Experts say Canada needs to develop a robust system for detecting COVID-19 activity in the absence of large-scale PCR testing.
Since the beginning of the Omicron option, provinces and territories have reduced access to gold-standard PCR testing, citing a lack of capacity to sustain demand and the need to free up health resources.
Since then, many people have relied on the results of rapid antigen tests, but they are less reliable in detecting the Omicron variant or reporting and tracking the way PCR tests are. Experts say there needs to be a better way to inform people about COVID-19 activity in their communities.
Dr Caroline Colleen, a mathematician and epidemiologist at Simon Fraser University, said there were currently “too many infections” in Canada to increase access to PCR tests for everyone to understand the true number of infections.
She said more stable programs could also be used to catch other types of respiratory infections.
“And I suspect they are under development, but until they are developed, deployed and the results are publicly available, people will have trouble understanding the risks in their social group, in their community and in the workplace,” he said. she. .
“So then they will have problems with the information they need to inform their own choices, their own jobs or community policies.
Colleen said wastewater data is a really important source of information that can be shared publicly without compromising anyone’s personal medical information and can help communities understand the spread of COVID-19. But like PCR and rapid tests, she said it has its limitations.
She noted that there are many factors that can change wastewater signals, such as precipitation, temperature and different variants, leaving different amounts of consistency in the water, leading to less accurate estimates of COVID-19 cases.
Colleen said he expects an integrated system that will include wastewater data, along with PCR and rapid test results, in a way designed to paint a more accurate picture of how many COVID-19s there are in the population and to inform people for the risk of infection. the virus.
“So we need to think about how to get representative samples and how to find out how many infections there are,” she said.
Dr Dan Gregson, an infectious disease physician and medical microbiologist at the University of Calgary, said it would be wise to expand access to PCR testing to certain locations, such as schools and long-term care homes in the event of an epidemic, so that decide whether to close these institutions in order to prevent further handover.
However, he said the average person can rely on wastewater data to assess the risk of COVID-19 contamination in their community, as it is “much more cost-effective” and “tells us such information” on PCR testing. .
Dr Peter Juni, scientific director of the COVID-19 Scientific Advisory Table in Ontario, said it was “probably not sustainable” to re-expand access to PCR testing for all symptomatic individuals due to the high cost of the tests.
Juni noted that when PCR testing was available to all Ontario residents, only somewhere between 30 and 45 percent of infections were detected because not everyone was tested for the virus. Some may have been asymptomatic, while others may not have had time to be tested, and others may not have been tested early enough.
As for the rapid antigen tests available in Canada, he said they had shown “lower test effectiveness” when it came to detecting the Omicron variant.
We need a COVID-19 detection system that can use a random sample of population to try to figure out what’s really going on, and that can be augmented if necessary, Junie said.
“If we see in wastewater, for example, that infections are starting to increase, (then) we can actually activate the system or expand it a bit, but it will just be a monitoring system that gives us enough situational awareness.
This report by The Canadian Press was first published on April 21, 2022.
———
This story was created with the financial support of the Meta and Canadian Press News Fellowship.
___
What questions do you have about Omicron?
With the advent of a new COVID-19 concern called Omicron, CTVNews.ca wants to hear Canadians with all kinds of questions.
Tell us what you would like to know when it comes to the Omicron COVID-19 variant.
To send your question, send us an email to dotcom@bellmedia.ca with your name, location and question. Your comments can be used in the history of CTVNews.ca.
Add Comment