This is part of a continuing series of recommendations put out by CoVaRR-Net. These recommendations are directed to the Federal Deputy Minister of Health, local and provincial medical health officers, the Urban Public Health Network, the Variant of Concern Expert Panel, and public health officials.
The current environment of the COVID-19 pandemic is very fluid. Some of these recommendations may soon be out of date.
Jurisdictions across Canada are employing rapid antigen tests (RATs) for asymptomatic screening, symptomatic diagnosis, and outbreak management. Research has reported on the effectiveness of employing RATs for outbreak management for large gatherings and events. Research data is also emerging on rapid antigen testing in settings such as schools, including the frequency of testing that would be needed for reducing outbreaks.
In high-risk settings for outbreaks (workplaces, care homes, schools, universities, prisons, and hospitals), repeated and frequent RATs cut delays in delivery of test results, providing a real-time tally of cases and close exposure contacts and, in turn, identifying clusters quickly and limiting spread.
Bringing RATs to rural locations was found to reduce COVID-19 transmission, as well as promote and implement local mitigation strategies, and improve contact tracing.
Despite having less sensitivity than the PCR tests, research has found that RATs have the potential to be impactful, at the level of unit cost per outcome, than current COVID-19 diagnosis tools.
Clinical and economic modelling found that testing nationwide on a weekly basis averts 2.8 million infections, 15,700 deaths, and increases costs by $22.3 billion compared to a no-testing scenario, which results in 11.6 million infections, 119,000 deaths, and $10.1 billion in costs over the course of 60 days.
The use of at-home RATs has implications for COVID-19 public health monitoring. Currently, Canada’s federal and provincial jurisdictions lack a database for recording RAT results.
At the federal level:
- Fund, develop, and build a database to record and disseminate Canada-wide data on provincial rapid antigen test (RAT) results.
- Fund and procure enough RATs so that Canadian jurisdictions can manage any possible outbreaks.
At the provincial and territorial levels:
- Implement workplace screening for RATs to be used when a facility is deemed a COVID-19 outbreak site. RATs can be employed as a screening tool for asymptomatic individuals in places where an outbreak has occurred.
- Recommend that a positive RAT test require an isolation time of seven days and/or a 48-hour symptom-free period (whichever is longer) for all populations, based on the generation time (i.e., exposure to resolution in a person) of Omicron.
- Develop a formal mechanism to connect at-home test results to provincial public health units. This would ensure that proper contact tracing and isolation protocols are followed and that a diagnosis is recorded for both monitoring and program applications.
At the local and regional levels:
RATs should be used to screen for large events and gatherings, with the additional use of masks, as well as the ensuring of optimal ventilation. Symptomatic individuals or individuals that have been exposed to a COVID-19 case should not attend even if the RAT is negative.