A false positive test is an issue that every jurisdiction has had to deal with, said Dr. Michael Patterson, during the Government of Nunavut's Monday press conference. The only Covid-19 case in Nunavut was announced as a false positive, by the top doctor today. Once again, the territory reclaimed its status as the only jurisdiction in Canada with zero Covid-19 cases.
“For us, we look at what would be the worst outcome in the event of an error. In the case of Pond Inlet, last week, the worst outcome would have been to do nothing and wait a bit and see what happens and let it spread if it was a true positive,” explained Patterson.
On April 30, the chief public health officer had announced Pond Inlet had the territory’s first Covid-19 case. A rapid response team had swabbed individuals after conducting contact tracing. All 13 swabs tested in Iqaluit were negative, revealed Patterson during last Friday’s press conference.
After sending a second set of swabs to a public health lab in Ontario, it was confirmed the tests were all negative.
It was last Friday that “we were becoming increasingly suspicious of a false positive,” said Patterson.
The patient's originally swab was retested in Ontario as evidence showed there was a need to verify the original result. Additionally, the patient was swabbed again and the samples were both tested in Iqaluit and Ontario. All these tests produced negative results.
The initial positive result had come from an Ontario lab, Patterson said.
When asked why this false positive result had occurred, the doctor responded that every lab test has a rate of false positives and false negatives. It is not due to human error. “It's something that happens with all lab tests,” he explained.
Although Patterson could not provide a specific percentage of how many tests could be false positive, he did say that “false negatives can occur certainly up to 30 per cent of the time.” This usually occurs if asymptomatic people are swabbed too early after they have been exposed to Covid-19, he said.
The doctor was confident the test result is negative for the Pond Inlet individual who was originally thought to be positive for Covid-19. “We’re as certain as we can be,” he said.
According to the current information available, this Pond Inlet individual has not been outside of community for some time. Neither exposure to Covid-19 nor cases of the disease have been identified within Pond Inlet. There have also been no noticeable increases or changes in significant respiratory infections in the community, said Patterson.
“For all of these reasons, we believe that the individual in Pond Inlet does not and never did have Covid-19,” he explained.
The rapid response team, who was sent to Pond Inlet on April 30, will stop its operations. The members of the team will leave the community and start preparing for possible future deployments.
When Patterson was asked what lessons have been learned from this first emergency response, the chief public health officer said it was too early to assess as it required a discussion with the health staff.
He did however mentioned the initial deployment worked “very well.”
The aim was to have the rapid response team in Pond Inlet within 24 hours from when health staff were notified of the positive result. The team was successful in sending swabs for testing long before 24 hours, said Patterson.
As of today, all additional measures specific to Pond Inlet that had resulted due to positive Covid-19 case are lifted.
On April 30 Patterson announced that all passenger travel, including land travel, in and out of Pond Inlet was banned. This travel ban was put into place to minimize the risk of Covid-19 from spreading to multiple communities at once. All businesses except for grocery stores, fuel and motor vehicle stations, post office and restaurant take-out services were ordered to be closed. No social gathering in dwellings were permitted, while social gatherings outside were restricted to five people or less.
“I'd like to apologize to Pond Inlet for the inconvenience we caused them, I caused them, and thank them for the hard work and co-operation (during) these last five or six days,” said Patterson.