In the forty-seventh week of 2025, the total incidence of acute respiratory infections in Italy is 8.96 cases per thousand attended, an increase compared to the previous week.
Monitoring is carried out by the Istituto Superiore di Sanità through RespiVirNet surveillance, which has renewed its operational protocol, available on the Ministry of Health website.
The incidence and the viral landscape
The value of 8.96 cases per thousand assisted represents the highest level recorded so far in the 2025-2026 season, signaling a typical progression of the autumn period. Last week the cases were 7.91. However, the new data collection methodology requires a cautious reading, since the broadening of the case definition includes a wider range of respiratory pathologies.
The co-circulation of different infections contributes to determining this value. In the community, the highest positivity rates were detected for influenza viruses, followed by Rhinoviruses and Adenoviruses. The current wave of ailments, in fact, cannot be traced back to a single pathogen, but to a set of pathogens affecting the population.
The most affected groups
Even in the hospital flow there was an increase in the positivity rate for influenza compared to the previous week. In this context, however, Rhinoviruses show the highest positivity rates, followed by influenza viruses and Adenoviruses. As regards SARS-CoV-2, the highest positivity rates are observed in the over 65 age group. This reminds us of the importance of the vaccination campaign against Covid-19 and influenza for the categories at greatest risk, such as people over 60 years of age.
As usual, the data confirms the greatest impact among the smallest. Here is the incidence by age group and per thousand assisted (‰):
- band 0-4 – 29.38‰;
- range 5-14 – 9.5‰;
- 15-24 – 9.05‰;
- 25-44 – 9.98‰;
- 45-64 – 7.42‰;
- 65+ – 5.04‰.
This data reflects the greater exposure of children in contexts such as nurseries and schools, where the transmission of respiratory infections occurs more easily.
The regions with the most sick people
The table shows the regional distribution of cases, highlighting significant territorial differences. Sardinia records the highest incidence (14.13‰), while Molise the lowest (4.44‰). For Calabria the data is not available in the weekly bulletin.
| Autonomous Region/Province | Total Cases | Incidence (per 1,000 patients) |
|---|---|---|
| Abruzzo | 1,185 | 10.41 |
| Basilicata | 78 | 6.46 |
| Campania | 95 | 9.68 |
| Emilia-Romagna | 1,457 | 8.81 |
| Friuli-Venezia Giulia | 271 | 8.26 |
| Lazio | 2,234 | 8.78 |
| Liguria | 530 | 6.95 |
| Lombardy | 4,374 | 9.35 |
| Marche | 246 | 8.98 |
| Molise | 75 | 4.44 |
| Piedmont | 1,137 | 9.62 |
| Autonomous Province of Bolzano | 69 | 5.97 |
| Autonomous Province of Trento | 73 | 4.77 |
| Puglia | 1,376 | 9.17 |
| Sardinia | 351 | 2.13pm |
| Sicily | 1,359 | 9.35 |
| Tuscany | 461 | 7.81 |
| Umbria | 73 | 4.87 |
| Aosta Valley | 50 | 6.02 |
| Veneto | 859 | 8.52 |
When will the peak be
Epidemiologists describe this season as “unusual” in terms of intensity and speed of spread, a trend favored by various factors. Such as the circulation of the new emerging variant (K) of the A/H3N2 influenza virus.
The World Health Organization predicts that the peak could arrive between the end of December and the beginning of January. The WHO statement reports that:
As of mid-November 2025, influenza test positivity in primary care in the European Region is at 17%. Based on previous trends, this season is expected to peak near 50% between late December and early January.
However, the anticipation of the flu season is not entirely new. The WHO observes similarities with the 2022-2023 season, one of the earliest of the last decade. Even in that case it was marked by a rapid increase in infections and a particularly strong spread of the A/H3N2 strain. This year, however, there is the presence of the K variant, making the trend less predictable.
