SUDBURY -- Three health units in northeastern Ontario have now received notice from the province that a confirmed positive COVID-19 test result has detected a highly-transmissible variant.

Health officials said up until Feb. 3, COVID-19 test samples that met certain criteria were screened for variants using a two-part test. Now, Ontario Public Health Laboratories is screening all positive COVID-19 tests for the variants.

"An initial test looks for a mutation and if positive, there is a high probability that the mutations are of a variant of concern. The second part of the test is a whole genome sequencing test to determine the exact COVID-19 variant," the Sudbury health unit said in a news release on Jan. 25.

It is the second part of the testing that will determine if the variant is of concern or not, a key difference.

The first variant detected in northeastern Ontario was in the Public Health Sudbury & Districts' area on Jan. 24 and involved a person with a history of international travel.

"The rate at which these new variants spread is, of course, alarming as we have seen in other areas of the province and parts of the world. We need to do everything in our power to slow to the spread for as long as we can," said Dr. Penny Sutcliffe, the medical officer of health for the Sudbury and Manitoulin Districts. "I am very pleased to note that our quarantine and isolation practices are working."

Two more northeastern health units, North Bay Parry Sound District Health Unit and Porcupine Health Unit, said in news releases on Thursday that mutations have been detected in their areas as well.

North Bay Parry Sound District Health Unit said the case in its area was detected in someone who had also travelled internationally.

"The preliminary results of COVID-19 Variant of Concern confirms the need for everyone to remain cautious and assume everyone outside your home has COVID-19," Dr. Jim Chirico, medical officer of health for the North Bay and Parry Sound area."Our district has been doing great with keeping the number of individuals who have tested positive for COVID-19 low, but as we've seen with the outbreaks in long-term care homes, associated to COVID-19 Variants of Concern in southern Ontario, the variants can be devastating. We must not let our guard down and we need to continue to follow public health guidelines."

Porcupine Health Unit said the case in the Cochrane District involves an individual linked to the COVID outbreak at Extendicare Kapuskasing, which has infected 68 people and has resulted in 11 deaths due to the disease.

Officials with the long-term care home said as of 11 a.m. Thursday morning, the facility has 46 active cases of COVID-19, 15 involving staff members and 31 residents.

Despite the Ontario-wide lockdown that began on Dec. 26, northeastern Ontario has had 682 new infections of COVID-19 confirmed and 556 cases resolved, including 21 deaths since Jan. 11.

As of Thursday at 4 p.m., northeastern Ontario had 156 active cases of COVID-19 after eight new infections were confirmed and 27 cases resolved.