Catalonia Faces Early Surge in Influenza Cases,Raising Public Health Concerns
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Catalonia is experiencing a significant and premature rise in influenza cases,with infections doubling in the last week of November and exceeding moderate levels of transmission,according to the latest report from the Facts System for the Surveillance of Infections in Catalonia (SIVIC).The concerning trend has prompted health officials to reassure the public about vaccine efficacy while closely monitoring the situation.
Flu Incidence Doubles in One Week
Data from November 24 to 30 reveal an influenza incidence rate of 164 cases per 100,000 inhabitants, a sharp increase from the 82 cases recorded the previous week. Experts note that this surge began five weeks ago, representing an unusually early start to the flu season.Currently,21% of analyzed samples are testing positive for influenza,with subtype A (H3N2) being the predominant strain.
During the analyzed week, a total of 11,122 flu cases were diagnosed in primary care – nearly double the 6,006 cases detected the week prior. The distribution of diagnoses across age groups shows a broad impact: 769 cases among children aged 0-4, 2,692 cases in the 5-14 age group, 4,462 cases among individuals aged 15-44, 1,885 cases in the 45-59 age group, 623 cases among those aged 60-69, 414 cases in the 70-79 age group, and 277 cases among individuals over 80.
Vaccine Protection Confirmed Against Circulating Variants
The Department of Health has moved to reassure the population, confirming that the two influenza subtypes currently circulating in Catalonia are covered by the vaccines administered during the 2024-2025 campaign. The recently detected variant K, now present on all continents, has not demonstrated unusually high severity in countries in the southern hemisphere that have already passed their epidemic peak.
“While this variant presents some divergence with respect to some reference vaccines, immunization will continue to offer effective protection against the most serious forms of the disease,” a senior official stated. Experts have observed no increase in the severity of cases in any country where the variant has become prevalent.
Respiratory Infections Overview: Flu, RSV, and COVID-19
The overall incidence of acute respiratory infections in Catalonia stands at 777 cases per 100,000 inhabitants, equivalent to 63,053 cases, reaching a baseline level of transmission. Rhinovirus currently leads with 39.3% positivity in samples, followed by influenza (21.1%) and Respiratory Syncytial Virus (RSV) at 6.9%.
Though, in the pediatric population, influenza A has become the dominant virus, present in 50% of analyzed samples. RSV, the primary cause of bronchiolitis, is also on the rise, with an incidence of 53 cases per 100,000 inhabitants – exceeding the baseline level after a four-week upward trend. COVID-19 transmission remains stable and low, with an incidence of 19 cases per 100,000 inhabitants.
Hospitalizations and Vaccine Coverage Rates
Hospital data indicates that all COVID-19 hospitalizations and the majority of flu-related hospitalizations during the analyzed week involved individuals over 60 years of age (20 out of 35 admitted). Currently, five people are in intensive care units (UCI) in Catalonia due to influenza. A significant 82% of those hospitalized with RSV are under the age of four.
Vaccine coverage rates vary by age group. Flu vaccine coverage reaches 64% in individuals over 80 and 50% in those aged 70-79. COVID-19 vaccine coverage is currently at 53% for those over 80 and 37% for the 70-79 age group. Among children aged 6-59 months,flu vaccine coverage is 36%.For RSV, accumulated coverage reaches 93.5% in babies born between April and September and 71.7% in those born between October and May 2024, resulting in a total coverage of 89.2% within this vulnerable population.
the ongoing situation underscores the importance of vaccination and continued vigilance as Catalonia navigates this early and concerning surge in respiratory illnesses.
