Should we be testing students that don’t have symptoms?

As the debate in the UK rages on about testing – and specifically whether we should have been and should in the future be testing some (or all) students without symptoms – a new revision to the CDC advice is a fascinating intervention into that debate.

Big thanks to Benjy Renton and Mike Otsuka for altering me to this.

Back in June, the CDC was unequivocal:

Testing of all students, faculty and staff for Covid-19 before allowing campus entry (entry testing) has not been systematically studied. It is unknown if entry testing in IHEs provides any additional reduction in person-to-person transmission of the virus beyond what would be expected with implementation of other infection preventive measures (e.g., social distancing, cloth face covering, hand washing, enhanced cleaning and disinfection).

Therefore, CDC does not recommend entry testing of all returning students, faculty, and staff.

You’ll see it didn’t go quite as far as some have with the “ah but it breeds complacency” line, but it wasn’t far off.

But things have changed. Last week JAMA (which publishes research and commentary on clinical care, health policy, and global health) published a commentary on university campus reopening in the US. Trouble is, it’s all a bit horse bolted/stable door:

In a college or university setting, with frequent movement of faculty, staff, and students between the college and the community, a strategy of entry screening combined with regular serial testing might prevent or reduce transmission of SARS-CoV-2.

CDC was always advising testing those with symptoms or those with a recent known or suspected exposure to someone infected – which, remember, goes further than we do right now given the advice is that if you live with someone who has coronavirus but you do not have symptoms yourself you need to self-isolate, not get a test.

But now – probably as a result of the JAMA piece – CDC goes further with some additional examples of when testing might be performed:

• Are part of a cohort for whom testing is recommended (in the context of an outbreak)
• Are attending an IHE [ie university] that requires entry screening (entry testing as part of screening)
• Are in a community where public health officials are recommending expanded testing on a voluntary basis including testing of a sample of asymptomatic individuals, especially in areas of moderate to high community transmission (screening)
• Volunteer to be tested in order to monitor occurrence of cases and positivity rate (surveillance)

This issue – of testing asymptomatic individuals – is expanded on later:

Areas of campus where students might be crowded together (e.g., residence halls or other congregate living spaces, dining halls, locker rooms, laboratory facilities, libraries, student centers, and lecture rooms) may be settings with the potential for rapid and broad spread of SARS-CoV-2.

As a result:

Diagnostic tests may be appropriate in areas of high community spread, at the discretion of the ordering provider. If necessary, broader testing beyond close contacts may be done simultaneously with other strategies to control transmission of SARS-CoV-2 on campus. This can include expanded or widespread testing.

These two concepts (expanded and widespread testing) are then explained. Expanded includes testing close contacts of people with Covid because testing in these situations “can be helpful as in high density settings it can be particularly challenging to accurately identify everyone who had close contact with an individual confirmed to have Covid-19”, like, you know, in a traditional halls of residence.

Widespread testing includes testing of individuals who have been potentially exposed at some point and might include testing across campus building(s). It may also be considered based on the preliminary results from initial, targeted, or expanded testing or repeat periodic campus testing such as testing across residence halls:

Widespread testing may also take into consideration local institutional factors like capacity and availability of testing locally, mitigation strategies, current academic instruction plan (percentage of classes meeting in person), status of residence halls (open or closed, students per room), access to dining halls and recreation areas, access to laboratory facilities, status of sports facilities like weight rooms (are they open or closed), status of other extracurricular activities related to campus including those with large gatherings or congregate living spaces (e.g., communities of faith, sororities, fraternities) and occurrence of athletic events with spectators and other mass gatherings.

There’s also a proposed tiered approach for testing of people with possible exposure in the context of an outbreak, entry screening (which is likely now to become interesting in January), and a whole section on off-campus testing:

Off-campus community settings including apartments, bars and restaurants, and community spaces related to campus (e.g., spaces for athletic events, mass gatherings of communities of faith, sorority and fraternity organizations, or other groups) might pose a higher risk of SARS-CoV-2 transmission than classroom settings if social distancing policies and mitigation procedures are not being followed.

Strategies to mitigate the spread of SARS-CoV-2 are not only to limit transmission on IHE campuses, but to also prevent transmission to the surrounding community. IHEs should communicate frequently to students, faculty, and staff about the risks in these settings and the potential impact on the IHE’s ability to function. The communication methods should be accessible for all, including those with disabilities and limited English proficiency (e.g., through interpreters and translated materials).

At the time of writing we are still waiting on guidance from the government on students “returning home” at Christmas. But soon enough we’ll need to be thinking about reviewing whether the strategies this term worked and – if we are going to persist with the “great migration” part 2 in January – how to handle it. If the new CDC recommendations get implemented, with their focus on targeted testing of the asymptomatic – we’ll need to sort out whose responsibility that is between PHE and universities fast.