Week 20/2020 (11 – 17 May 2020)
- This is the last weekly bulletin for the 2019/20 season. The first inter-seasonal bulletin will be published on 26 June 2020.
- For the Region overall, influenza activity has sharply declined: all but 5 Member States and areas reporting on the intensity indicator registered baseline levels of intensity. All but 5 Member States reporting on geographic spread registered no influenza activity.
- Of 42 specimens, from patients presenting with ILI or ARI symptoms to sentinel primary healthcare sites, that were tested for influenza in week 20/2020, only 1 was positive for an influenza virus.
- The novel coronavirus disease 2019 (COVID-19) pandemic in the Region is affecting healthcare presentations and testing capacities in Member States, which has a negative impact on reporting of influenza epidemiologic and virologic data. Therefore, the data we present, notably in terms of seasonal patterns, must be interpreted with caution.
2019/20 season overview
- For the Region as a whole, influenza activity commenced earlier than in recent years and, based on sentinel sampling, first exceeded a positivity rate of 10% in week 47/2019.
- The influenza season for the Region as a whole peaked in week 05/2020, reaching a maximum positivity rate of 55%. The peak phase with positivity levels above 50% lasted for just two weeks, 05/2020 and 06/2020, but reporting in subsequent weeks has been adversely affected by Member State responses to the COVID-19 pandemic. In the previous influenza season, the influenza positivity rate exceeded 50% for six weeks.
- Both influenza types A and B co-circulated in the Region. Of the influenza A viruses, both influenza A(H1N1)pdm09 and A(H3N2) co-circulated. Of the circulating B viruses, the vast majority belonged to the B/Victoria lineage.
- The percentage of specimens testing positive for an influenza virus from patients who presented with ILI or ARI to sentinel primary healthcare sites dropped below 10% in week 13/2020, where it has since remained. In the 2018/2019 season, the positivity rate first dropped below 10% in week 17/2019.
- The majority of analysed viruses were susceptible to neuraminidase inhibitors supporting early treatment or prophylactic use according to national guidelines.
- Interim estimates of 2019–2020 seasonal influenza vaccine effectiveness in the northern hemisphere are available. Vaccination remains the best possible method for prevention of influenza and/or reducing the risk of serious complications.
- WHO has published recommendations for the composition of influenza vaccines to be used in the 2020–2021 northern hemisphere season. Based on these recommendations, the influenza A(H1N1)pdm09, A(H3N2) and B/Victoria-lineage virus components should be updated for the 2020–2021 influenza vaccine.
The World Health Organization categorized COVID-19 as a pandemic on 11 March 2020. For more information about the situation in the WHO European Region visit: