What's going around in Iceland?

Landlæknir and Landspítali integrate primary-care consultations, laboratory positivity, hospital and ICU admissions for severe acute respiratory infection, and virological characterisation at the hospital reference laboratory 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.

Iceland has only around 400,000 residents, so absolute case counts are much smaller than in larger European countries. Individual weeks can therefore carry more random noise: a handful of extra cases can shift a rate noticeably. For that reason, Landlæknir and infectrisk.com place more weight on multi-week trends than on single-week data points when judging whether activity is rising, falling, or stable.

“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. Iceland saw clear co-circulation of all three pathogens that winter, with notable pressure on paediatric wards at Landspítali from RSV-driven bronchiolitis. Co-circulation has recurred each winter since, though the relative intensity of each pathogen varies.

Landlæknir uses thresholds derived from historical reference data. Current indicators (primary-care consultations, laboratory positivity, hospitalisation signals) are compared against baselines from past non-epidemic weeks and against reference points from severe past seasons. Because the population is small, several indicators rising together across multiple weeks is a stronger signal than any one week's reading. Iceland's ERVISS contribution uses the same framework for cross-country comparison.

Iceland's Nordic and Atlantic climate, primary-care structure, and school calendar share much with Norway and Denmark, 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. Iceland's smaller sample size makes Nordic cross-comparison a useful sanity check when interpreting noisy weekly signals.