Influenza Update:2010-2011 Season

Contributors: Lesley Brannan, Tony Aragon, Irene Brown

Carol M Davis, MSPH, CPHEpidemiologist

Emerging and Acute Infectious Diseases BranchTexas Department of State Health Service

Percentage of Visits Due to Influenza-Like IllnessReported by Texas Participants in ILINet, 2007-2011 Seasons

0%

2%

4%

6%

8%

10%

12%

14%

16%

18%

20%

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

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept

MMWR week

Pe

rce

nta

ge

of

Vis

its

Du

e t

o I

LI

2007-2008 2008-2009 2009-2010 2010-2011

Circulating Influenza Viruses

47%

21%

8%

24%

Flu A, not subtyped

Flu A, H3N2

Flu A, 2009 H1N1

Flu B

Texas: 2010-2011 influenza seasonthrough week 5

Vaccine Breakthrough

• DSHS has been receiving calls asking about potential influenza vaccine breakthrough this season– Voluntary reporting of suspected cases

• Influenza vaccine expectations– 70-90% in healthy adults <65– Less in certain subgroups (age/immunocompetence)

• Antigenic testing– All 29 Texas specimens tested so far were related to

a component of the 2010-2011 vaccine– 100% of H1N1, 99% of H3N2 and 93% of the Flu B

strains tested by the CDC were related to their respective components in the vaccine

Outbreaks

• 5 nursing home influenza outbreaks reported to DSHS in 2011– No deaths associated with these outbreaks

• CDC informal survey of state flu coordinators

• Recommend following CDC guidance www.cdc.gov/flu/professionals/infectioncontrol/– Report outbreaks (1 confirmed case)– Droplet precautions– Cohorting of ill / exposed; restrict movement– Provide antiviral treatment and chemoprophylaxis– Vaccinate unvaccinated individuals per

recommendations

Influenza Information

• Weekly DSHS report

www.texasflu.org

• Weekly CDC report

www.cdc.gov/flu/weekly/