COVID-19 prevalence high and rising across most of province as BCCDC revamps reporting dashboards

The BCCDC's new "Viral Respiratory Outcomes" dashboard is seen in this screenshot from Oct. 3, 2024. (bccdc.ca)

The prevalence of SARS-CoV-2 – the virus that causes COVID-19 – in B.C. wastewater is high and rising across most regions, according to the latest data from the B.C. Centre for Disease Control.

The BCCDC released its first weekly data update of the 2024-25 respiratory illness season Thursday, and took the opportunity to dramatically revise the information it presents and the way it is presented. 

Gone is the previous year's "COVID-19 Situation Report" dashboard, replaced with a new dashboard titled "Viral Respiratory Outcomes."

While the situation report included specific numbers for newly confirmed infections, hospital admissions, critical care admissions and deaths within 30 days of a positive COVID test, the new dashboard reports the latter three numbers as a rate per million residents.

The Viral Respiratory Outcomes report does not include new infection totals at all, though that information – alongside test positivity rates and positive test counts for other respiratory viruses – is available on a separate dashboard. 

Wastewater data

The BCCDC has also revised how it presents wastewater data, adding clear definitions for "high," "moderate" and "low" concentrations of SARS-CoV-2 and other viruses, as well as indicators of the ongoing trend in each region. 

According to Thursday's update, wastewater facilities in every regional health authority except Island Health showed "high" levels of the COVID-19 virus.

To reach this conclusion, the BCCDC averages the viral load per capita at all monitored wastewater treatment plants in a given region and compares it to "the distribution of all averaged viral load per capita data in the most recently completed respiratory season," a period stretching back roughly to the end of August 2023.

If the latest data is above 75 per cent of last respiratory season's average, the viral concentration in a given region is considered "high."

Island Health's COVID concentrations were "moderate" in this week's update, a label reflecting a range between 25 and 75 per cent of last year's average. Concentrations below 25 per cent of last year's average would be considered "low."

The four health authorities with high viral concentrations also showed a "statistically significant increasing trend" in their wastewater during the last epidemiological week, according to the BCCDC, while Island Health showed a "statistically significant decreasing trend."

Hospitalization data

The exact number of test-positive COVID-19 patients in B.C. hospitals as of Thursday – a number CTV News has been tracking and graphing since the start of the pandemic in 2020 – is no longer available.

In its place, the BCCDC is now publishing a seven-day rolling average of the hospitalization total, with the most recent published data corresponding to the end of the last epidemiological week, in this case, Saturday, Sept. 28.

Previously, the agency's weekly updates included the total number of people hospitalized as of the date of the report. It was the only statistic the BCCDC reported in real time. All of the other data reported was from the most recent epidemiological week, meaning it was at least five days old by the time it was published. The timeliness of the hospitalized population data was part of the reason CTV News continued tracking it.

As of Sept. 28, the seven day rolling average for the number of test-positive COVID-19 patients in B.C. hospitals was 205.71. That's a substantial increase from where the average stood a week earlier, on Sept. 21, when it was 181.71. However, the total remains well below where it was in previous years.

The BCCDC's revamped data shows a seven-day rolling average of 316.43 on Sept. 28, 2023, and an average of 328 on Sept. 28, 2022.

Cases and severe outcome rates

During the most recent epidemiological week, which spanned Sept. 22 through 28, the province conducted 3,488 lab tests for SARS-CoV-2, and 632 of them came back positive.

That works out to a test positivity rate of 18.1 per cent, up from 17.2 per cent the week before.

Other respiratory viruses are not yet circulating in high numbers, according to the BCCDC data, which shows positivity rates for Influenza A and RSV at 1.9 per cent and 0.2 per cent, respectively.

For COVID, the rates of severe outcomes – hospital admissions, critical care admissions and deaths within 30 days of a positive test – were 14.1 per million, 2.5 per million and 2.6 per million, respectively.

Those rates can be used to extrapolate province-wide totals of at least 80 new hospital admissions, 14 critical care admissions and 14 deaths during the epidemiological week in question, though it should be noted that the BCCDC's data for these categories is typically incomplete when it is first reported and is adjusted upwards in subsequent weeks.

The BCCDC says the change to rates rather than raw numbers is intended "to make comparisons between health regions, age groups, or respiratory seasons more accurate and meaningful."

The new Viral Respiratory Outcomes dashboard includes tabs that allow users to make such comparisons.

During the most recent epidemiological week, Northern Health had the highest rate of hospital admissions per million, at 29.67. It also had the highest rate of critical care admissions, at 6.59 per million.

Interior Health had the highest death rate, at 5.56 per million.