Province looks to ‘pooling’ to boost COVID-19 testing

Combining asymptomatic coronavirus samples should cut processing time

With a return to school only two weeks away, Alberta Health Services is quickly ramping up plans to increase COVID -19 testing capacity, including by piloting a new testing technique where samples from multiple Albertans are combined and processed at the same time.

AHS began piloting the practice called “pooling ” on some asymptomatic novel coronavirus samples on Aug. 14.

Pooled tests mix biological samples from several people before testing.

If the combined sample tests negative for the novel coronavirus, lab officials consider all samples involved to be negative.

If the combined sample tests positive, however, all individual samples are tested alone to determine which sample or samples are positive.

“Pooling samples is an effective approach for performing a large number of tests while using fewer laboratory supplies and staff,” said AHS spokesman James Wood in a statement. “If successful, (AHS) will look to expand this practice over the coming weeks to increase capacity.”

At her Thursday update on COVID-19, Dr. Deena Hinshaw, Alberta’s chief medical officer of health, said that of the 316,000 asymptomatic tests that had been conducted to that point, only 0.1 per cent had returned positive.

At that rate, even if five asymptomatic samples are tested at once, the chance of a positive test among the pool would be less than half a per cent.

The pooled testing is just one way Alberta is planning to boost testing capacity ahead of September. Hinshaw said in early August that the province hoped to double capacity.

Currently, Alberta has the ability to test up to 16,000 people per day, but average test daily rates hover around 8,000. On Aug. 5, AHS put out a call for proposals to private vendors that can perform COVID-19 swabbing and testing on a contract basis, particularly for asymptomatic tests in rural areas.

All proposals are expected to be submitted by Monday.

Even after private groups begin testing, AHS said it would continue to perform all testing of Albertans who are symptomatic, are close contacts with a known case or are in outbreaks or continuing-care settings.

The province is also hiring extra data-entry clerks and lab assistants to lighten the load within Alberta Precision Laboratory settings.

“As well, APL is securing additional automation for COVID -19 testing,” Wood said.

“These approaches will help improve overall efficiencies, reduce wait times for results and allow us to increase our daily COVID -19 swabbing and testing capacity.”

More details on testing expansion from Hinshaw are expected in the coming weeks.

Alberta has now performed more than 800,000 tests for the novel coronavirus, setting pace to break the million-test mark in the first week of September.

About one in every seven Albertans has been tested for COVID -19 at least once, Hinshaw said on Thursday.

These approaches will help improve overall efficiencies, reduce wait times for results ...