Johannesburg: South Africa's top health federation on Sunday slammed the 18 nations which have imposed travel bans on the country on fears of the new potentially highly-transmissible variant of COVID-19, Omicron, saying the world must avoid such "knee-jerk reaction" if it wants "transparency" in the sharing of critical medical data.

The new COVID-19 variant B.1.1.529, first detected in South Africa, was on Friday designated as a Variant of Concern by the World Health Organisation (WHO), which named it Omicron.

The decision by 18 countries to ban flights to and from South Africa was premature, as there is still not enough information on how dangerous the variant might be, Angelique Coetzee, Chairman of South African Medical Association (SAMA) said.

Coetzee also defended the decision to announce the findings, pointing out that South Africa should be lauded and not vilified for this.

"My suspicion is that because our scientists are very alert and doing a lot of sequencing in the background, maybe those European countries missed it because of the symptoms," Coetzee told the TV news channel Newzroom Afrika.

The UK announced on Thursday that all flights to and from South Africa and five neighbouring countries would be banned from Friday following an announcement that the new Omicron variant of COVID-19 had been detected in South Africa.

Many other European countries followed suit, most of them indicating that only their own citizens would be allowed back, subject to a quarantine period. Many other countries have now started to severely regulate or ban flights completely from the African nation.

Coetzee said, The symptoms are not the same as the Delta (variant). It is very similar to the Beta (variant) and you can easily miss the symptoms. I think what happened with us in South Africa as clinicians is the fact that we have merely seen virtually maybe one or two patients per week in the past eight to ten weeks on COVID-related symptoms.

When we all of a sudden saw young people, especially men, coming in complaining of extreme fatigue, body aches and pains, headaches and a bit of a scratchy throat, we then started to test again and we found them positive."

Coetzee said they decided to alert the Advisory Council on COVID-19 that there were new symptoms that were not matching with the signs of the Delta variant.

"We were lucky that we had a break in between and saw the new symptoms. But now we are being (seen as) the villains. It's not right. It should never happen like this. If the world wants transparency, they would need to deal much better with this type of data that has been made available, Coetzee said.

The Omicron variant has also been detected in Israel, Hong Kong, Belgium Germany, Italy, the Czech Republic and Australia.

Coetzee said, "Everybody is going on about the science behind the variants, but very little is ever communicated around the symptoms. So, if you as a country want to protect your own people, look at what is happening.

"Alert your people. Say that there might be possibility of this going forward. But there's no know way you can just have this kind of knee-jerk reaction and say now you are safe."

Citing the high number of infections in the UK and the Netherlands, Coetzee said the new variant was already likely there without authorities being aware of it.

The new variant is considered potentially more dangerous because it has around twice as many mutations as Delta, but experts say how much of a concern is still under investigation.

Coetzee's comments come as South Africans were eagerly waiting for what President Cyril Ramaphosa is expected to announce later on Sunday after a meeting with the Corona Command Council.

While scientists are calling for tightening the current Level One of a five-level lockdown strategy, the business community has warned against it.

Meanwhile, the South African national carrier's plans to dispatch a large aircraft to take passengers back to Mauritius and return others to South Africa were scuppered by an announcement from the Mauritian government banning incoming passengers.

It is with great sadness that we have just received notification from the Mauritian government imposing further restrictions prohibiting all incoming travellers arriving from South Africa to the island, South African Airways (SAA) CEO Thomas Kgokolo said in an online video message to customers on Sunday morning.

As a result, SAA has now cancelled flight SA190 from Johannesburg to Mauritius on Sunday (afternoon). This fight will now operate to Mauritius as a ferry to pick up customers out of Mauritius, he said.

Kgokolo assured passengers stranded across the globe that SAA remained committed to assisting them.

We have made flexible changes to accommodate all our customers who have been affected by all these unforeseen travel restrictions, Kgokolo said. "Outbound passengers who are now unable to travel would be allowed one change to their future travel plans".

Along with South Africa, its neighbouring states -- Botswana, Namibia, Mozambique, Zimbabwe, Lesotho, Eswatini, Malawi, Zambia and Angola -- have also been slapped with travel bans, crippling their economies which are largely reliant on tourism.