Primary care data
All countries reported low activity of respiratory infections, based on syndromic surveillance data for influenza-like illness (ILI) or acute respiratory infection (ARI).
For week 48/2017, low intensity of influenza activity was inferred by all of the 42 countries reporting on this indicator.
No geographic spread of influenza was reported by 16 of the 42 countries reporting on this indicator; 23 countries reported sporadic cases, 2 reported local geographic spread and 1 country (Turkey) reported regional spread.
Viruses detected in sentinel-source specimens (ILI and ARI)
For week 48/2017, 95 (8.8%) of 1 079 sentinel specimens tested positive for influenza viruses: 20 A(H1N1)pdm09, 7 A(H3N2), 9 un-subtyped A viruses, 11 B/Yamagata, 1 B/Victoria lineage and 47 B viruses not ascribed to a lineage. 28% of all influenza B virus detections are reported from Spain. This is the second consecutive week with more type B virus detections than type A viruses. While the majority of B viruses were not ascribed to a lineage, of those that were, 92% were B/Yamagata and of the type A viruses subtyped, 74% were influenza A(H1N1)pdm09 viruses.
Of 21 countries across the region that each tested at least 10 sentinel specimens in week 48, 9 countries reported detection proportions of at least 10%: Armenia (15%), France (25%), Hungary (13%), Israel (19%), Italy (10%), Poland (10%), Spain (13%), Switzerland (13%) and the United Kingdom (Scotland) (41%).
Since week 40/2017, more influenza type B than A viruses have been detected. Of 109 subtyped A viruses, 52% were A(H1N1)pdm09. The majority of B viruses were reported without lineage and of 53 influenza B viruses ascribed to a lineage, 51 (96%) were B/Yamagata.