This article and its accompanying graphics are being regularly updated by our team of journalists. The last update was on December 16.
First detected in South Africa, the potentially more virulent Omicron COVID-19 variant is now spreading around the world. Following its discovery at the end of November, there have now been confirmed cases of the variant detected in 85 countries worldwide, according to the European Centre for Disease Prevention and Control (ECDC).
While data is still being gathered as to the severity of the symptoms, according to the UK government, at least one case has been attributed to Omicron so far.
European countries were among the first to report cases but the variant has yet to be detected everywhere on the continent. So, which countries have either suspected or confirmed cases of the new variant?
Here are the latest updates from across the continent along with maps to track the variant as it spreads.
The Austrian government announced it had confirmed one case - a man from the Tyrol region who had recently travelled to South Africa - on November 29. According to the European Centre for Disease Prevention and Control (ECDC), the country has now confirmed a further 70 cases as of December 16.
The country identified the first case of the Omicron variant on European soil on November 26. According to the Belgian public broadcaster RTBF, the patient is a young woman who had been in Egypt and had been showing symptoms for 11 days. Since then, a total of 121 cases have been officially linked to the new variant, including cases not linked to travel to South Africa.
Croatia recorded its first suspected cases of the variant on Monday, the country's health authorities confirmed. The source of infection has not been determined but it is believed the two cases were infected at a business meeting, Bernard Kaic, an epidemiologist at the state health institute, said. Croatia has now confirmed three cases as of December 16.
Cyprus has detected its first cases of the Omicron variant of COVID-19, its health ministry said on Friday December 10. It said three cases were isolated in the southern city of Limassol following specialised tests by Cyprus's Institute of Neurology and Genetics.
None of those who tested positive for the variant required hospitalisation, the health ministry said. The individuals had recently travelled from abroad.
A regional hospital in Liberec, in the north of the Czech Republic, announced on November 27 the discovery of the Omicron variant in a patient with COVID-19.
The woman, who was vaccinated and had mild symptoms, had travelled to Namibia before returning to the Czech Republic via South Africa and Dubai. Cases have risen up to 10 cases as of December 16.
Denmark has reported 383 cases so far as confirmed through whole-genome sequencing (WGS) and a further 5,664 confirmed nationally through a variant-specific PCR testing.
The SSI public health institute first confirmed the presence of the variant in the country on November 28 with two people confirmed cases. A school in Odense was closed the following day pending the results of sequencing analysis following a suspected case of COVID-19 discovered in a student.
A total of 26 COVID-19 Omicron variant cases have been identified in Estonia, six of which have been confirmed during sequencing. Most cases involve travelling from South Africa.
The number of identified cases in Finland was 34 on December 16, according to the Finnish Institute for Health and Welfare (THL). The majority of infections are related to travel.
As of December 16, France has now identified 170 positive cases of the Omicron variant, including people returning from southern Africa as well as local infection, according to the French health minister Olivier Veran.
The first known case was in Reunion, one of France's overseas departments, in a traveller returning from Mauritius after a trip to Mozambique.
Initially, two cases of infection with the Omicron variant had been confirmed by the health authorities in the southern German state of Bavaria. The two travellers arrived at Munich airport, having returned from South Africa.
There are now 102 known cases, according to the latest figures from the ECDC. As well as new restrictions, Germany is moving towards making vaccination against the virus mandatory.
Greece has identified 10 positive cases of the Omicron variant as of December 16. A man on the Greek island of Crete who tested positive for COVID-19 was suspected of having the first Omicron variant in the country. He had recently returned from South Africa.
Although according to the ECDC, two cases of the Omicron variant has been detected in Hungary so far. In addition, according to the Israeli Ministry of Health, there is a coronavirus-infected person who was detected after returning from Hungary (reported our colleagues based In Budapest).
Despite putting border restrictions in place in the wake of the discovery of the Omicron variant, Icelandic health authorities announced on December 1 that they had detected a case of the variant in the country in a person who hadn't travelled. Their conclusion was it was locally transmitted and therefore the variant had been in Icelandic society for a while already. The number of confirmed cases is now sitting at 40 as of December 16.
The number of confirmed Omicron cases has increased to 42 in total as of December 16, according to data from the ECDC.
"Given the evidence of community transmission of Omicron elsewhere in the Common Travel Area, we would once again advise people to take a Lateral Flow COVID-19 test before travelling to Northern Ireland from England, Scotland, Wales or the Republic of Ireland," Chief Medical Officer Professor Sir Michael McBride said.
The country one its confirmed Omicron case in a man from the Naples region who had returned from Mozambique, the Italian Higher Institute of Health (ISS), announced on November 27. The ISS had said the patient and his family are in good health. Italy has now confirmed 27 cases, according to the latest ECDC data. Meanwhile, the country has imposed fresh restrictions, including a new basic health pass that requires a negative test to use public transport and hotels.
Latvia's first two Omicron cases were confirmed on December 5. The virus variant was detected after saliva samples taken at Riga International Airport on December 4 were tested using genome sequencing. The total number of cases rose to 14 as of December 1.
Lithuania's National Public Health Laboratory (NVSPL) tested and confirmed the country's first two cases, Vice Health Minister Aušra Bilotienė-Motiejūnienė announced on December 14. The cases have been linked to a single source. Samples from additional suspected cases are currently undergoing testing.
Testing at Amsterdam's Schipol Airport found that 61 out of 600 passengers recently arrived from South Africa have tested positive for COVID-19. The Dutch authorities confirmed on December 4 the presence of the new variant in 18 of them so far.
The infected passengers had arrived on two flights from South Africa which took off on November 26 just as new travel restrictions were being brought in.
As of December 16, the total number of confirmed cases is 123.
In what has been described as the biggest single outbreak outside of South Africa, 19 Omicron cases were confirmed in Oslo after an office Christmas party. Up to 60 others tested positive for COVID-19 at the "superspreader event". Those who tested positive for the variant were also vaccinated.
Another suspected case of the variant was announced on December 6 after a crew member onboard a Norwegian cruise ship which docked in New Orleans in the US tested positive for COVID-19.
As of December 16, 1,792 cases overall were confirmed.
Omicron was detected in 13 players from the Belenenses SAD football club following a trip to South Africa by a member of their squad.
In a press release on November 29, the National Health Institute (Insa) revealed that "preliminary tests strongly suggest that all thirteen cases (...) are linked to the variant of concern Omicron".
There are now 69 confirmed cases in the country as of December 16, according to the ECDC.
The country confirmed its first case of the Omicron variant in a 30-year-old Lesotho national on December 16, Poland's health ministry announced.
The case came two days after a Polish teenager who arrived on a flight from Warsaw became the first confirmed Omicron case in mainland China on December 14.
Two cases were detected in Romania in travellers who returned from South Africa on November 30, the country's health authorities confirmed on December 4. As of December 16, the number has risen up to 11 confirmed cases.
Russia confirmed its first two cases of the Omicron variant last week in two people from South Africa after 10 arrivals had tested positive for COVID-19, according to the Interfax news agency. As of December 13, the number is now 16 cases.
The laboratories of the Public Health Office (ÚVZ) in cooperation with the Science Park of Charles University in Bratislava confirmed the occurrence of the Omicron variant in the territory of the Slovak Republic on Friday December 10. Subjects were vaccinated with two doses of COVID-19 vaccine and all three showed only mild symptoms. Three cases have been confirmed so far as December 16.
Slovenia's health authorities confirmed it's first four Omicron cases on December 14. The country's National Institute of Public Health (NIJZ) has now said the total has risen to 10 cases after the discovery of two separate clusters linked to the new variant.
The first confirmed case of the Omicron variant has been detected at a Madrid hospital on November 29.
"The microbiology department of the Gregorio Marañon Hospital in Madrid has announced the first confirmation of the Omicron variant in Spain," the public institution said on Twitter, adding that it was "a traveller from South Africa" and that he was "doing well".
So far, the number of confirmed cases has risen to 51.
Spain continues to have one of the highest vaccination rates in Europe.
The first case was detected and confirmed by the Swedish National Public Health Agency on November 29. The person was an arrival from South Africa. The ECDC now says there are 51 confirmed cases in Sweden.
The surge of new COVID-19 cases forced the organisers of the Nobel Peace Prize awards ceremonies to pare down the event in Stockholm on December 6.
The Swiss health authorities announced on November 28 the discovery of a "first probable case" in a person returning from South Africa. Since then, the number of confirmed Omicron cases in Switzerland has risen to 128, according to GISAID's variant tracker.
Some 2,000 people - most of them children - were placed into a 10-day quarantine in the cantons of Geneva and Vaud on December 3 after two cases were detected at an international school.
The first six cases of the Omicron variant have been detected in Turkey, Health Minister Fahrettin Koca said on Saturday on state broadcaster TRT Haber.
Five of the cases were in the western city of Izmir and one in the largest city of Istanbul, according to the Anadolu press agency. "These six cases had no need for hospitalisation. The symptoms were very light. They were treated as outpatients and did not have any problems," Koca said.
According to data published by the UK Health Security Agency on December 16, the number of cases of the Omicron variant detected in the country now stood at 11,708 as of the evening of December 15.
"The spread of the Omicron variant of coronavirus appears to be doubling every two to three days," Prof Neil Ferguson, a member of the UK government’s Scientific Advisory Group for Emergencies (Sage) and head of the disease outbreak modelling group at Imperial College London, told BBC Radio 4 last week.
The total number of reported cases across Scotland is 663 cases. As for Wales, the total number of confirmed COVID-19 Omicron cases is 95. Cases in Northern Ireland stand at 210.
Prime minister Boris Johnson announced on December 13 that at least one person is now known to have died from the Omicron variant in the UK. This is the only known fatality attributed to Omicron worldwide.
"Sadly yes Omicron is producing hospitalisations and sadly at least one patient has been confirmed to have died from Omicron," he said during a visit to a vaccination clinic in London.
Earlier in the day, the government had raised the country’s official coronavirus threat level on December 12 over the Omicron variant after medical officers recommended raising the alert level from 3 to 4 on a 5-point scale.