Week 6/2019 (4 -10 February 2019)
- Influenza activity is widespread in the European Region. Specimens collected from individuals presenting with ILI or ARI to sentinel primary health care sites yielded an influenza virus positivity rate of 53%, slightly lower than in the previous week (58%).
- Influenza type A virus detections dominated with A(H1N1)pdm09 viruses and A(H3N2) viruses co-circulating. Very few influenza B viruses were detected.
- 46% of specimens from patients hospitalized with severe acute repiratory infection (SARI) collected in week 6/2019 were positive for influenza virus, and all were type A.
- Pooled data from 24 Member States and areas reporting to the EuroMOMO project indicated excess mortality mostly among elderly aged 65 years and above, but also in adults in the age group of 15-64 years.
2018/19 season overview
Influenza activity in the European region, based on sentinel sampling, exceeded a positivity rate of 10% in week 49/2018 and has increased continuously into week 5/2019 after which it started to decrease. The positivity rate has exceeded 50% since week 3/2019.
Both influenza A virus subtypes are circulating widely, with co-circulation in some countries while others report dominance of either A(H1N1)pdm09 or A(H3N2) viruses.
Among hospitalized influenza virus-infected patients admitted to ICU wards, 40% of influenza A viruses were subtyped; of these 78% were A(H1N1)pdm09 virus. Among influenza virus-infected patients admitted to other wards, 28% of influenza A viruses were subtyped and 71% were A(H1N1)pdm09 virus.
Over 90% of influenza A viruses detected from SARI surveillance since week 40/2018 were subtyped and 81% were A(H1N1)pdm09 virus.
In general, current influenza vaccines tend to work better against influenza A(H1N1)pdm09 and influenza B viruses than against influenza A(H3N2) viruses and preliminary vaccine effectiveness estimates continue to support the use of vaccines. Early data suggests the vaccine are effective and estimates vary depending on the population studied and the proportions of circulating influenza A virus subtypes (e.g., higher VE in children). See data from Canada, Finland, Hong Kong, Sweden, and the United States.
Circulating viruses remain susceptible to neuraminidase inhibitors supporting early initiation of treatment and prophylactic use according to national guidelines.