The Northwest Territories confirmed its first case of Covid-19 on Saturday morning, hours before the territory is expected to close its borders to all but essential travel.

The territory said the individual’s condition had improved and they are recovering at home.

They are a Yellowknife resident who travelled to Alberta and British Columbia. They returned to Yellowknife in the second week of March by plane.

They had no symptoms on the aircraft but developed mild symptoms three days after their return, NWT chief public health officer Dr Kami Kandola said. The exact flight taken was not given – public health professionals are tracing and notifying people who may have had contact.

They went for a Covid-19 test earlier this week and the result was returned to the NWT late on Friday night, after the territory had declared its plan to close the border on Saturday.

NWT residents are now being urged to take every available precaution, including social distancing for everyone and immediate self-isolation if you have any symptoms.

More: NWT government advice on what you need to do

More: Who to call if you need advice on self-isolation or symptoms

More: How to self-isolate

The NWT says it has ordered “an aggressive testing strategy” to identify cases and respond to them. So far, 299 tests have been completed – 298 were negative.

On Saturday the territory formally closed its borders to all but essential travel, allowing NWT residents and vital workers in but shutting out all others.

The closure comes as part of an order introducing a new range of measures that can be enforced by law, with up to a $10,000 fine or six-month jail term if disobeyed.

More: Read the NWT’s announcement of the first confirmed case

The territory had previously said it would not confirm the location of positive tests in order to protect privacy.

In this instance, the chief public health officer said, the size of Yellowknife meant the individual’s privacy could be assured. The location of further positive tests, if they happen, is unlikely to be made public.