This year the flu has advanced and reached Spain with force, where it has already arrived Epidemic threshold. Over the past week, health centers have seen a slight increase in influenza infection cases 112.2 cases per 100,000 inhabitants, a figure far from the 12.8 cases per 100,000 inhabitants that existed in the same period last year.
This is confirmed by the data, which comes from the latest epidemiological bulletin of the Carlos III Health Institute Flu screening This fall. that it “Atypical” behavior.The Spanish Society of Family and Community Medicine (semFYC) says in a statement.
Among the reasons that explain this rebound is the emergence of A H3N2 virus variant, subclass KIt is more contagious, and has been spreading since April or May in various European Union countries, which “makes it logical to believe that it could reach Spain,” says the spokesman for the Infectious Diseases Working Group, José María Molero.
Although the increase in influenza cases in consultations in Spain shows a In advance for about a month At the onset of influenza activity, this is not yet reflected in hospitalization data.
However, doctors They don’t let their guard down When observing the behavior of influenza epidemics in other countries e.g Japanwhich was also developed and later resulted in a higher volume of hospitalizations after the presence of subtype K of the H3N2 influenza virus was confirmed.
In Spain, there is no official confirmation at the moment “due to the lack of sequence data,” says semFYC, but everything indicates that if the circulating variant is this one, “we will find ourselves facing A more transmissible virus“, although not more dangerous.
“Although the virus is not more virulent, it is capable of being Cause more admissions and complications Because it affects people who were protected by the vaccine and were not as protected in other years when there were fewer antigenic changes,” Molero says.
In this scenario, the communities have already taken some measures specific to their territories, such as recommending or enforcing the mask in health centres, while the Ministry of Health hopes to standardize measures with the autonomous communities in the Public Health Committee that will be held next Wednesday, thus creating Common protocol Against respiratory viruses.
How does the vaccine affect the new variant?
Getting vaccinated is still essential as a preventative tool against influenza, despite the flu vaccine this season It was designed before the advent of the K subclassso the protective effects could be less. “This is an antigenic change in the hemagglutinin, the outer protein of the virus that allows it to get into respiratory cells,” Molero says. “When the immune system does not recognize this structure well, the virus penetrates more easily. This makes it more invasive and more transmissible, even in people who have been vaccinated, because this year’s vaccine contains the H3N2 variant with a slightly different composition.” This would explain, if subcategory K is confirmed to be dominant in Spain, this progress in the spread of the virus and the increase in infection even among vaccinated people.
“Although protection against subgroup K may be lower, the vaccine It continues to prevent serious infections As for the rest of the viruses that are included in its composition,” explains the spokesman for the Infectious Diseases Working Group. In addition, we must remember that the current vaccine also Protects against H3N2 variants Without these changes, compared to Virus A(H1N1) and vs B virusthey are all likely to be traded in our country, according to semFYC.
This is seen by the scientific community “It is very likely” that subcategory K “began to spread in Spain.” It calls for the implementation of several lines of action “to promote vaccination among people at risk, accelerate the sequencing of influenza viruses, prepare health services to increase consultations and admissions, and inform the population of the importance of maintaining prevention measures.”
For its part, the European Center for Disease Prevention and Control (ECDC) has prepared a list of names Recommendations To do in this influenza epidemic situation:
- People most at risk of serious illness should be vaccinated without delay.
- Early treatment of infected individuals with influenza antivirals is essential to reduce the likelihood of complications and disease progression in populations most at risk for serious illness.
- Antiviral prophylaxis should be considered in outbreaks detected in closed settings, such as nursing homes, regardless of vaccination status.
- Hospitals and healthcare centers must review their preparedness plans and improve their prevention and control practices to relieve pressure on the health system, such as the use of masks.
- Countries should provide personalized information to populations on how to reduce transmission and impact of severe disease through clear messages on vaccination, hand hygiene and respiratory protocol.
Symptoms detected
According to the latest bulletin of the Carlos III Health Institute,… The main symptoms of influenza Which are recorded this season in Spain coughWhich represents 81.6% of those infected, in addition to fever (80.3%); General malaise (74.5%) and Nasal congestion (72.8%). The following are sore throat (60.1%), headache (41%), and muscle pain (40%).
Currently, the latest report from the Carlos III Health Institute shows that the majority of cases are occurring in the country Children from 1 to 4 years (which reaches a figure of 428.5), followed by the group 5-19 years (304) and those under 1 (267.2).