Is flu going around in Portugal?

Portuguese flu activity typically starts rising in December, peaks between December and February, and eases by March. The exact window varies year to year with the dominant influenza subtypes and residual population immunity. INSA, the Instituto Nacional de Saúde Doutor Ricardo Jorge, publishes weekly updates describing the season in qualitative phases rather than precise onset dates.

The Instituto Nacional de Saúde Doutor Ricardo Jorge classifies flu activity in qualitative intensity levels (baseline, low, medium, high, very high) drawing on the Médicos Sentinela GP network, sentinel-laboratory positivity, and hospital indicators. Each week's classification is compared with historical reference ranges. INSA also transmits Portuguese indicators to ECDC for inclusion in ERVISS.

Portugal's flu surveillance combines the Médicos Sentinela network, a long-established sentinel system of general practitioners reporting influenza-like illness, with sentinel-laboratory virology coordinated by INSA, including the National Reference Laboratory for Influenza and Other Respiratory Viruses. Hospital-admission data for severe acute respiratory infection complements the primary-care signal. Weekly bulletins summarise the picture and feed ECDC ERVISS.

Portugal offers free seasonal flu vaccination each autumn to priority groups including adults aged 60 and above, pregnant women, people with chronic conditions, residents of long-term-care facilities, and healthcare workers, administered through primary-care units and pharmacies under the Direção-Geral da Saúde programme. INSA publishes vaccination-coverage estimates alongside its weekly flu surveillance.

Because Portugal reports into ECDC ERVISS with harmonised indicators, its weekly flu classification is directly comparable with Spain, France, Italy, and the rest of the EU/EEA. Iberian flu curves often move broadly in step, with small lead–lag differences driven by school calendars and travel patterns. Portugal's mild Atlantic climate means peaks can sit slightly later or be less sharp than in colder continental countries.