The decision by provincial and territorial governments to scale back COVID-19 data collection and reporting has left Canadians to navigate what some experts are calling the most uncertain wave of the pandemic to date.
Most jurisdictions have stopped testing broadly and are now limiting or consolidating data, such as hospitalization indicators. Many have also reduced public reporting frequency from daily to weekly.
Governments that have done this – including British Columbia, Alberta, Saskatchewan and Manitoba – attribute the shift to there now being more value in observing trends over time, rather than daily fluctuations. But those who have worked to prepare Canadians for what may lie ahead say they are now flying blind as the last remaining public-health measures are lifted and the Omicron sub-variant BA.2 fuels a resurgence of cases.
“The absolute worst time to change your data streams is on the rise of a new variant, and that’s exactly where we are,” said Sally Otto, a professor at the University of B.C. and a member of the independent B.C. COVID-19 Modelling Group.
“I can’t make model predictions about how many hospitalizations are coming up because I don’t actually know how many people got infected in the first [Omicron] wave, and when, and how high their immunity is.
“I would argue that we have, really, no idea of whether or not we’re going to see the same hospitalizations as our first wave, or less. It could be substantially more and we’re going into this not knowing.”
Dr. Otto said the reason it could be substantially more is because the most vulnerable populations were protected by recent boosters during the first Omicron wave.
This past winter, the highly transmissible Omicron variant pushed COVID-19 cases to previously unseen peaks, prompting most provinces to limit the use of lab-based polymerase chain reaction (PCR) testing to those at highest risk. This had implications that extended beyond the tracking of how much COVID-19 is in the community.
The independent modelling group of which Dr. Otto is a member issued its 20th report on April 6. It called the BA.2-driven wave the “most uncertain point so far in the pandemic for modelling” because of scant data on the total number of recent infections and the extent of immunity heading into this latest wave.
Without adequate testing, the group of experts in epidemiology, mathematics and data analysis say they cannot study vaccine and booster effectiveness against infection, or hospitalization, by age. They also don’t have a good sense of susceptibility to reinfection, which relies on knowledge of past infection. As well, B.C.’s hospital admission data are updated irregularly across health authorities, leading to large swings in daily admission estimations.
“We cannot handle and mitigate risks that we don’t know are coming,” Dr. Otto said.
Her group would like to see a random sampling of the population be tested for COVID-19, either as part of a work force (such as health care workers), through a random census (such as by mailing out testing packages), or by testing those admitted to hospital for non-COVID reasons.
Peter Juni, the outgoing scientific director of Ontario’s independent COVID-19 Science Advisory Table, similarly said there needs to be a pragmatic approach to continue testing for disease surveillance.
“We need to replace the widespread clinical testing with something that is affordable and gives us the necessary information, and that’s a random sampling of people,” he said.
Dr. Juni said wastewater surveillance has been an important tool in helping Ontario navigate the Omicron waves. An analysis of wastewater signals from treatment plants showed that the province likely had between 110,000 and 140,000 infections a day during the first Omicron wave over the winter, he said. The current BA.2 wave reached between 100,000 and 120,000 infections a day, and provisional estimates released this week indicate infections may have crested.
However, Dr. Juni noted that there is still considerable uncertainty, attributed to factors such as waning vaccine immunity, weather change and how people chose to behave in terms of lifted public-health restrictions. He added that there is also an increasing amount of infection-acquired immunity, but it’s impossible to determine how much.
“To give you a hunch, Ontario, with 14.7 million people, we could be anywhere between roughly 4.5 and six million infections that have happened since Dec. 1,” Dr. Juni said. “That’s a big difference.”
The Centre for Health Informatics at the University of Calgary maintains a wastewater dashboard for Alberta, while B.C.’s wastewater surveillance is limited to five treatment plants in Metro Vancouver. The University of Saskatchewan tracks wastewater from treatment plants in Saskatoon, Prince Albert and North Battleford.
Canada’s Chief Public Health Officer has acknowledged the impact of reduced PCR testing.
“PCR continues to be important,” Theresa Tam said at a federal briefing on Tuesday. “Even with a drop in testing, and because it’s more targeted toward the higher risk population, we do need to have more representative testing wherever possible. So I think that should continue to be encouraged.”
Michael Wolfson, former assistant chief statistician at Statistics Canada and a current member of the University of Ottawa’s Centre for Health Law, Policy and Ethics, said Canada’s data collection infrastructure is inadequate and raises “questions of accountability all up and down the line.”
He noted that while provinces and territories administer and deliver health care in Canada, providing statistics is a federal responsibility. He said Canada would have benefited from a national, integrated COVID-19 monitoring health-information system with standardized data, and blamed “provincial obstinacy” and constitutional conflict over jurisdiction as barriers.
“Health data is not health care,” Dr. Wolfson said. “It snuggles up closely, and is closely linked, to health care, but to the extent you think of it as statistics, it’s federal jurisdiction. So the federal government, in my view, should be willing to say to the provinces, ‘Sorry guys, you want another $20-billion a year to bring the federal contribution up? If you don’t ante up, you know, collaborate and work together on getting decent data, we’re not going to give you all that money.’”
Kerry Bowman, a professor of bioethics and global health at the University of Toronto, said there are “certainly” concerns with the reduction in COVID-19 data being made available.
“Good ethics is based on good science, and good science is based on good data, and we don’t have any of that,” Dr. Bowman said. “When you turn to people and say, ‘You now have to take individual responsibility, not just for yourself, but for the vulnerable people in your life …’ you cannot expect people to make good decisions without data.”
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