Severity

A subset of Member States monitor severe disease related to influenza virus infection by surveillance of 1) hospitalized laboratory-confirmed influenza cases in ICUs (n=12), or other wards (n=8), or 2) severe acute respiratory infections (SARI; n=16).

The majority of severe cases reported this season have been due to influenza type B and have occurred in persons above the age of 15 years. In laboratory-confirmed influenza cases in ICU, slightly more cases were infected with influenza type A compared to type B viruses (n=4 937 and 4 448, respectively).

In laboratory-confirmed influenza cases reported in wards other than ICUs, influenza type B viruses were detected more frequently than influenza type A viruses (11 155 vs. 7 020), and more cases occurred among those older than 64 years compared with patients in the 15–64 years age group (10 319 vs. 5 550).

1.1) Hospitalized laboratory-confirmed influenza cases – Intensive care units (ICU)

Since week 40/2017, 12 countries have reported laboratory-confirmed influenza cases admitted to either all ICUs in the country or a set of sentinel ICUs (Table).

Numbers of reported hospitalized laboratory-confirmed influenza cases in ICUs remained low in week 20/2018, with only the United Kingdom reporting cases (n=7) which represents a further decrease in this country compared to recent weeks (16 and 19 in weeks 18/2018 and 19/2018, respectively).

Since week 40/2017, type A influenza viruses have been detected in 53% and type B in 47% of cases in ICUs. Of 1 920 subtyped influenza A viruses, 58% were A(H1N1)pdm09 and 42% A(H3N2). Of 5 802 cases with known age, 44% were 15–64 years old and 48% were aged 65 years and older.

Laboratory-confirmed ICU admitted cases* by country, cumulatively weeks 40/2017–20/2018

Country

Total Cases

A unsub.

A(H1N1) pdm09

A(H3N2)

B total

0-4

yrs

5-14

yrs

15-64

Yrs

>64

yrs

UNK

Czech Republic

308

43

66

6

193

12

10

130

156

0

Denmark

550

105

55

40

350

13

8

195

334

0

Finland

64

0

4

29

31

1

1

19

43

0

France

2 925

1 199

548

62

1 116

73

47

1 382

1 368

55

Ireland

169

43

16

29

81

18

16

62

73

0

Netherlands

15

5

0

0

10

0

0

8

7

0

Romania

55

1

26

1

27

4

2

25

24

0

Russian Federation

9

0

3

6

0

0

0

3

6

0

Spain

1 256

312

149

160

635

104

36

545

571

0

Sweden

447

136

9

14

288

10

19

185

233

0

Ukraine

59

1

1

2

55

16

20

23

0

0

United Kingdom

3 528

1 172

246

448

1 662

0

0

0

0

3 528

TOTAL

9 385

3 017

1 123

797

4 448

251

159

2 577

2 815

3 583

A unsub.= type A unsubtyped; *from either sentinel hospitals or all hospitals per country 


1.2) 
Hospitalized laboratory-confirmed influenza cases – other wards 

For week 20/2018, 3 cases were reported from other wards. Numbers of cases in other wards decreased in week 20/2018 compared to week 19/2018 (n=23).

Since week 40/2017, 8 countries have reported laboratory-confirmed hospitalized influenza cases in other wards (Table). The majority (61%) of these cases were infected by influenza type B viruses and 57% of all cases were in patients aged 65 years and older.

Laboratory-confirmed hospitalised cases in other wards* by country, cumulatively weeks 40/2017–20/2018

Country

Total Cases

A unsub.

A(H1N1) pdm09

A(H3N2)

B total

0-4

yrs

5-14

yrs

15-64

yrs

>64

yrs

UNK

Czech Republic

344

66

89

6

183

6

4

133

201

0

Denmark

7 989

1 251

507

703

5 528

429

285

2 662

4 613

0

Ireland

4 487

1 313

227

497

2 450

611

427

1 289

2 158

2

Romania

101

3

43

6

49

23

13

51

14

0

Russian Federation

388

0

59

197

132

94

34

206

54

0

Slovakia

4

2

1

0

1

0

0

4

0

0

Spain

4 603

1 248

255

523

2 577

247

52

1 030

3 274

0

Ukraine

259

10

6

8

235

35

44

175

5

0

TOTAL

18 175

3 893

1 187

1 940

11 155

1 445

859

5 550

10 319

2

A unsub.= type A unsubtyped; *from either sentinel hospitals or all hospitals per country 

 

2. SARI surveillance

Since week 40/2017, SARI cases have been reported by 16 countries, the majority being located in the eastern part of the Region.

For week 20/2018, 726 SARI cases were reported by 10 countries, most (41%) by Kazakhstan. In total, 101 specimens were tested for influenza viruses and 10% were positive.

For SARI cases testing positive for influenza virus since week 40/2017, type B viruses have been the most common (55%). Of the 787 influenza type A infected cases for which subtyping was performed, 60% were infected by A(H1N1)pdm09 viruses.

Mortality monitoring

Data from 24 EU/EEA Member States or regions reporting to the EuroMOMO project were received for week 20/2018 and included in pooled analyses. Mortality has been significantly elevated in many European countries over the past months, mainly affecting elderly people. However, mortality now appears be have returned to normal expected levels in all the participating countries.