The general population

Single event

Here we define a ‘single event’ as an event that will not be routinely repeated with the same group of individuals (e.g. accessing an airport for travel, visiting a restaurant, or visiting a stadium as a spectator). This category encompasses a broad range of scenarios and recommendations will need to be specific for each setting.

Single event current practices

There is no standardized approach to testing within the community, both NAATs and antigen tests are being used. As an example scenario, many airlines and airports are developing pre-flight testing requirements, and currently these have not been regulated by the international community or even by local governments.81
When considering the appropriate test, if individuals can isolate between their test and the access event, then centralized NAATs could be used to deliver high volumes (e.g. people accessing an airport or a stadium event). In this asymptomatic population, pooling samples could be useful in order to maximize the testing capacity, although this may reduce the sensitivity of tests and, as such, is most appropriate for use with centralized PCR testing as the most sensitive method of detection.44,47-49,82 However, this would not be practical for activities such as visiting a shopping center or restaurant. Highly sensitive antigen or NAAT point-of-care tests could be performed by non-laboratory trained personnel in these settings; however, whilst these tests provide quick results (10–15 minutes), they may not be suitable to conduct in crowded environments. Lateral flow antigen tests could be a simple and cost-effective way to test large groups of people; however, studies report high numbers of false-negative and false-positive results, meaning COVID-19 precautions should still be employed.28,83,84

Single event key considerations

When considering testing of the general asymptomatic population for access to single events, the key considerations should include:

Repeat access

Repeat access settings comprise workplaces, universities, schools, and hospitals, where the same group of people repeatedly interact together.

Repeat access current practices

Testing in repeat access settings is already being widely conducted, for example, many hospitals are regularly testing their healthcare staff using NAATs.85 In healthcare staff, regular testing is leading to the identification of many COVID-19 cases, enabling prompt isolation and therefore limiting outbreaks within hospitals.86 In healthcare settings, testing staff has clear benefits for the costs involved with screening: the prevention of COVID-19 outbreaks among hospital staff, subsequent staff absences, and nosocomial transmission to potentially vulnerable patients. Pooling samples can also help to make screening these populations more resource efficient.44,82
Professional athletes and their support staff around the world have been subject to regular testing so that sports can continue during the pandemic. This is often supported by isolation, social distancing, personal protective equipment for staff, and other measures to prevent infection.87-89 In these professional settings, the funding is often available to test regularly to ensure that the sports continue to operate, and these decisions sit with the sporting leagues and national governments.
For schools and universities, NAATs may not be needed, as antigen testing or LAMP may be sufficient to detect the most infectious cases. In addition, older students may be able to adhere to some social distancing and mask wearing measures. Overall, transmission has been noted to be lower in younger pupils compared with older pupils.90,91 Whilst the cost–benefit of NAATs for screening in school students would likely prove inappropriate, antigen testing may be suitable. Pooling NAAT samples could also help to manage NAAT testing volumes; however, this should be approached cautiously as methods are not standardized and pooling techniques are not automated, which does compromise efficiency.44
In these repeat access settings, a single infection could become an outbreak. Importantly, local prevalence of infection and necessity of the contact should be carefully considered before allowing any gathering of individuals.

Repeat access key considerations

Similarly to single access events, the prevalence of infection is an important consideration when sampling is being carried out, as well as the frequency of testing. In Germany, healthcare workers are currently tested on a weekly basis using a NAAT; however, testing frequency will need to be determined on the basis of each situation, the risk of infection, and the cost–benefit.