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

Perc

enta

ge o

f Vis

its D

ue to

ILI

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

Circulating Influenza Viruses

47%

21%

8%

24%

Flu A, not subtypedFlu A, H3N2Flu A, 2009 H1N1Flu 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/