WINNIPEG -- With cases of the B1.1.7. variant reported in Manitoba, the province's top doctor is introducing new rules when it comes to self-isolating that will require more people to go into quarantine when a COVID-19 case is identified.

Dr. Brent Roussin, the chief provincial public health officer, said on Monday to address the introduction of variants of concern in Manitoba, the province is making its contact management "more aggressive."

Roussin said the guidance has changed for the threshold of prolonged contact. It has decreased from 15 minutes to 10 minutes.

"This is a guide. If there (are) high-risk contacts, where we feel somebody was absolutely exposed to droplets, then that could be as little as just a few seconds or minutes," Roussin said.

"We will have more people identified as close contacts, so more people will be required to self-isolate."

Roussin said for those people identified as close contacts – there are new rules for self-isolation.

Any person in the same household as a positive case is deemed a close contact, Roussin said.

If a close contact of a positive case is identified, everyone in that close contact's household will also be required to self-isolate until the close contact has been tested and receives a negative result.

He said any close contacts with no symptoms will be advised to get tested 10 days after the last exposure. Roussin said close contacts will be required to self-isolate for a minimum of 14 days regardless of testing results.

"That’s because the incubation period of this virus is up to 14 days," Roussin said.

These changes come as a total of four cases of the B.1.1.7. variant – which was first discovered in the United Kingdom – have been reported in the province. No new cases of the variant were reported on Monday.

Roussin said the variants are not the only reason for the beefed-up self-isolation requirements. With public health orders being loosened in the province, he said stronger rules on contact tracing and management are needed.

"We need to be able to get more aggressive on the other side or we're just going to see those case numbers climb again," he said.