deaths table 1. influenza surveillance indicators...table 1. influenza surveillance indicators...

Table 1. Influenza Surveillance Indicators

Surveillance Indicator

2018-19

Season

2017-18

Season

Prior 3-

Season

Average*

All influenza cases reported (rapid or PCR test) 9,655 20,854 11,313

Number of influenza-related outbreaks reported 25 119 56

Number of influenza-related deaths reported 77 343 166Influenza season is July 1 - June 30, Weeks 27-26. Total deaths reported in prior seasons: 343 in 2017-18, 87 in 2016-17, and 68 in 2015-16.

* Includes FYs 2015-16, 2016-17, and 2017-18.

April 30, 2014 Week #17, ending 4/26/14

The purpose of the Influenza Watch is to summarize influenza surveillance in San Diego County. This summary report reflects the 2018-19 season.

Season Highlights• The season was uncharacteristically long compared to previous seasons, with overall moderate

severity.• Influenza cases peaked in week 12 (March 17-23, 2019).• This was largely an influenza A season with A/H1-pdm09 predominant and a late showing of

A/H3N2 during weeks 9 to 13 (February 24-March 30, 2019).• Influenza B activity was very low, but consistent throughout the season.• Three pediatric influenza-associated deaths were reported. None had received the 2018-19

influenza vaccine. Thirty-five adults under the age of 65 years also died with influenza infection.

Epidemiology and Immunization Services Branchwww.sdepi.org (619) 692-8499 [email protected]

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9,655 Total Cases

20

18

-19

Seas

on

Su

mm

ary

77Deaths†

Pages 1-3: Season SummaryPages 4-9: Trend GraphsPage 9: Reporting Information

Contents

Virus Characteristics

PUBLIC HEALTH SERVICES

25Outbreaks*

* At least one case of laboratory-confirmed influenza in a setting experiencing two or more cases of influenza like illness (ILI) within a 72-hour period.

† Flu deaths less than 18 years of age are reportable to CDPH.

INFLUENZA WATCHCounty of San Diego

August 21, 2019Volume 18, Issue 31

2018-19 Season SummaryJuly 1, 2018 – June 30, 2019

Final Report

http://www.sdepi.org/

mailto:[email protected]

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of 9PUBLIC HEALTH SERVICES

0%

26%

44%

34%

100%

89%

97%94%

0

10

20

30

40

50

60

70

80

90

100

< 18 years 18-64 years 65+ years Total

Perc

ent

of D

eath

s

Figure 1. Percent of Influenza Deaths by Age Group, Vaccination Status, and Underlying Medical

Condition, 2018-19 Season.

Vaccinated Underlying Medical Condition* known to be vaccinated

N=3 N=35 N=39 N=77

Table 2. Influenza Cases Reported, 2018-19 SeasonPositive Test Type/Subtype Count Percent

Influenza A, subtype unknown 8,313 86.1%

Influenza A (H1N1)pdm09 507 5.3%Influenza A (H3) 184 1.9%

Influenza B, subtype unknown 540 5.6%

Influenza B/Yamagata 3 0.0%

Influenza B/Victoria 1 0.0%

Influenza, type unknown 107 1.1%

Total 9,655 100%



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Influenza Activity Indicator: The activity levels show how the emergency department visits for influenza-like illness as a percent of all visits (ED ILI%) compares to the mean of the ED ILI% from the pre-influenza season weeks (i.e., CDC disease weeks 27-39) observed from the prior five seasons.

There are 10 activity levels, classified as: Minimal (levels 1-3), Low (levels 4-5), Moderate (levels 6-7), and High (levels 8-10). An activity level of 1 corresponds to when the ED ILI% is below the mean; level 2 corresponds to when the ED ILI% is less than 1 standard deviation above the mean; level 3 corresponds to when the ED ILI% is more than 1 but less than 2 standard deviations above the mean, and so on, with an activity level of 10 corresponding to when the ED ILI% is at 8 or more standard deviations above the mean.











* Grouped by the earliest available of onset date, specimen collection date, diagnosis date, death date, or report date.







0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

2014-15 2015-16 2016-17 2017-18 2018-19

Perc

ent

Season

Figure 5. Proportion of Influenza Cases by Age Group and Season.

<1 1-9 yrs 10-19 yrs 20-39 yrs 40-59 yrs 60-79 yrs 80+ Missing

100

90

80

70

6

05

04

0

90

80

70

60

50

40

30

20

10

0



024

68101214

27 34 41 48 3 10 17 24 31 38 45 52 7 14 21 28 35 42 49 3 10 17 24 31 38 45 52 7 14 21 28 35 42 49 4 11 18 25 32 39 46 1 8 15 22Percent of Emergency Department Visits

Figure 5. Percent of San Diego County Emergency Department Visits for Influenza-like Illness by Week and FY Compared to 5-Year Baseline & Upper 95% Threshold Values (Serfling Method)

ILI% Baseline Upper 95% Threshold2012-13 2013-14 2014-15 2015-16 2016-17 2017-18





0

2

4

6

8

10

12

14

16

27344148 3 10172431384552 6 132027344148 3 10172431384552 7 142128354249 4 111825

Pe

rce

nt o

f E

me

rge

nc

y D

ep

art

men

t Vis

its

Figure 7. Percent of San Diego County Emergency Department Visits for Influenza-like Illness by Week and Season Compared to 5-Year

Baseline & Upper 95% Threshold Values (Serfling Method).

ILI% Baseline Upper 95% Threshold

2013-14 2014-15 2015-16 2016-17 2017-18 2018-19

0

2

4

6

8

10

12

14

16

18

27 41 3 17 31 45 6 20 34 48 10 24 38 52 14 28 42 4 18 32 46 8 22

Perc

ent o

f Dea

ths

Figure 8. Percent of San Diego County Deaths Registered with Pneumonia and/or Influenza by Week and Season Compared to Prior

5-Year Baseline & Upper 95% Threshold Values (Serfling Method).

%P&I Deaths Baseline Upper 95% Threshold

2013-14 2014-15 2015-16 2016-17 2017-18 2018-19

2013-14 2014-15 2015-16 2016-17 2017-18 2018-19



* Influenza vaccinations administered and entered into the San Diego Immunization Registry (SDIR)





0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,00027 28 29 30 31 32 33 34 35 36 37 38 39 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

July August September OctoberNovember December January February March April May June

Num

ber o

f Inf

luen

za V

acci

nes

CDC Week and Calendar Month

Figure 11. Number of Influenza Vaccinations Administered* by Week and Season.

2014-2015 2015-2016 2016-2017 2017-2018 2018-2019

https://www.sandiegoimmunizationregistry.org/sdir_home.htm



Influenza Reporting in San Diego County

Local providers are encouraged to report laboratory-positive influenza detections to the County Epidemiology Program by FAX (858) 715-6458. Please fax a Confidential Morbidity Report Form, or an Influenza Case Report Form, and/or a printed laboratory result. If known, please indicate if the patient was admitted to ICU and/or died, and/or is a resident of a congregate living facility.

Regarding sending influenza specimens to Public Health Laboratory (PHL) for confirmation, please use the updated PHL Test Request Form and contact PHL at (619) 692-8500 with any questions. Contact the Epidemiology Program by telephone (619) 692-8499 or email to [email protected] with questions regarding influenza data.

ResourcesCounty of San Diego Epidemiology Program website www.sdepi.orgCounty of San Diego 2017-18 Influenza Season Summary Current Week Influenza Watch Slide Deck – A slide presentation version of this report County of San Diego Immunization Program (SDIZ) www.sdiz.org

California Department of Public Health (CDPH) Influenza UpdateCenters for Disease Control and Prevention (CDC) Influenza Surveillance





0

2

4

6

8

10

12

14

16

18

27 28 29 30 31 32 33 34 35 36 37 38 39 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

July August September October November December January February March April May June

Perc

ent o

f ED

Vis

its

wit

h Ch

ief C

ompl

aint

CDC Week and Calendar Month

Figure 13. Percent of Emergency Department Visit Chief Complaints for Cough, Cold, Fever, or Respiratory

Symptoms by Week, 2018-19 Season.

Cough Cold Symptoms Fever Respiratory Symptoms

2018 2019

https://www.sandiegocounty.gov/content/dam/sdc/hhsa/programs/phs/documents/CMRa.pdf

http://www.sdcounty.ca.gov/hhsa/programs/phs/documents/FluCaseReportForm.pdf

https://www.sandiegocounty.gov/hhsa/programs/phs/phs_laboratory/index.html

https://www.sandiegocounty.gov/content/dam/sdc/hhsa/programs/phs/documents/SD_County_Test_Req.pdf



https://www.sandiegocounty.gov/content/dam/sdc/hhsa/programs/phs/documents/Season_Summary_2017-18.pdf

https://www.sandiegocounty.gov/content/dam/sdc/hhsa/programs/phs/documents/Influenza_SLIDEDECK_2018-19YTD.pdf

http://www.sdiz.org/

https://www.cdph.ca.gov/Programs/CID/DCDC/Pages/Immunization/Influenza.aspx

https://www.cdc.gov/flu/weekly/fluactivitysurv.htm



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