Unusually early rise in ARIs as influenza reaches epidemic threshold

The week 48 surveillance report (24–30 November) shows acute respiratory infections (ARI) at 223.26 cases per 100,000 inhabitants and influenza at 26.41 cases per 100,000 — both above their respective epidemic thresholds. The influenza incidence exceeds the epidemic threshold of 20.47 cases per 100,000.

By age, ARI incidence is highest among newborns and infants under one year. Influenza activity is concentrated in children aged 1–4 and in young people aged 15–24. SARS‑CoV‑2 circulation is reported to be declining across all age groups.

Laboratory testing found 12.5% of samples positive for respiratory viruses. Of those detections, 36% were Rhinovirus/Enterovirus, 32% were influenza A, 24% were respiratory syncytial virus (RSV) and 8% were Adenovirus. Surveillance notes that RSV detection remains relatively low but is increasing gradually.

Health authorities and European surveillance platforms highlight that ARIs are rising rapidly and “unusually early” compared with previous seasons, while influenza has shown a more moderate increase. The pattern — an earlier-than-usual rise in other acute respiratory infections alongside the start of the influenza epidemic — will continue to be monitored through ongoing surveillance and laboratory data.