loads, meaning that it will likely identify those who are most likely to go on to infect others. Jon Deeks, Professor of Biostatistics at the University of Birmingham, has noted that of 100,000 people being tested, Lateral Flow Tests, would, on average, find 630 positives – of which only 230 would actually have the virus, while 400 would be false positives.
Students who are travelling overseas may need to provide a negative Polymerase Chain Reaction (PCR) test result, which is more reliable than Lateral Flow Tests. Some colleges are offering standard RT-PCR home test kits, including Lady Margaret Hall and Green Templeton College, who are offering travel tests at a price of £115 to their students.
The University has implemented a four-stage emergency response, depending on how wide the spread of Covid-19 is. The current status is Stage 2, which allows the University to operate “in line with social distancing restrictions with as full a student cohort as possible on site”, with teaching and assessment taking place “with the optimum combination of in-person teaching and online learning”. A Stage 3 response would imply “no public access to the University or College buildings” and “gatherings for staff and students only permitted where essential for teaching and assessment to take place”.