National Center for Immunization & Respiratory Diseases

Influenza Season Update

Lynnette Brammer, MPH

National Vaccine Advisory CommitteeFebruary 8, 2018

Influenza Virologic Surveillance, 2017-2018 Season

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201740201740201740201740201740201740201740

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201801201801201801201801201801201801201801

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201810201810201810201810201810201810201810

201811201811201811201811201811201811201811

201812201812201812201812201812201812201812

201813201813201813201813201813201813201813

201814201814201814201814201814201814201814

201815201815201815201815201815201815201815

201816201816201816201816201816201816201816

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201819201819201819201819201819201819201819

201820201820201820201820201820201820201820

Influenza Positive Tests Reported to CDC by U.S. Public Health Laboratories, National Summary, 2017-2018 Season

B (Yamagata Lineage)

B (Victoria Lineage)

B (lineage not performed)

H3N2v

A (H3N2)

A (H1N1)pdm09

A (subtyping not performed)

Week

Number of Positive Specimens

16

0

5

1

121

13

3

11

4

6

0

142

14

1

11

1

2

0

173

14

0

20

1

8

0

173

26

4

32

3

17

0

240

23

2

30

4

12

0

314

28

1

59

4

34

0

398

56

2

58

5

12

0

482

41

0

95

8

27

1

752

61

10

86

14

38

0

960

68

7

157

30

42

0

1343

127

14

203

35

96

0

2197

209

39

302

28

104

0

2530

245

23

369

32

168

0

2761

254

32

348

27

128

0

2681

273

74

294

19

119

0

1784

255

62

201

13

103

0

1017

189

74

Sheet1

A (subtyping not performed)2009 H1N1B (lineage not performed)A (H3N2)H3N2vB VicB Yam

20174031351211016

20174111461420411

20174201421730111

20174342681730120

201744223172400332

201745128123140430

201746256343980459

201747041124820558

2017481061277521895

2017497683896001486

20175014127421343030157

20175139209962197035203

201752232451042530028302

201801322541682761032369

201802742731282681027348

201803622551191784019294

201804741891031017013201

201805

201806

201807

201808

201809

201810

201811

201812

201813

201814

201815

201816

201817

201818

201819

201820

Sequence Results, by Genetic HA Clade/Subclade, of Specimens Submitted to CDC by U.S. Public Health Laboratories, Cumulative,

2017-2018 Season

Influenza Positive Specimens Reported by U.S. Public Health Laboratories,

Cumulative, 2017-2018 season

18068

1896

348228

2292

921

Influenza A(H3N2)Influenza A(H1N1)pdm09Influenza A(subtype unknown)Influenza B VictoriaInfluenza B YamagataInfluenza B (lineage not determined)

Chart1

3C.2a

3C.3a

3C.2a1

Total

Influenza A(H3N2)

554

10

104

Sheet1

Total

3C.2a554

3C.3a10

3C.2a1104

Chart1

6B.1

6B

Total

Influenza A(H1N1)pdm09

253

0

Sheet1

Total

6B.1253

6B0

Chart1

Y3

Total

Influenza B Yamagata

317

Sheet1

Total

Y3317

Chart1

V1A

V1A-2Del

Total

Influenza B Victoria

28

23

Sheet1

Total

V1A28

V1A-2Del23

Chart1

Influenza A(H3N2)

Influenza A(H1N1)pdm09

Influenza A(subtype unknown)

Influenza B Victoria

Influenza B Yamagata

Influenza B (lineage not determined)

Count

18068

1896

348

228

2292

921

Sheet1

Count

Influenza A(H3N2)18068

Influenza A(H1N1)pdm091896

Influenza A(subtype unknown)348

Influenza B Victoria228

Influenza B Yamagata2292

Influenza B (lineage not determined)921

Outpatient Visits for Influenza–like Illness

7.1%

Geographic Spread of Influenza

Laboratory Confirmed Influenza-Associated Hospitalizations, FluSurvNet, 2017-18

Overall: 51.4≥65: 226.8 50-64: 54 18-49: 15.9 5-17: 8.3 0-4: 33.3

Influenza-Associated Mortality

Summary

• Influenza A(H3N2) viruses have predominated• ILI activity is the highest we’ve seen since 2009• Final severity can’t be determined until the end of the

season, but for adults, hospitalization rates and mortality could be similar to or exceed those seen during the 2014-15 season

For more information, contact CDC1-800-CDC-INFO (232-4636)TTY: 1-888-232-6348 www.cdc.gov

The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.

Influenza Season UpdateInfluenza Virologic Surveillance, 2017-2018 Season�Slide Number 3Outpatient Visits for Influenza–like IllnessGeographic Spread of InfluenzaLaboratory Confirmed Influenza-Associated Hospitalizations, FluSurvNet, 2017-18Influenza-Associated MortalitySummarySlide Number 9