The Omicron variant, first sequenced in South Africa, has been identified in at least 12 other countries.

Most have so far reported imported cases spotted in travelers from the African nation and other places. Still, the spread shows the difficulties of curtailing new strains of COVID-19.

Israel, for instance, said a confirmed case who arrived from Malawi rode on a bus from Tel Aviv. Italy’s first case traveled around the country for days before testing positive.

Researchers worldwide are racing to understand the full impact of the new strain and governments have banned travelers from South Africa and nearby countries on concerns Omicron could evade the protection of vaccines or fuel new Covid surges.

Here’s how far Omicron has reached:

South Africa: Early samples of PCR tests showed that 90% of 1,100 new cases reported midweek in the South African province that includes Johannesburg were caused by the new variant

Botswana: At least 19 cases detected

UK: At least three confirmed cases linked to travel in South Africa

Germany: Two cases in travelers who arrived at Munich airport from South Africa, AFP reported, citing regional officials.

Netherlands: Thirteen cases detected among travelers from South Africa

Denmark: Two cases in arrivals from South Africa

Belgium: One case

Israel: One confirmed case and other suspected ones, as of November 27

Italy: One case who moved around the country before testing positive

Czech Republic: One case, according to local media

Hong Kong SAR: Two cases in quarantine hotel

Australia: Two cases in Australia’s New South Wales state. Both had traveled from South Africa

Canada: Two cases who had recently traveled from Nigeria