The public health laboratory says providing precise figures for variant cases is challenging, in part because of the delay to complete whole-genome sequencing and because not all the samples can be sequenced. (Medicago)

The public health laboratory says providing precise figures for variant cases is challenging, in part because of the delay to complete whole-genome sequencing and because not all the samples can be sequenced. (Medicago)

Variants of concern higher than reported, but giving precise data challenging: BCCDC

Director Mel Krajden attributes it to a delay to complete whole-genome sequencing and not all the samples can be sequenced

A medical director at the British Columbia Centre for Disease Control says the number of active COVID-19 cases that are variants of concern is higher than what has been publicly reported in the province.

But Mel Krajden, director of the centre’s public health laboratory, says providing precise figures for these variant cases is challenging, in part because of the delay to complete whole-genome sequencing and because not all the samples can be sequenced.

Data scientists have been calling for more timely, comprehensive information about the variants of concern in B.C. in order to help residents understand the seriousness of the threat and to persuade those who are ignoring public-health orders to follow them.

Dr. Bonnie Henry said this week that only three per cent of B.C.’s active cases are variants of concern, referring to those that have been confirmed through sequencing. Krajden acknowledged that is “not an accurate representation” of what is happening in the province.

“The numbers are high. Let’s not con ourselves. The numbers are high and they’re not going to get lower. Because this is the same trajectory that we’re following, that Alberta’s following, that Ontario’s following, so we’re not going to get out of this,” he said.

“Either that or you shut down the whole economy, and we’ve been reluctant to be so draconian.”

He said variant of concern cases are doubling about every eight to 10 days and will ultimately replace other COVID-19 strains. But he also said scientists are tracking the variants in a range of ways that go beyond just quantifying them.

“They’re looking at the trends. They’re looking at the people in hospitals. They’re looking at the severity of disease,” he said. “It’s being looked at from many, many different angles, to find: ‘What’s the right solution?’”

Experts say that B.C.’s reliance on time-consuming whole-genome sequencing is not necessary to report cases that are variants of concern. The province already quickly screens about 90 per cent of cases for a mutation that the three major variants have in common.

Ontario reports the number of presumptive variant cases every day based on this quick screening process. It then does whole-genome sequencing on some samples to distinguish between the P.1 variant first identified in Brazil and the B.1.351 variant first found in South Africa.

Health officials in B.C. have been reluctant to provide the numbers of presumptive variants of concern because some samples could end up being so-called “variants of interest” that have not been shown to be more transmissible, such as the strain first detected in Nigeria.

However, experts say that the current numbers being given only after confirmation by whole-genome sequencing are not accurate either, because B.C. does not have the capacity to sequence every case.

New data provided by the BC Centre for Disease Control gives insight, for the first time, on the number of presumptive variant cases being picked up by quick screening as part of the PCR test from January through March.

In the second week of January, there were two presumptive variant of concern cases. By the first week of February, there were 22, and by the first week of March there were 438. In the final week of March, there were 2,514, or 51 per cent of B.C.’s positive cases.

Cases confirmed through sequencing in the week of March 21 show 1,183 cases, or 21 per cent of B.C.’s positive cases. This same week, Henry told reporters that the portion of cases that were variants of concern was in the “high teens” to “early 20s.”

The centre for disease control notes that there is a weeklong delay for whole-genome sequencing. Krajden said the province has the capacity to sequence about 1,900 cases a week, though the data shows more than 2,000 cases were sequenced the week of Mar. 21.

Whole-genome sequencing for the final week of March has not yet been completed, and Krajden said the province stopped trying to sequence all variant of concern cases as of April 1.

“What we wanted to make sure is that we don’t waste our energy on confirming a U.K. variant,” he said, adding that sequencing will still be necessary to distinguish between the variants first identified in Brazil and South Africa.

“What we’re really trying to do is be as clear as possible about what’s circulating, what are the risks, are we able to detect enough variants of interest, can we do the correlations between what happens to someone who has one of these variants.”

Henry said earlier this week that the province was still sequencing all presumptive variant of concern cases. She indicated, though, that it might stop sequencing those presumed to be the B.1.1.7 variant first identified in the U.K.

The Health Ministry did not immediately respond to a request for comment.

Krajden explained that there are other challenges involved in reporting accurate numbers of variant of concern cases.

Different laboratories use different screens as part of their PCR tests, with St. Paul’s Hospital, for example, developing a screen that can distinguish between the three major variants, while others may only pick up the mutation associated with all three.

Another issue is that some samples can’t be sequenced because the amount of viral load isn’t high enough, he added.

He said he understands the public is being “driven crazy” and wants more precise data, and his centre is trying to present the information in as accurate and clear a way as possible.

But he stressed the ultimate goal was immunizing all eligible adults who want the vaccine.

“The endgame is through vaccination, converting a virus that causes severe … disease and death in predominantly the elderly into a virus that causes basically the typical common cold.”

CoronavirusHealth

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Wounded Warriors runners run along Beaver Creek Road towards the Beaver Creek Volunteer Fire Department hall. (ELENA RARDON / ALBERNI VALLEY NEWS)
Port Alberni’s Wounded Warriors stage solo run

Vancouver Island-wide event was cancelled, but Maria Marciano and Dave Nesbitt ran anyway

Wickaninnish (Clifford Atleo) plays the drum while singing the Nuu-chah-nulth song on the court steps in Vancouver In a picture from April 2018. Photo credit, Melody Charlie.
Five Nuu-chah-nulth Nations celebrate legal victory in fishing dispute

Ha’oom Fisheries Society and T’aaq-wiihak Fisheries announce “major legal victory”

Winston Joseph, known as Mr. Positive Port Alberni, leads the 2019 Canada Day parade with his wife Sheila. Winston, who was integral in starting the July 1 folkfest, died April 11, 2021 at the age of 89. (PHOTO COURTESY SONJA DRINKWATER)
Community remembers Winston Joseph with Canada Day parade in April

‘Mr. Positive Port Alberni’ started Canada Day folk fest, lived a life of service and faith

Grade 5 Wood Elementary Students cycling on the powerline trail. (SUBMITTED PHOTO)
Wood School bicycles, equipment worth $8,000 stolen

Equipment was stored at Echo Fieldhouse in Port Alberni

Alberni Valley Bulldogs forward Kobe Assam battles for the puck despite being knocked to the ice during a physical first period against the Cowichan Valley Capitals on April 7. (ELENA RARDON / ALBERNI VALLEY NEWS)
BCHL: Alberni Valley Bulldogs pick up second shutout against Cowichan

Braden Blace earns first BCHL goal and game-winner

In this image from NASA, NASA’s experimental Mars helicopter Ingenuity lands on the surface of Mars Monday, April 19, 2021. The little 4-pound helicopter rose from the dusty red surface into the thin Martian air Monday, achieving the first powered, controlled flight on another planet. (NASA via AP)
VIDEO: NASA’s Mars helicopter takes flight, 1st for another planet

The $85 million helicopter demo was considered high risk, yet high reward

University of Victoria rowing coach Barney Williams is photographed in the stands during the Greater Victoria Invitational at CARSA Performance Gym at the University of Victoria in Victoria, B.C., on Friday, November 29, 2019. The University of Victoria says Williams has resigned effective immediately. (THE CANADIAN PRESS/Chad Hipolito)
University of Victoria women’s rowing coach resigns by mutual agreement

Lawsuit filed last summer accused Barney Williams of verbal abuse

Former B.C. premier Christy Clark. (Black Press Media files)
Former B.C. premier to testify at money laundering hearing today

Attorney General David Eby has been added to the witness list as well

Selina Robinson is shown in Coquitlam, B.C., on Friday November 17, 2017. British Columbia’s finance minister says her professional training as a family therapist helped her develop the New Democrat government’s first budget during the COVID-19 pandemic, which she will table Tuesday. THE CANADIAN PRESS/Darryl Dyck
B.C. to table budget that’s expected to deal with COVID-19 pandemic and beyond

Robinson released a fiscal update last December that said the impact of the pandemic on B.C.’s economy was uncertain

Paramedic Matthew Schlatter of Victoria is living a fuller life today due to the double lung transplant he received in 2019. He encourages B.C. residents to register as an organ donor and let their families know their wishes. (Instagram/Matthew Schlatter)
B.C. man living a full, active life after double-lung transplant

Matt Schlatter encourages people to register as an organ donor to help others live

(Photo by Mojpe/Pixabay)
Canadian kids extracting record amounts from Tooth Fairy

Our neighbours in the U.S. receive slightly less from Tooth Fairy visits

Families of two of three workers killed in a train derailment near Field, B.C., in 2019 have filed lawsuits accusing Canadian Pacific of gross negligence. The derailment sent 99 grain cars and two locomotives off the tracks. THE CANADIAN PRESS/Jeff McIntosh
Families of workers killed in Field train derailment allege negligence in lawsuit

Lawsuits allege the workers weren’t provided a safe work environment

Cannabis bought in British Columbia (Ashley Wadhwani/Black Press Media)
Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

Most Read