PoP BC Briefing #3- Testing Strategies for Success

Want to keep track of our work? Sign up for PoP BC updates, actions, public health information, and announcements.

Nov 3, 2021: Testing Strategies for Success

How can COVID-19 testing be used as a strategy to end the pandemic? What is the difference between rapid tests and PCR tests? How are rapid tests useful, and how are they used in other jurisdictions to allow people to congregate safely? And what is BC’s testing situation, and what can be done better so BC can drive COVID-19 transmission down so we can participate in our daily lives safely, while also protecting the health care system?

Facilitator: Melody Ma, Community Rapid Testing advocate, UBC Medical Laboratory Science


  • Dr. Victor Leung, Infectious Disease physician and medical microbiologist specializing in infection prevention and control and antimicrobial stewardship
  • Dr. Paul Tupper, Professor, Department of Mathematics, SFU. Member of the BC COVID-19 Modelling Group
  • Dr. Lisa Barrett, MD, PhD Clinician Investigator and Infectious Disease specialist, Dalhousie University, Department of Medicine. Pioneer of rapid testing programs in the community in Nova Scotia
Get the slide deck

Highlights from this briefing

Dr. Leung reveals the drawbacks of relying exclusively on PCR testing for detecting cases that lead to community spread.
Dr. Tupper talks about the usefulness of Rapid Antigen Testing (RAT) in the containment of school-based outbreaks of COVID-19.
Dr. Barrett discusses how rapid antigen testing has been used effectively as a tool of community engagement in Nova Scotia.
Dr. Leung discusses the issues with relying on PCR testing, which is most effective after the most infectious period of COVID transmission.
Dr. Leung points out that in every aspect other than the narrow metric of test sensitivity of an individual test, rapid antigen tests perform better than PCR tests.
BC is not using all the tools provided by the federal government to detect cases before they lead to community transmission. Dr. Barrett responds.

Summary of Key Points

  • There are different types of COVID tests, which answer different questions.
  • Tests can help protect people in many ways.
  • Rapid tests should be widely available in BC, as they are in Nova Scotia

What are the different types of tests?

PCR vs Rapid testing comparison

PCR or RT-PCR (Reverse Transcriptase -Polymerase Chain Reaction) detects small pieces of the virus, even after the infectious period is over. This is the lab test.

PCR tests answer the question, Does this person have COVID? It is the gold standard to diagnose a person with COVID. The test is conducted with a deep nose swab or a saliva sample. In a hospital setting, it can take hours to get results. At testing sites, the results can several days. A PCR test can be positive long after a person is no longer contagious.  

It can be hard to access these tests as many BC testing sites have been closed.  In many areas you must now schedule a test. Travelling to the test exposes others to COVID since you may be spreading it to others while you wait for your result. The extra pressure of isolation while waiting for results is a huge burden.

RAT (Rapid Antigen Testing) requires a significant amount of the virus to be present, unlike the PCR test, which can detect even small amounts of virus RNA.

This test answers the question, is this person infectious with COVID?  This is a shallow nose swab, and can be done anywhere since no lab is required.  Results are ready in 15 minutes. It can detect the virus before symptoms start, and also in the peak infectious stage. 

You can isolate immediately if you find you have COVID and you don’t interact with others while travelling to or getting tested. False negative tests happen. You can repeat the test in a day or two or get a PCR test if you still have symptoms and a negative RAT test. False positive tests are rare.

How can BC make better use of testing?

The infectious period of COVID precedes the onset of COVID symptoms

More than half of COVID transmissions happen before a COVID+ person has symptoms.  Rapid tests can detect COVID before people feel sick.

If staff at acute care hospitals and long term care homes were regularly screened with rapid testing, we could reduce outbreaks in these facilities. Dr. Tupper reports that rapid testing in long term care homes could prevent 50% of the infections brought in by staff. 

Rapid testing is also useful at homeless shelters and other places where people live or work close together to help reduce community spread. 

In schools, we could rapid test children who were exposed to a student with Covid-19 to determine whether or not they should stay in school.  Regular testing of whole classrooms is conducted in Germany. RATs detect exposure as early as possible.

People could use rapid tests to self-screen before visiting grandparents, families with a new baby, or others who are at higher risk if they become infected.  

Engaged Communities is a BC non-profit organization that delivers tests to be used at home in COVID hot spots, in partnership with Fraser Health Authority.

Are other provinces using rapid testing more effectively than BC?

Dr. Lisa Barrett shares her experience in Nova Scotia as a champion for the community use of Rapid Antigen Tests. The effort has involved thousands of people, the government, Public Health, the Nova Scotia Health Authority, and many community members. During the third wave, widespread use of community RAT by trained community members detected 20% of early cases, allowing the wave to peak and come down early.  Community members organized and offered asymptomatic rapid testing wherever there was community spread.

Since the spring of 2021, rapid testing has been used in vulnerable sectors like shelters, public housing, and more recently, universities and schools.  In rural areas that are far from a PCR testing site, RATs can be used with symptomatic children to avoid travelling for days, requiring parents to take time off from work. If the test is positive, it should be confirmed by PCR.

Nova Scotia is also distributing thousands of repackaged individual Pan Bio rapid tests, allowing people to test at home and self-regulate their reporting. The province has a low threshold, low barrier testing system. No appointment is needed to get a PCR test anywhere that RATs are distributed or administered.  Dr. Barrett recommends that other provinces such as BC start using RATs.

“Just do it, limit less, empower more. Let people lead in the community. It will pay off in building trust, engagement and involvement.”

Why should we use more rapid testing in BC?

Vaccines alone are not enough to end the pandemic. Testing helps us get together safely, and helps keep COVID out of our workplaces and schools. Testing helps us detect who is infectious and isolate them quickly in order to break chains of transmission. Testing also helps us know who has COVID 19 so we can track its long-term effects and learn more about this new disease.

Rapid Antigen Testing is an effective Public Health tool.  We have free tests provided by the Federal Government. We need better access to this important layer of protection.

Addendum, December 2021:

RAT can be used with the Omicron variant, but because of the virus’s rapid doubling time, testing should be performed as close in time to an in person meeting as possible. To increase detection of COVID antigen and improve the test sensitivity, experts in the UK, which has extensive experience with RATs, recommend swabbing both the throat and the nose. Use the same swab to sample first the throat and then the nose.

Share this:

Archived Briefings from Protect Our Province BC

Map of Canada with provinces colour coded from green to red based on ease of access to Paxlovid. BC is red.
Date: Wednesday, March 1 2023 at 2:00 PM PST A conversation with Protect Our Province BC doctors about Paxlovid and access to this useful Covid medication in BC Join Dr. Susan Kuo and Dr. Lyne Filiatrault of Protect Our Province BC on Wednesday, March 1, 2023, 2 pm, for a conversation about Paxlovid.  BC is… Continue reading Mar 1, 2023: Paxlovid: Why Should You Care?
Image of Dr. Gandhi on a blue background with the PoP BC logo and text that reads:
Date: Friday, Feb 3, 2023 at 1:30 PM PST Ever get the feeling we’re not getting the real story about COVID?Apparently “the pandemic is over!” yet it seems like everyone you know is ill or has a family member who is, while schools have multiple classes merged together because of so many teachers are out… Continue reading Feb 3, 2023: COVID Reality Check with Dr. Sanjiv Gandhi
Title image for briefing May 16, 2022 - COVID-19: I wish I had known...
Date: Wednesday, May 16 at 12:00 noon PDT What is it that people need to know about COVID-19 that they don’t know already? What about people who are tired of hearing about it? There is a lot that isn’t being communicated well to the general public, especially about long-term effects of the virus. Those who… Continue reading May 16, 2022: COVID-19: “I Wish I’d Known… “

More News from Protect Our Province BC

A view of 4 children from the waist down, standing in a row facing the camera. They are wearing rubber boots and the child second from the left's hands are visible - they look like they are held in fists. Text at top is
Dr. Rae Duncan, UK Cardiologist and Long Covid researcher, shares her thoughts on how schoolchildren are not being adequately protected from COVID-19 infections and their health impact.
Header image for the Sickest Children by Dr. Susan Kuo, featuring the Doctor, a painting by Luke Fildes, 1891.
Being a family physician is always challenging. It has become even more challenging during the ongoing COVID pandemic, which is now compounded by a seasonal flu epidemic and the multiple other viruses circulating in our community. Here is a glimpse of what my days in the office have been like recently.
Image of a senior in a wheelchair being pushed by a carer in an open field, heading says
Share This “A true measure of any society can be found in how it treats its most vulnerable members.”Mahatma Ghandi At the September 28th BC Covid update, BC Health Minister Adrian Dix announced that in order to increase the in-hospital capacity with 1500 surge beds for impending COVID and influenza cases, patients would be “decanted”… Continue reading The Most Vulnerable People in B.C.