As COVID-19 infections in Ontario hit record levels Thursday, some health experts say the actual number of new cases is likely much higher than reported, raising concerns about the development of a local variant. .
Ontario hit a record 5,790 reported cases Thursday and Toronto followed suit with its highest daily count of 2,309, but experts say these numbers no longer tell the full story.
They say the actual number of infections has likely become unknowable and far beyond what is reported in daily case counts.
The province’s PCR laboratory testing network, which is how case counts are reported, is strained and cannot test everyone who may have the virus.
“What we’re seeing is just the surface,” said Dr. Saverio Stranges, chair of the department of epidemiology and biostatistics at Western University. “Many public health scientists, in many countries, are suggesting that we really should focus on hospitalizations now.”
In Toronto, daily hospitalizations have decreased. Last week’s average was 2.7, down from 4.6 the previous week. The peak of the pandemic was 93 in April.
But Stranges cautioned that focusing only on hospitalizations could create a false sense of security.
Most of the population is vaccinated and therefore unlikely to be hospitalized if they contract Omicron. But a small, though significant, part is still extremely vulnerable to the worst of the virus. Case counts give an idea of your relative risk when coming into contact with other people. If ignored, they could end up in more danger than they think.
“A segment of the population, the most frail, people with comorbidities, the elderly, have serious ramifications of the infection,” Stranges said. “It is compensation. We can’t trust the case counts that much, but we have yet to analyze them to inform our public health policies. “
Toronto’s chief of public health, Dr. Eileen de Villa, said the city’s seven-day average of hospitalizations had dropped, but there has been a slow increase in recent days “that will take a little longer to reflect. in those seven daily moving average, “he said. “I think you’ll see it start to climb.”
In an interview Thursday, De Villa said there is still “careful conversation and observation and monitoring” of all COVID-19 metrics, including case counts.
“The case counts are still being looked at, but more and more we are looking at things like hospitalizations, ICU, percentage of positivity and reproductive numbers,” de Villa said. “Based on what we are seeing, we will make recommendations (to the province) on what the evidence suggests would help us.”
The more people who become infected with the virus, the more opportunities it has to mutate, said Omar Khan, an expert in molecular engineering at the University of Texas.
The high case counts are “directly related to viral evolution,” he said. “If we increase the number of replications, we always increase the probabilities of mutations and the evolution of a new variant.
“This rapid evolution is what led us to Omicron, Delta, Beta and Alpha.”
Khan pointed to children ages 5 to 11 as an example of a population that is not yet fully protected.
“There are a lot of people who are actually partially vaccinated, not because they are anti-vaccines, but simply because they literally couldn’t get it,” Khan said.
De Villa said concerns about the development of another variant is one of the main reasons Toronto is asking residents to limit contacts.
“The more transmission there is, the more opportunities there will be for the creation of a new variant; that has always been a new concern, ”he said. “It could be here or in the United States or in Western Europe, where they are also experiencing rapid growth.”
The evolution of the virus makes it difficult for our current tests to detect variants, Khan said.
“Evolution, if the virus continues to change enough, our diagnostic tools need to be updated and it takes time to develop new ones,” he said.
Another risk indicator is the test positivity rate – the number of PCR tests per day that are positive. On Thursday, the positivity of tests in the province reached a staggering 16 percent.
“In Europe, it has been between four and five percent,” Stranges said. “It’s likely to be even higher here, because we are likely missing a lot of cases.”
Stranges said that if the positivity rate stays that high or grows, Ontario may need to implement stricter public health measures.
“It will also come down to the capacity of the hospital, which always drives political decisions,” he said. “And the potential impact of the virus on essential workers. That’s certainly a concern, and that concern could prompt stricter measures. “
Asked Tuesday if people should still focus on the case count, Ontario’s chief of public health Dr. Kieran Moore said the province will begin to increasingly focus on ICU hospitalizations and admissions. , with the knowledge that it is being tested and without capturing everything exponential. case of growth happening.
Ontario is looking at when, or if, Omicron begins to affect hospitalization and ICU rates “as a sign that we will have to take possible additional precautions.”