Making the Case for Asymptomatic Testing

We’ve all been through COVID-19 screening protocols, maybe at a restaurant, your workplace, or when you enter a salon to get your much anticipated post-lockdown haircut. The usual process involves answering questions about your symptoms and maybe even a temperature check.  Unfortunately, research suggests that 30-50% of all SARS-CoV-2 infections are transmitted by people who do not show any symptoms [1]. These individuals are either “pre-symptomatic”, meaning they are infected with the virus but have not yet developed symptoms but will develop them later, or “asymptomatic”, which means while they are infected with the virus, they will never develop obvious symptoms.    

These asymptomatic and pre-symptomatic cases play a role in the transmission of the virus in our communities and thus pose a significant challenge to infection control.  Identifying infected individuals while they are pre-symptomatic and asymptomatic will play a major role in stopping the pandemic.  An example of this concept is a 53-year-old UK patient who had COVID-19 but was asymptomatic and unknowingly caused up to 11 other infections [2]. Asymptomatic testing in this scenario could have allowed the infection to be identified earlier and prevent further spread.  

The reason behind asymptomatic infection spread, even though the infected person isn’t coughing or sneezing, is that the SARS-CoV-2 virus uses the upper respiratory tract to reproduce. Therefore, normal exhalations, heavier breathing, shouting, and even laughing can spread tiny droplets of mucus that can infect others.  

Many Canadian provinces are now lifting pandemic restrictions, including wearing masks in some public spaces, increasing the limits on the number of people allowed to gather indoors, and re-opening borders to international travellers. This increases the potential for asymptomatic cases to spread the virus, especially to vulnerable and unvaccinated populations.   

While vaccination rates are on the rise in Canada, unvaccinated cases accounted for 95.4% of COVID-19 cases from December 14, 2020, to July 24, 2021, in Ontario [3]. Only a small portion of the global population received at least one dose of a COVID-19 vaccine (33%), this could mean that those who are unvaccinated, who may be infected but asymptomatic, can spread the virus further through domestic and international travel. This becomes especially problematic with the lifting of certain restrictions, such as wearing masks. It is important to keep testing, especially for those who are unvaccinated, as they may be asymptomatic or pre-symptomatic. 

Testing, in general, is an important step in managing this pandemic. Experts agree on the fact that there is an urgent need to go back to previous levels of testing if we want to have a better view of the spread of the virus and identify current and potential variants [4]. This includes testing of asymptomatic populations as these infections have the same transmissibility rate as symptomatic infections [5].  

Through testing, it is possible to:
  • Mitigate the spread of the virus and prevent large outbreaks
  • Help contain an outbreak if it does occur  
  • Protect vulnerable communities and populations
  • Support the safe re-opening of our economy 

The bottom line is that testing can save lives and can help us return to a more normal way of life. At PBI, we are working hard to bring organizations and communities testing solutions to keep their members, workforce, and clients safe.

We are proud to offer the Sofia SARS Antigen FIA test, which is the only antigen test approved for asymptomatic testing by Health Canada. While regional guidelines may allow you to use an antigen test without asymptomatic testing approval from Health Canada, only the Sofia SARS Antigen FIA test is specifically approved for asymptomatic testing, providing you peace of mind that the test you are using is designed to detect COVID-19 in people who are not displaying obvious symptoms.  

Contact us to find out more about our testing solutions and how they can help you achieve your goals in keeping your work environment safe and contribute to the effort to eradicate COVID-19. 


[1] A systematic review of asymptomatic infections with COVID-19, Zhiru Gao, 1 Yinghui Xu, 1 Chao Sun, 1 Xu Wang, Ye Guo, Shi Qiu, and Kewei Ma, J Microbiol Immunol Infect. 2021 Feb; 54(1): 12–16. 

[2] Gulland A. 2020. Could you be a coronavirus super spreader? Http://

[3] Confirmed Cases of COVID-19 Following Vaccination in Ontario: December 14, 2020 to July 24, 2021, Public Health Ontario, July 2021.

[4] How falling levels of COVID-19 tests could threaten pandemic fight – ABC News (

[5] Chen Y., Wang A.H., Yi B., Ding K.Q., Wang H.B., Wang J.M. The epidemiological characteristics of infection in close contacts of COVID-19 in Ningbo city[J/OL] Chin J Epidemiol. 2020:41. doi: 10.3760/cma.j.cn112338-20200304-00251.

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Founded in 2016, Precision Biomonitoring provides industry-leading expertise in molecular direction of organisms. Their very own TripleLock™ technology aims to deliver rapid, on-site environmental, food, animal and human diagnostic testing solutions. Customers are any organizations that need onsite surveillance and rapid identification of any organism in any environment. The Precision Biomonitoring team is at the forefront of technological innovations in the genomics industry. Our vision is a world where we can identify any organism on the spot, in an instant, anywhere on the planet.