TORONTO (AP) — Canada most populous province on Monday reported its first case of a coronavirus variant first identified in South Africa that is believed to be more contagious than the original.

Dr. David Williams, Ontario’s chief medical officer of health, said the case was found in the Peel region outside Toronto and the person does not have a known history of travel or any known contact with someone who has travelled.

British Columbia has also reported cases of the South African variant.

Viruses constantly mutate but scientists are especially concerned about the emergence of three that researchers believe may spread more easily. One first reported in the United Kingdom was previously confirmed in Canada, and Ontario has dozens of cases now.

The variant first found in South Africa was detected in October. Since then, it has been found in at least 30 other countries including the U.S.

The discovery comes as the pandemic-weary Ontario government is thinking of reopening schools in Canada’s largest city of Toronto and its suburbs.

Scientists recently reported preliminary signs that some of the recent mutations may modestly curb the effectiveness of two vaccines, although they stressed that the shots still protect against the disease.

The coronavirus has killed roughly 20,000 in Canada.