Coronavirus latest news: Over 60 test positive after flying from South Africa to Amsterdam as fears rise over Omicron variant

The World Health Organization (WHO) has named the new coronavirus variant Omicron, skipping two letters of the Greek alphabet, Nu and Xi, to avoid giving what is perhaps the most dangerous variant yet the same name as President Xi Jinping, the leader of the Chinese Communist Party.

In May 2021, the World Health Organization announced that new variants of SARS-CoV-2 — the coronavirus causing the global pandemic — would be named after Greek letters, and not the country or locale in which they were first identified.

Beforehand, the only official labels were assigned by scientific databases and featured a letter followed by a string of numbers, such as B.1.1.7, P.1 and B.1.351.

As a result, these clunky names were replaced colloquially by the name of the place where they were first found, such as Kent, Brazil and South Africa.

But health officials were concerned about discrimination, prejudice and stigmatiation of people from these places and sought a naming system that avoided this.

Names of birds were suggested, but the WHO settled on the Greek alphabet as an inoffensive and easy to digest nomenclature system.

All pre-existing variants were retrospectively named in order of their emergence, while those that emerged later took up the next available letter in the alphabet.

And thus, the Kent variant became known as alpha, South African became eta, Brazilian became gamma and the Indian variant was rebadged as delta.

But aside from these well-known forms, there have been 9 others, stretching all the way down to Mu.

However, on Friday, the World Health Organization broke from this orderly system and called the 13th variant Omicron, the 15th letter of the alphabet.

Nu, the 13th letter of the alphabet, was likely skipped to avoid confusion about the new Nu variant, but no explanation has yet been given by the WHO.

It is also unclear if Nu and Xi will be used as variant names in the future.

Although epidemiologists say travel curbs may be too late to stop Omicron from circulating globally, many countries around the world - including the United States, Brazil, Canada and European Union nations - announced travel bans or restrictions on southern Africa on Friday.

On Saturday, Australia said it would ban non-citizens who have been in nine southern African countries from entering and will require supervised 14-day quarantines for Australian citizens and their dependents returning from there.

Japan said it would extend its tightened border controls to three more African countries after imposing curbs on travel from South Africa, Botswana, Eswatini, Zimbabwe, Namibia and Lesotho on Friday.

Sri Lanka, Thailand and Oman also announced travel curbs on southern African nations.

South Africa said Saturday it is being "punished" for detecting a new Covid-19 variant Omicron which the World Health Organization has termed a "variant of concern" and is more transmissible than the dominant Delta strain.

The decision by a number of countries around the world to ban flights from southern Africa following the discovery of the variant "is akin to punishing South Africa for its advanced genomic sequencing and the ability to detect new variants quicker," the foreign affairs ministry said in a statement.

The Czech Republic is examining a suspected case of the Omicron variant of the coronavirus detected in a person who spent time in Namibia, the National Institute of Public Health said on Saturday.

"A lab is checking a possible find of a positive specimen of the Omicron variant. We are awaiting confirmation or refutation of the case," spokesperson Stepanka Cechova said in an emailed statement.

EU health authorities have said the new strain poses a "high to very high risk" to the continent.

In the Netherlands all passengers who tested positive must stay in quarantine at the hotel for seven days if they show symptoms and for five days if they do not, the GGD said.

Passengers who tested negative, but who are remaining in the Netherlands, are expected to isolate at home.

"We understand that people are frustrated by this," the statement added, "people have just made a long trip with the idea that they will shortly be home," it said.

"Instead just after landing, they are confronted with a situation we have never before experienced in the Netherlands, namely that people have to be tested at Schiphol and are forced to wait until they get a result."

Those who do not live in the Netherlands can "continue their journey", it said.