What's going around in Austria?

AGES integrates sentinel GP consultations, laboratory positivity, hospital and ICU admissions for severe acute respiratory infection, and virological characterisation at the National Reference Centre into a weekly respiratory-virus picture covering flu, SARS-CoV-2, and RSV. The same indicators feed ECDC ERVISS. On infectrisk.com we condense this picture into a qualitative low/moderate/high classification.

“Tripledemic” is a media label for the simultaneous winter circulation of flu, COVID-19, and RSV that was widely discussed from the 2022–2023 season onward. Austria saw clear co-circulation of all three pathogens that winter, with notable pressure on paediatric wards from RSV-driven bronchiolitis. Co-circulation has recurred each winter since, though the relative intensity of each pathogen varies.

The drivers are consistent across continental Europe. Many respiratory viruses remain stable longer in cold, dry indoor air, and heated indoor environments reduce humidity in ways that weaken airway defence. People mix indoors more during Austrian winters, schools amplify transmission among children, and end-of-year gatherings accelerate spread. Immunity to seasonal strains is also typically at its lowest as exposure rises.

AGES uses thresholds derived from historical surveillance data. Current indicators (sentinel consultations, laboratory positivity, hospitalisation signals) are compared against baselines from past non-epidemic weeks and against reference points from severe past seasons. When several indicators cross into elevated ranges at the same time, weekly bulletins flag activity as widespread. Austria's ERVISS contribution uses the same framework for cross-country comparison.

Austria's continental climate, school calendar, and indoor-contact patterns resemble Germany's and Switzerland's, and the three countries' winter respiratory curves typically move broadly in step. Because all report into ECDC ERVISS on the same schedule and methodology, the relative timing and intensity of their peaks is easy to read in the European dashboards. Lead–lag differences are usually a matter of weeks.