New methods may be needed to catch COVID-19 virus variants in Manitoba

Samples flagged in the initial screening process are then sent to a labor-intensive process, the complete genomic sequence.

That’s what happened earlier this month. The first screening test of samples from the Manitoba indigenous community of Pauingashi and Pimi Shikamaku detected genetic mutations found in several known variants of the virus, including the more contagious B117 variant first detected in the United Kingdom. It was.

These samples were sent for complete gene sequencing, and health officials determined that they were another mutant already found in Manitoba.

An easier way to detect mutants is to develop more specific primers (fragments of genetic material used to test for viruses) that do not confuse current testing methods.

Carlos Farkas, a postdoctoral fellow at the University of Manitoba’s Rady School of Medicine, said: The varieties studied and the challenges they pose For the current test.

At a press conference on Tuesday, Dr. Brent Russan, Manitoba’s Supreme State Public Health Officer, said the test needed to be sensitive enough to not miss anything that could be a variant of concern. Said.

“We want it to be very unlikely that we will actually miss what we are looking for,” he said.

Balance of sensitivity

Designing tests to catch mutations of concern is a matter of balancing sensitivity and specificity, Rusan said.

“We need to continue our efforts to ensure that screening tests reach the right goals … to ensure that we get a little more from screening tests,” he said.

The Manitoba Institute “plans to add markers that should better distinguish between mutants of concern and local mutants,” a state spokesman said. According to a spokeswoman, this is in line with the recommendations of Canada’s COVID-19 Genomics Network.

As of Friday Three new cases announced, A total of 4 B117 mutants were confirmed in Manitoba. All four were travel-related, according to health officials.

According to a state government spokesperson, Manitoba health authorities aim to sequence about 5% of the samples received. This is consistent with other jurisdictions.

Naseem Muhajarin, a professor of epidemiology at the University of Saskatchewan, said the state needs to significantly increase the amount of samples it sends for genome sequencing to be confident that the community has not missed mutations. ..

“At some point, they need to go into more types of random tests to really see if we’re picking up variants,” he said.

Catch new variants

The virus usually mutates as it spreads, Most of those variations are not important, Says a virologist.

But determining whether a new variant is something that health officials should worry about is “not easy,” Farkas said.

One way is to study how the virus works in the laboratory. The other is to observe how it spreads in the community.

“If you live in a community with a fairly high COVID community prevalence … that might be another piece of information-if so, it’s a flag,” Muhajarin said.

Pimicikamak, also known as the Cross Lake First Nation, has been struggling to contain the coronavirus resurrection in recent weeks. Number of active cases in the community during the two days from February 12th to 14th Almost double From 42 to 82.

The band’s leader said on Friday that dozens of recent incidents, including birthday parties, wakes, and funerals, were associated with community superspreading events. Overcrowded housing in the community is another cause, Chief David Monias told CBC News.

The B117 variant is not the only concern raised by Manitoba health authorities. The same genetic marker (known as N501Y) is also found in two other major variants of concern, first detected in South Africa and Brazil.

Manitoba is waiting for the delivery of new reagents that will arrive this week. This will also allow screening for these mutants, state spokesmen said.