10/16/2019

1

Influenza Surveillance in Texas

Andrea Salinas, MPH, CPH, CIC

October 23, 2019

Objectives

• List influenza surveillance activities performed in Texas

• Describe current and past flu season trends

• Recognize the strengths and limitations of current surveillance practices

2

1 2

10/16/2019

2

Influenza Surveillance

• The Influenza Surveillance System is a multi-component surveillance network with local, regional, state, and national activities

• Data collection is based on a reporting week that starts on Sunday and ends on Saturday of each week.

• CDC MMWR Weeks

• October 23 = Week 43

• Flu surveillance season: week 40 to week 20

3

Goals of Influenza Surveillance

• Find out when and where influenza activity is occurring

• Determine what type of influenza viruses are circulating

• Detect changes in the influenza virus

• Track influenza-related illness

• Measure the impact influenza is having on deaths

4

3 4

10/16/2019

3

Texas Influenza Surveillance Activities

• Morbidity

• ILINet: Outpatient ILI

• Outbreaks

• Syndromic

• Mortality

• Influenza-associated pediatric deaths

• Death certificate data

• Viral

• NREVSS: Hospital laboratory reporting

• Public Health Lab testing

5

What’s Reportable in Texas?

1.Novel influenza A cases in humans

2.Influenza-associated pediatric deaths

3.Outbreaks (influenza, ILI, etc.)

6

5 6

10/16/2019

4

Key Term: ILI

• ILI = Influenza-like Illness

• Fever > 100o F, and:

• Cough and/or

• Sore throat

• In the absence of another known cause other than influenza

7

Morbidity

ILINet

• US Outpatient ILI Surveillance Network

• Collects aggregate counts of all patients seen and the count of patients with ILI by age group

• Data is reported weekly

• Participation is voluntary2018-2019 influenza season: 114 regularly reporting Texas facilities

8

7 8

10/16/2019

5

9

ILINet

10

Percentage of Visits Due to ILI Reported by TX ILINet Providers, 2015-2016 to 2018-2019 Seasons

9 10

10/16/2019

6

Morbidity

Outbreaks

• Outbreak reporting is required by lawBoth lab-confirmed influenza and ILI outbreaks

• 183 reported outbreaks in Texas during the 2018-2019 influenza season

11

Morbidity

Syndromic Surveillance

• Selected elements of the electronic health record sent to syndromic surveillance system from hospitals, urgent cares, free-standing ERs, etc.

• Symptoms and diagnoses get categorized into “syndromes”

• Data is analyzed for trends and abnormalities

12

11 12

10/16/2019

7

13

Mortality

Influenza-associated Pediatric Deaths

• A death in a child under 18 years of age resulting from a clinically compatible illness that was confirmed to be influenza by an appropriate laboratory or rapid diagnostic test

• 2018 – 2019 influenza season statistics• 17 deaths reported• 64.7%* known to be unvaccinated• 35.3% had no known underlying risk

factors

*likely much higher due to 23.5% of cases with unknown vaccination status

14

13 14

10/16/2019

8

15

Influenza-associated Pediatric Mortality

16

15 16

10/16/2019

9

Mortality

Pneumonia & Influenza Mortality

• Data obtained from death certificates

• Underlying or contributing cause(s) of death is reported as pneumonia or influenza

17

Age Category (years)

Number of P&I Deaths*

Mortality Rate (per 100,000)

0 - 4 42 1.96

5 - 17 40 0.72

18 - 49 642 4.84

50 - 64 1702 32.81

65 + 7594 198.0

Overall 10020 33.46

HSRNumber of

P&I Deaths*Mortality Rate (per 100,000)

1 369 39.62

2/3 2926 33.77

4/5N 787 48.02

6/5S 2375 30.29

7 1114 30.36

8 1087 35.16

9/10 508 31.76

11 848 33.75

Unknown <10 N/A

Overall 10020 33.46

*NOTE: Data are provisional and subject to

change, errors, and duplicates

Viral Surveillance

NREVSS

• National Respiratory and Enteric Virus Surveillance System

• Healthcare providers voluntarily report total number of respiratory specimens tested and number of positivesData is reported weekly

• Captures influenza test results, along with: Adenovirus, human metapneumovirus, parainfluenza, rhinovirus, enterovirus, RSV, and coronavirus

18

17 18

10/16/2019

10

19

Viral Surveillance

Laboratory Surveillance

• Specimens are voluntarily sent to the DSHS lab or Texas LRNs by healthcare providers

• Specimens get tested by PCR Identification and subtyping

• A subset of submitted specimens are sent every two weeks to CDC for further testing

20

19 20

10/16/2019

11

Laboratory Surveillance

1.Numbered list

a.Second level

i. Third level

21

Influenza Surveillance

• Strengths

• Multiple data sources

• Many electronic surveillance systems available

• Weaknesses

• Most reporting is voluntary

• ILI vs Influenza

22

21 22

10/16/2019

12

Thank youAndrea Salinas, MPH, CPH, CIC

Andrea.Salinas@dshs.texas.gov

FluTexas@dshs.texas.gov

23

23