Impact of COVID-19 on the seasonal influenza epidemic
Avian influenza reference laboratory meeting, 23 September 2020 Influenza season 2019/2020
Influenza activity started week 45/2019 and returned to baseline week 13/2020, earlier than previous seasons
Source: https://www.ecdc.europa.eu/en/publications-data/seasonal-influenza-annual-epidemiological-report-2019-2020 2 Influenza and COVID-19 until week 20/2020
SARS-CoV-2
• COVID-19 surveillance was implemented 27 January 2020 • First COVID-29 case in ECDC data base: 25 January 2020 (week 4/2020) • Very low circulation of influenza when SARS-CoV-2 started to circulate in EU/EEA and the UK • Influenza surveillance systems affected and disrupted by public health measures
Source: www.Flunewseurope.org; https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2020.25.9.2000178 3 Sentinel ILI/ARI, influenza and COVID-19 positivity, Germany and the Netherlands
ARI consultations
Influenza
RSV
COVID-19
Source: www.Flunewseurope.org; http://covid19-country-overviews.ecdc.europa.eu/#25_netherlands 4 Global influenza situation, data as of 11 September 2020
Data from 52 countries, areas or territories 17 August 2020 to 30 August 2020
Tested specimens 145 0681: 34 positive
19 (55%) type A 0 A(H1N1)pdm09 11 A(H3N2) 8 unsubtyped 15 (44%) type B. 3 B/Yamagata 5 B/Victoria 7 no lineage
Source: https://www.who.int/influenza/gisrs_laboratory/updates/summaryreport/en/; https://www.who.int/influenza/surveillance_monitoring/updates/latest_update_GIP_surveillance/en/ https://www.who.int/influenza/surveillance_monitoring/updates/2020_09_14_influenza_update_376.png?ua=1 5 No influenza in Australia 2020
Source: https://www1.health.gov.au/internet/main/publishing.nsf/Content/cda-surveil-ozflu- flucurr.htm/$File/Australian%20Influenza%20Surveillance%20Report%20No%2011%20-%2024%20August%20-%206%20September%202020.pdf 6 Influenza in Chile and South Africa, weeks 14-31 2017-2020
No influenza in the southern hemisphere
Source: https://www.cdc.gov/mmwr/volumes/69/wr/mm6937a6.htm?s_cid=mm6937a6_e&ACSTrackingID=DM38231&ACSTrackingLabel=This%20Week%20in%20MMWR 7 %20-%20Vol.%2069%2C%20September%2018%2C%202020&deliveryName=DM38231 Influenza surveillance, European Region season 2020/21
8 Influenza in the WHO European Region, weeks 21-34/2020
Sentinel Non-sentinel
42 995 tested; 24 positive: 812 tested 1 positive – influenza type B 1 A(H1N1)pdm09 2 A(H3N2) 10 Type A unsubtyped 11 Type B, no lineage Source: www.flunewseurope.org 9 COVID-19 cases in the EU/EEA and the UK, totals as of 17 September 2020
2 690 400 cases 100
185 355 deaths 80
Increasing trend across EU/EEA and the UK 60
40
Cases per 100 000 and and 000 100 per Cases 20 deaths per 1 000 000 population 000 000 1 per deaths 0 Jan Feb Mar Apr May Jun Jul Aug Sep
14-day death notification rate per 1 000 000 population 14-day cases notification rate per 100 000 population
The 14-day notification rates for COVID-19 are not directly comparable between countries due to differences in testing policies, testing capacity and surveillance systems at national level. ECDC therefore does not recommend using notification rates for comparison between countries. 10 Key messages for influenza surveillance 2020/21
Sentinel primary care influenza surveillance: Important to maintain existing ILI/ARI case definitions, where possible All ILI or ARI patients sampled and tested concurrently for influenza and SARS-CoV-2 Perform subtyping/lineage determination for all influenza positive specimens
Non-sentinel surveillance Prioritization for COVID-19 testing of all specimens from primary and secondary care; Parallel COVID-19 and influenza testing for people at risk to develop severe disease (elderly and underlying diseases) Test a random sample of all patients with ILI or ARI for influenza, based on clinical judgement and level of influenza circulation
11 Key messages for influenza surveillance 2020/21
Hospital influenza surveillance: Important to maintain existing SARI case definition, where possible Test all SARI cases for influenza and SARS-CoV-2 simultaneously, where possible
Laboratory considerations: Sequence a representative subset of influenza and SARS-CoV-2 viruses (date, geographical region, age, severity) Share influenza positive specimens with national influenza centres or reference laboratories At least 10% of the influenza viruses, or all when low circulation observed, characterised genetically and/or antigenically and tested (phenotypically and/or genotypically) for antiviral resistance
12 PRIMARY HOSPITAL CARE
SENTINEL NON-SENTINEL SENTINEL
ILI/ARI/SARI/COVID-19 ILI/ARI SARI compatible
All patients: All patients: All specimens: SARS-CoV-2 (priority) SARS-CoV-2 SARS-CoV-2 & Risk or selected groups/elderly: & Influenza 1. Influenza (multiplex with Influenza (multiplex) SARS-CoV-2) (multiplex) 2. Other respiratory viruses
13 Influenza surveillance during COVID-19
Joint ECDC WHO Europe influenza surveillance documents under development
14 Summary
- Surveillance systems for influenza disrupted and focus on COVID-19 - Only very few and sporadic influenza detections during the summer period, no influenza detections since week 32 in EU/EEA and the UK and overall WHO European Region - Globally influenza circulation is at historic low - Influenza surveillance important also during ongoing COVID-19 pandemic, systems need to be maintained for influenza vaccine composition 2021/22 season
15 Thank you for your attention
FluNewEurope – weekly joint ECDC WHO/Euro influenza bulletin www.flunewseurope.org
Country overview report http://covid19-country-overviews.ecdc.europa.eu/
COVID-19 dashboard https://qap.ecdc.europa.eu/public/extensions/covid-19/covid-19.html
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