The latest Health announcements have raised many doubts while waiting for the conclusions to come out this afternoon from the Interterritorial Health Council held this afternoon in Córdoba, the second in person since the pandemic began. The arrival of the Omicron variant has forced a review of the strategies. Health now establishes that quarantines are returned for all contacts of people who have tested positive for the new variant or who are suspected cases. An aspect that raises some doubts. For example, if you test positive for an antigen or a PCR, is there any change from what you had to do yesterday?

How do you know whether or not you are infected with Omicron?

You can only tell if I am infected with the Omicron variant if the virus is sequenced, something that is not usual. Therefore, the idea of ​​a suspected case of being infected with the new variant is worked on if the person has been in South Africa or some of the six high-risk countries of the southern cone.

The Early Detection Strategy document recognizes that “confirmation of the type of variant is not usually available at the time of diagnosis” and therefore indicates that “quarantine should also be applied to those cases in which there is suspicion.”

The five cases detected in Spain, two in Madrid, one in the Balearic Islands and the two suspects in Catalonia, are people who traveled to South Africa in recent weeks. At the moment, the change only affects people from these areas and their relatives or close contacts because no cases of local transmission have yet appeared. Now testing of virus samples is focusing on travelers.

What about direct contacts?

Until now, the vaccinated contacts of a positive with the Delta variant, which is the prevalent one, are exempt from quarantine. This was decided in June when the incidence of the pandemic had dropped a lot, before the fifth wave.

Now, the close contacts of an infected Ómicron, whether confirmed or suspected, will have to be isolated and quarantined even if they are vaccinated with the full schedule. They explain that it is a measure of protection, of early detection, of surveillance to try to avoid the spread of the new variant while waiting for it to be confirmed whether it is more contagious or not or if it eludes the effectiveness of vaccines.

The process to find out which is the variant, is it a common process, is it done with all cases or is it something exceptional?

It is done, but not all virus samples are sequenced. In Spain it is done between 5 and 10% a week, which is what the EU and WHO stipulate. With the advent of Omicron, more is being done in labs. It is an expensive procedure that requires staff and resources in hospitals. For example, in the microbiology laboratory of the Gregorio Marañón hospital in Madrid they have developed an ultra-fast technique that allows obtaining results in a few hours. The Balearic Islands have also done it.

Is it known how long the omicron variant has been circulating in our country?

There are only preliminary indications that come from Catalonia. His Health department has explained that it detected the Omicron variant in wastewater in that community in the last weeks of November. These indications are still pending to be confirmed. The Netherlands already confirmed that the Omicron variant was in Europe before the alert in South Africa.

How do you determine that a variant is predominant?

A variant is determined to be prevalent when the number of samples exceeds 50%. Now the predominant one in Spain is Delta since this summer.