Influenza season 2014-2015in EU/EEA countries

R. Snacken, C. Adlhoch and E. Broberg

Stockholm, 10 June 2015

Intensity by country and by weekEU/EEA - 2014/15

2014W40

2014W41

2014W42

2014W43

2014W44

2014W45

2014W46

2014W47

2014W48

2014W49

2014W50

2014W51

2014W52

2015W01

2015W02

2015W03

2015W04

2015W05

2015W06

2015W07

2015W08

2015W09

2015W10

2015W11

2015W12

2015W13

2015W14

2015W15

2015W16

2015W17

2015W18

2015W19

2015W20

Austria

Belgium

Bulgaria

Croatia

Cyprus

Czech Republic

Denmark

England

Estonia

Finland

France

Germany

Greece

Hungary

Iceland

Ireland

Italy

Latvia

Lithuania

Luxembourg

Malta

Netherlands

Northern Ireland

Norway

Poland

Portugal

Romania

Scotland

Slovakia

Slovenia

Spain

Sweden

Wales Low

Medium

High

Very High

Unknown

First countries reporting medium intensity

Peak intensity of influenza activity EU/EEA - 2014/15

Low intensity was reported by:

CyprusDenmarkPoland

Influenza viruses (sub)-types by week EU/EEA - 2014/15

Positivity rate > 10% during 22 weeks

Number of specimens tested

for influenzaPositivity rate (%)

Influenza viruses (sub)-types by week EU/EEA - 2014/15

Week 52 Week 08Week 05

Week 04

Week 07

>10% positivity indicating influenza activity: 20-21 weeks

Week 44Peak week

Duration of positivity rate > 10%

Influenza-positive sentinel specimens by season and (sub-)type, EU/EEA 2008-2015

A(H3) B/Yam -A(H1)pdm09

A(H1)pdm09- A(H3)

A(H1)pdm09 –B/Vic

Variability in dominant and co-circulating virus types and subtypes

A(H3) –B/Yam

2010/11 2011/12 2012/13 2013/14 2014/152009/102008/09

A(H1)pdm09A(H3) –B

Dominant virus types season 2014/15, EU/EEA

Sentinel system

Dominant: >60%

RSV detections by season in 21 EU/EEA countries, 2013/14 and 2014/15

week

Number of detections

0

500

1000

1500

2000

2500

3000

40 41 42 43 44 45 46 47 48 49 50 51 52 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

RSV in EU 2013/14

2014/15

Genetic characterisation

Phylogenetic groupNumber of viruses

A(H1N1)pdm09 A/South Africa/3626/2013 (subgroup 6B)1 266

A(H1N1)pdm09 A/St Petersburg/27/2011 (group 6)1 6

A(H3N2) A/Texas/50/2012 (subgroup 3C.1)1 10

A(H3N2) A/Stockholm/1/2013 (subgroup 3C.2)1 2

A(H3N2) A/Hong Kong/5738/2014 (subgroup3C.2a)2 606

A(H3N2) A/Samara/73/2013 (subgroup 3C.3)1 300

A(H3N2) A/Switzerland/9715293/2013 (subgroup 3C.3a)2 65

B/Phuket/3073/2013 (Yamagata lineage clade 3) 364

B/Wisconsin/1/2010 (Yamagata lineage) 3

B/Brisbane/60/2008 (Victoria lineage) 9

1 Genetic group containing viruses with antigenic properties similar to the 2014–2015 vaccine virus2 Genetic group containing viruses with antigenic properties dissimilar to the 2014–2015 vaccine virus

Antiviral resistance, EU/EEA 2014/15

Virus type and subtype

Resistance to neuraminidase inhibitorsResistance to M2

blockers

Oseltamivir Zanamivir

Isolates

testedResistant %

Isolates

testedResistant %

Isolates

tested

Resistant

%

A(H3N2) 1 535 4 0.3 1 524 1 <0.1 244 244 100

A(H1N1)

pdm09566 2 0.4 560 0 0 84 84 100

B 515 0 0 510 0 0 NA1 NA NA

1 NA: Not applicable

ICU cases by (sub)type and age-groupin eight EU countries

Higher proportions of ICU admission in > 40 years and older

Number of ICU cases

Number of ICU cases

Number of influenza-related fatalities by (sub)type and age-group in hospitals (all wards)

Excess mortality among the elderly in 13 EU countries

Mølback K. et al. EuroSurv 2015; 20(11):pii=21065

excess mortality from all causes concomitant with influenza activity

Conclusions 2014-2015

• Start of the season, intensity and duration in primary care settings similar to previous seasons

• Large dominance of A(H3N2) viruses in almost all countries

• Increasing dominance of B viruses when circulating A(H3N2) viruses declined

• Antigenic and genetic drift of A(H3N2) resulting in very low vaccine effectiveness

• Very low percentage of A viruses showing a reduced susceptibility to Nis

• Most affected age-groups in hospitalised cases were infected by A(H3N2) virus

• Substantial excess mortality from all causes concomitant with influenza activity in 13 reporting EU countries

Thanks to all members of EISN

Thanks to WHO Regional Office Europe for the fruitful collaboration