No ongoing transmission associated with COVID-19 case at N.W.T. mine, officials say

N.W.T. health officials say they have identified the "likely source of the infection" in a case of COVID-19 at a diamond mine near Yellowknife last week, and there is no indication of ongoing transmission.

‘Likely source’ identified of COVID-19 case at Gahcho Kué diamond mine

Last Wednesday, a presumptive positive case was identified at the Gahcho Kué Diamond Mine, which later turned out to be a false-positive. Two days later, another employee tested positive. (Darryl Dyck/The Canadian Press)

An individual who recently travelled outside of the Northwest Territories was the likely source behind the positive case of COVID-19 at the Gahcho Kué mine, according to the office of the chief public health officer.

There is currently no indication of ongoing transmission of the virus either, the office said in a news release on Monday.

The case at Gahcho Kué was identified on Friday. Officials said the person is a mine worker who lives in Yellowknife.

The "likely source of the infection" was identified by public health after what it says were "extensive interviews with the individual" at the mine.

"Through this investigation, there was only one high-risk contact identified," says the office.

It says the contact was tested and the results were negative, which isn't uncommon, according to the release, because the person was tested late in the potential incubation period.

It's unclear where or when the two individuals came into contact.

Public health also tested other people who spent time with the likely source during the potential infectious period. It says all the tests came back negative.

The public health office called for calm in the territory while encouraging residents to keep following public health measures.

'Clerical error' blamed for false positive

Meantime, a "clerical error" is being blamed for an earlier, false-positive test result at Gahcho Kué last week, according to health officials.

The apparent mix-up also delayed identifying the Yellowknife worker at the same mine who later tested positive.

Several workers who were in contact with the false-positive case were initially tested — then retested — for COVID-19.

"After an investigation, it has been determined that a clerical error caused the incorrect sample to be sent for reassessment by Stanton Territorial Hospital's lab," reads a statement from the office of the territory's chief public health officer Monday.

"This is why there was initially a false positive reported, and why the confirmed case was not identified in the first round of testing."

The statement did not offer any more details, and referred any questions to GuardRX, which runs a testing lab at the nearby Diavik diamond mine.

The company's CEO Gary Kobinger said a statement to CBC News on Tuesday the error was made by one of the company's technicians .

"The clerical error was from a mislabelling of the positive tube for the tube next to it that was negative," he wrote. The error led to the wrong sample being sent out.

Kobinger said the company has performed more than 53,000 tests in the past four months and this is the first mislabelling error, which was detected in less than 48 hours.

He said several changes have since been implemented, including adding "a second pair of eyes" to double check the work, and he said that all future positives will be confirmed internally.

The confusion comes as the territory confirmed four positive cases in less than a week — one at Gahcho Kué, two in Yellowknife and one in Inuvik — after going months without a single case.

The office of the chief public health officer also said in the Monday news release that three of those people have now recovered.

With files from John Van Dusen


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