This is the flu that is already an epidemic in Spain

The end of the year is undoubtedly the classic time to have a cold or a bad flu due to the drop in temperatures what causes a lowering of defenseswhich is used by viruses to sneak into all citizens. This gives us the feeling that now everyone has a cold, but the reality is that Spain has officially entered an epidemic of flu.

There are reasons. And it is not a general feeling, but rather data from the Carlos III Health Institute confirms that the situation is radically different from that experienced last year. The wave of cases has started earlier, hits harder and brings with it a genetic novelty: the K variant.

Tripling figures. The most striking thing about the latest report of the Acute Respiratory Infection Surveillance System (SiVIRA) is not only that cases are increasing, but also the vertical speed at which they do so.

In the week of November 17 to 23the incidence in Primary Care reached 112.2 cases per 100,000 inhabitants, strongly breaking the baseline threshold established at 37 cases. To put it in context: in the same period of 2024, the incidence was only 12.8 cases. We are facing a scenario that practically triples the intensity at the beginning of the season compared to the previous year.

This is also added to a positivity rate in which the tests carried out are already close to 20%, which indicates that out of every five people who come with symptoms, one has confirmed flu.

A biological factor. Unlike previous seasons where the flu virus of the subtype reigned H1N1this year we are seeing a changing of the guard: the virus dominant is H3N2. And although it may seem somewhat minor, the reality is that the population has lower immunity against this subtype, since the body has not come into contact with it as frequently.

Added to this is the ECDC alert (European Center for Disease Control): The virus is not exactly the same as we knew. A mutation has been detected that has given rise to a new subclade, called Variant K.

What does variant K imply? Viruses mutate quite frequently, which is one of the reasons why a person who has been vaccinated can develop the disease. This is why this K variant can better evade the body’s defenses and nest more frequently.

But it does not indicate that it is more or less serious (as when we talked about COVID), but yes it is more contagious due to this immune evasion and that could explain the increase in cases in the general population.

Some vaccines… What don’t work? In recent weeks we have seen awareness campaigns for the vaccination of risk groups against the flu. But surely those who have been vaccinated are seeing how they are contagious and this raises many doubts about the usefulness of vaccines.

But to do this, you must understand that flu vaccination is done for a very specific type that is expected to be the majority of the season. The problem, like this, is that in the end the virus ‘surprises us’ with a mutation that ruins all our predictions, making the vaccines not as effective as we expected. Although it can also reduce the intensity of the symptoms.

The demographic map. The current epidemic that Spain is experiencing offers us a very clear photo of how it is moving. The citizens who are being infected the most right now are the smallest, that is, children from 1 to 4 years. These present a shooting rate of 428.5 cases per 100,000 inhabitants. A group that is the most affected, although also conditioned because parents go to the pediatrician at the slightest symptom, guaranteeing better case control.

But the real problem is in the hospital impact. Although right now we are not in saturation at the national level, in regions like Madrid Hospitalizations of people over 80 years of age have doubled in one week, going from 9.43 to 20.44 cases. A worrying fact in this case is the increase in cases of the most common complication: pneumonia.

In this way, the transmission vector is being the smallest, but the most affected are still the older people for whom the flu is a big problem. Even if they have been vaccinated.

The forecast. The increase in flu cases It has been advanced between 3 and 4 weeks compared to what we would expect in other years. In this way, if we normally expected the peak of infections at the end of January or beginning of February, this year everything is going to change radically.

In the case of Catalonia, the peak of cases is expected to occur between the second and third week of December, while other communities expect it during the Christmas holidays driven by family gatherings. In this way, as a positive point, whoever passes this flu first can avoid suffering its annoying symptoms in the middle of the Christmas holidays.

Use of the mask. We already know one of the systems to avoid contagion: the use of a mask. Last year there was great chaos to reach an agreement and impose its use, and this year it seems that a very similar scenario will follow.

There are already regions like Galicia and Aragón that have made a move recommending or imposing the use of masks in health centers and anticipating emergency saturation. And it makes a lot of sense that if we go to a health center we avoid infecting the people who are there, since they are probably older or immunocompromised and this can lead to a worsening of the disease.

Images | Towfiqu barbhuiya Matteo Fusco

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