Observing rules will prevent COVID surge, models predict
Widespread physical distancing, the use of masks and good hygiene in May and June will prevent a surge of new COVID-19 cases in July and August, newly released models suggest.
The models, released Thursday by the Institut national de santé publique du Québec (INSPQ), show that if all Montrealers embrace infection control measures recommended by public health officials, few people will die of COVID -19 in the city this summer.
But if large gatherings take place, or if public health guidelines are ignored, infections will increase by the thousands, more people will end up in the hospital, and by July and August hundreds could die in Montreal each day.
The models must be taken with a grain of salt, according to researchers who worked on them. They are based on available data and can help paint a picture of what is to come, but they are not a crystal ball, says Marc Brisson, a researcher in the field of infectious disease epidemiology at Université Laval who oversaw the production of Thursday’s data.
“(Models) give us a good idea of the tendency if everything stays stable,” he said. “In reality, everything won’t stay stable.”
Brisson and Dr. Gaston De Serres, a medical epidemiologist at the INSPQ, presented the modelling via a remote news conference. They both hesitated to place exact numbers on what a worstcase scenario could look like in the summer.
What is clear from the models, they insisted, is one simple fact: if Quebecers adhere to public health guidelines, the rate of infection will slow. If they fail to do so, the rate will increase, perhaps catastrophically.
In the PRE-COVID -19 world, data suggested the average Quebecer came into contact with an average of 12.2 people each day, including their family, friends, co-workers and a few random interactions with people on their way to work. In confinement — the type of intense shutdown Quebecers saw in April — that number dropped to 4.5, and COVID-19 infections in the community dropped along with it.
The key to keeping infection rates low as society begins to reopen, the researchers said, is that people limit or eliminate their daily contacts where transmission is possible.
That doesn’t mean going back into confinement, but rather embracing a new reality, Brisson said. If interactions with friends and co-workers take place at a distance, or with proper protective measures in place, there is little chance to spread the virus.
“At the end of the day,” De Serres said, “it means that you have a capacity to transmit (the virus) with these new individuals you’re in contact with ... and if everybody was strictly respecting all these measures, then obviously there would be very little room for the virus to transmit from one to the other.”
The INSPQ models showed that outside of Montreal the spread of the virus was likely to be slow, but the models did not take into account inter-regional travel, which could increase transmission, the researchers noted.
Earlier this month the institute released models showing the expected impacts of de-confinement. The numbers showed that if Montreal businesses opened and people began to gather, the number of deaths and hospitalizations in the city would likely continue to increase.
Three weeks have passed since those predictions were released. COVID-19 hospitalizations are slowly declining and the daily number of new cases is shrinking modestly. Though there are still 1,331 COVID patients in hospitals, the number has gone down by 173 over the past week. Premier François Legault hailed the decrease in the number of patients as “very good news” at a Quebec City press conference on Thursday.
The early May models were off, or at least overly pessimistic, because they failed to account for changes in Montreal’s de-confinement schedule, Brisson said. The date for businesses to reopen in the greater Montreal area was pushed back one week, and officials cancelled the opening of schools in the area, fearing increased community spread.
Data showed daily COVID-19 infections and deaths reached a plateau in Quebec in April, Brisson said. The situation is now improving, but it remains a delicate balance, the researchers warned.
Dr. Horacio Arruda, Quebec’s public health director, said Montreal hospitals are still in danger of overcrowding, but the cost of confinement had begun to outweigh the benefits.
“It’s clear that we had the criteria to go opening,” he said, adding that the public now has a responsibility to slow the spread of the virus.
“The way people will respect the conditions of distancing, using masks and hygiene ... could have a tremendous impact on the local transmission.”
If everybody was strictly respecting all these measures, then obviously there would be very little room for the virus to transmit.