More information needed on second Omicron wave in BC, say independent modellers

The next Omicron wave is already upon us, says a group of independent scientists charting the COVID-19 pandemic in BC—but this one will be much harder to track, thanks to changes in how the provincial government releases COVID-19 data.

The province moved away from daily COVID reports on cases, hospitalizations, and deaths for the first time in more than two years last week, shifting instead to a weekly reporting system.

And while a member of the BC COVID-19 Modelling Group agrees the new system will make things harder to analyze trends and predict future developments, it’s not altogether surprising.

Data scientist Jens von Bergmann told the Beacon that even in the past few months, the province made a lot of changes as to how they reported data.

Stifled access to PCR testing near the beginning of the first Omicron wave in December, for instance, meant that reported case numbers were not at all indicative of the actual prevalence of the virus in the community.

“So in that sense, the changes aren’t that big, just because if we’re looking at cases, they weren’t really indicative of what was going on anyway,” von Bergmann said.

“If we’re looking at hospitalizations, all the data that we had was super noisy to start with. So that was hard too. We never really had good alternative data sources coming in. And that’s not changing either.”

What is changing significantly, however, is the timeliness of the data released to the public, along with many definitions of important metrics.

While reports will be released on a weekly basis every Thursday going forward, there will be a delay of several days in compiling them—which means that the report released this Thursday (April 14) will contain data from the Saturday-Sunday prior (April 3-10).

As well, the province has changed its definition of COVID-related death to include anyone who had a positive PCR test in the 30 days preceding their death.

The first weekly BCCDC report says the reason for switching to all-cause mortality reporting is that usually, it takes 8 weeks for a cause of death to be recorded.

Von Bergmann said the new metric will likely count some deaths that shouldn’t be included. The BCCDC plans to conduct retroactive evaluations of each case in order to evaluate true mortality levels–meaning numbers could change later on.

But other deaths that should be counted may not make it to the list, with PCR testing still difficult to access for the general population.

While many of the people who die of COVID are likely in hospitals or nursing homes, where they will be tested if they have symptoms, there could be some people who die at their own homes in the community without ever getting a PCR test.

While that in itself poses an issue for understanding the true number of lives lost to COVID, von Bergmann said it also makes it difficult to compare the information we had previously to the information we’ll be getting from now on.

“What’s really important is to have a consistent definition of things over time, because that’s how we can see how things change. And, of course, all the past information goes into the modeling. And one really disappointing part about the change is that these new metrics that we’re getting aren’t gonna get backdated,” he said.

“… So basically, what that means is that—we’re looking at the old definition of deaths, we’re looking at the new definition of deaths. But with the new definitions, we can’t really compare anymore. Has it gotten worse than before? Has it gotten better? It just sort of starts from scratch, and we lose that temporal comparison.”

Meanwhile, cases are slowly rising in BC, followed by a slight uptick in hospital admissions. The Omicron sublineage BA.2, sometimes referred to as “Stealth Omicron”, is to blame for that—the BC COVID-19 Modelling Group says it’s estimated that the variant accounts for about 80% of all new cases in the province as of this week. That can also be attributed to the fact that BA.2, the first form of Omicron, is on a simultaneous decline.

Ontario is firmly in its sixth COVID wave and is likely seeing about 100,000 new cases a day. In the past, public health leaders and experts in BC have said that what comes in Ontario will likely roll around to BC a few weeks later.

So, is it safe to say that we’re a few weeks behind Ontario now, and that we could soon see huge spikes in Omicron cases? It’s a little harder to predict now.

“We know BA.2 is rising here, just like it’s been rising in other places. And I think that’s a reasonable expectation—how that exactly shakes out, it’s hard to say,” von Bergmann said.

“Is the peak gonna be a similar height as they’re seeing in Ontario? Is it gonna be lower? We really need better local data, which we probably don’t have right now.”

In the past, the province has based the addition or removal of public health orders on the number of serious cases of COVID requiring hospitalization or ICU admission, or those resulting in death.

But in the meantime, von Bergmann said he wished the province would make that information public going forward—along with developing alternative metrics that can “fill in” for the information that’s no longer being made available, like serology studies, more frequent wastewater surveillance, and keeping the ability for British Columbians to report their own rapid test results.