The number of influenza cases at hospitals in Spain has doubled in a week, new figures show, surpassing any record from the past three years.
New data from the Carlos III Health Institute (ISCIII) reveal flu cases in primary care rose from 78.3 to 164.6 cases per 100,000 people in early December.
Last winter’s peak, reached at the end of January, stood at 141 cases. This year, Spain has already blown past that figure before Christmas.
The surge is hitting young children hardest. Among kids aged one to four, flu incidence has soared from 214 to 503 cases per 100,000. Those aged five to 19 follow closely behind.
Experts warned earlier this month that the peak would likely land during the Christmas holidays. With transmission accelerating, that prediction looks increasingly accurate.
The current rate also exceeds the highest point recorded during the 2023–24 season.
Even during the pandemic years, when Covid-19 distorted normal patterns, flu spikes were much gentler. In winter 2022-23, cases never went beyond 76 per 100,000. This season’s figures are already more than double that.
Hospital pressure rising
Hospital admissions have almost doubled in a week, increasing from four to 7.5 flu hospitalisations per 100,000 residents.
Since the start of the season, nearly one in five hospitalised flu patients has developed pneumonia, with ICU admissions at 4.4% and mortality at 4.6%.
Meanwhile, the positivity rate – the percentage of tests confirming flu – is climbing fast. In sentinel primary care centres, 41.6% of tests now detect influenza, up from 26.8% a week earlier. In hospitals, positivity has risen to 37.7%.
What’s driving the early surge?
The K variant of influenza A (H3N2), which differs from last season’s circulating strain, is believed to be fuelling the rapid spread – although specialists stress that it is not causing more severe illness.
The World Health Organisation echoed that view, saying current vaccines still offer protection against severe illness despite genetic drift in some circulating strains.
According to the ISCIII, the most common symptoms so far are:
- Fever (84.4%)
- Cough (84.3%)
- General malaise (77.9%)
- Nasal congestion (70.2%)
- Sore throat (61.5%)
Mask sales soar as regions tighten measures
Pharmacies have seen mask purchases surge by 385% in two weeks, and antigen test sales rise 150%, according to Cofares.
Catalonia and Murcia have already reinstated mandatory masks in all health centres and care homes as its flu cases doubled in one week.
Madrid, where incidence has jumped 145% to more than 275 cases per 100,000, is recommending masks in care homes, public transport and crowded indoor spaces. The Valencia region has also recorded a sharp rise, more than doubling its rate to 234 cases per 100,000 in early December. Andalucia has reported a threefold increase, reaching 33.5 cases per 100,000.
Health authorities are urging vaccination, mask use in high-risk settings and basic precautions such as ventilation and handwashing.

