Alberta’s R-value creeps back above 1 as province logs 328 more cases

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Transmission of COVID-19 in Alberta could be back on an upward trajectory, according to a key metric.

Alberta’s virus reproduction rate — also known as the R-value — is back above 1, according to Univeristy of Toronto epidemiologist Dr. David Fisman, who pegged the number at 1.09 Saturday.

The R-value indicates the rate of virus spread; a value of 1 means that each case leads to one more case, on average. A higher number means rate of transmission is increasing exponentially, while a lower number signals a decline.

The number is an estimate, calculated by epidemiologists by working backwards and factoring in metrics including case counts, hospitalizations and mortality.

University of Calgary developmental biologist Malgorzata Gasperowicz said the R-value needs to remain well below one in order to see case counts shrink, especially as new, more contagious variants threaten to further accelerate transmission.

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“We know now from other jurisdictions these variants are 30 to 50 per cent more transmissible,” Gasperowicz said. “(The variants) have this intrinsic possibility to double every seven to 10 days, if it’s not contained, if it’s out of control, so we have a very dangerous animal there.

“It’s a super-danger. It’s playing with fire.”

Alberta reported nine new cases of the B.1.1.7 strain first found in the United Kingdom Sunday, and another 14 Saturday. The province has detected a total of 278 variant cases, seven of which are the B.1.351 strain that originated in South Africa. Those numbers include retesting of historical swabs.

Alberta Health calculates and publishes the R-value weekly, on Mondays. The province’s most recently posted value, from Feb. 15, was a provincewide R-value of 0.85, with the province’s rural zones seeing an elevated rate of 0.94.

The province said they were closely monitoring spread of the virus in Alberta through the reproductive rate as well as other statistics.

“As (chief medical officer of health) Dr. (Deena) Hinshaw has stated, COVID-19 is still here and cases can rise again if we all do not keep following the health measures in place. We are all still protecting each other,” said Alberta Health spokesperson Tom McMillan.

Gasperowicz said she wasn’t surprised to see the R-value rise this weekend, just under two weeks after the province eased some restrictions in the sectors of dining, indoor fitness and youth sports.

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She said while there aren’t enough data points yet to say with confidence that Alberta will see another growth in cases, she advocated for a strategy of a short, severe lockdown to eradicate viral spread in the community and avoid a third wave driven by variants.

“If we do a lockdown in March and April, it won’t give us the normalcy back, but if it was implemented now we could have a nice summer, with almost no COVID,” Gasperowicz predicted.

Alberta logs 328 new cases Sunday, 380 Saturday

Alberta detected another 328 cases of the novel coronavirus Sunday from about 7,500 tests, representing a positivity rate of about 4.5 per cent.

The province’s rolling seven-day average positivity rate has seen a small uptick over the past week after gradually declining since the start of 2021. Alberta’s average positivity rate over the last week is now 4.4 per cent, up from a low of 3.7 per cent reached Feb. 10.

Earlier in the weekend, Alberta logged 380 new COVID-19 infections and another 4.5 per cent positivity rate Saturday.

Different regions of the province have seen vastly different positivity rates over the past week. In the Alberta Health Services Calgary zone, just more than three per cent of cases have returned positive. The number shoots to above 10 per cent in the North zone.

Alberta Health reported an additional nine deaths Sunday and seven Saturday, bringing the provincial death toll to 1,827.

Of the nine deaths reported Sunday, only two took place in February, both deaths linked to long-term care facilities that occurred on Feb. 19. The remaining seven deaths all happened prior to Christmas, and included three individuals from the Calgary zone.

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McMillan explained these deaths were not linked to virus outbreaks and were only determined to have COVID-19 as a contributing cause post-mortem.

“When in doubt, we have the death certificate and file reviewed post-mortem to determine if COVID-19 was a contributing cause. This can sometimes take time for cases where there was no readily apparent link to COVID-19,” McMillan said.

“As a result of this thorough process, we are able to report the most accurate total possible. This includes identifying community cases that otherwise may not have been linked to COVID-19.”

After a brief plateau, hospitalization rates continued to drop over the weekend. As of Sunday, there are 321 Albertans in hospital with COVID-19, including 53 in intensive-care units. It’s the second straight day Alberta saw a five per cent drop in total hospitalizations, down from 336 patients in hospital Saturday.

Alberta now has 4,758 active cases of COVID-19, down from 4,840 at the start of the weekend.

Through end-of-day Saturday, Alberta has administered 169,441 doses of vaccine, with 66,357 Albertans fully immunized after receiving two doses.

The pace of vaccinations is expected to accelerate dramatically in the coming weeks, as seniors born in 1946 or earlier will be able to book immunization appointments beginning Wednesday amid heightened supply of vaccine.

An online portal to book those vaccines as well as information on booking by phone will be available at that time at alberta.ca/vaccine.

jherring@postmedia.com

Twitter: @jasonfherring