Presented to the Pierce County Central Safety Committee, March 2, 2017

1. Matthew Rollosson, RN, MPH&TM
Tacoma-Pierce County Health Department
2 March 2017

2. South China Morning Post, February 26, 2017

3.  Viral infection of the cells that line the respiratory
tract
 Common symptoms:
◦ Fever
◦ Chills, body aches, headache
◦ Dry cough, runny nose, sore throat
 Not to be confused with “stomach flu”
◦ Nausea and vomiting may accompany influenza,
but are not primary symptoms
Treanor, 2015

4.  Sudden onset
 Fever usually lasts about 3 days
 1 – 2 day incubation
 Contagious period:
◦ Just before onset of symptoms
◦ Virus usually not detected after 5 days
 Transmitted by respiratory droplets
Treanor, 2015

5.  Attack rate: 10% to 20% in unvaccinated
populations
◦ As high as 40% to 50%
 Average:
◦ 3 to 4 days in bed
◦ 5 to 6 days restricted activity
◦ 3 days school/work lost
Treanor, 2015

6.  Increased risk of complications and death from
influenza:
◦ Age
◦ Chronic heart disease
◦ Chronic lung disease
◦ Diabetes
◦ Immune compromise
◦ Obesity
◦ Pregnancy/postpartum

7. 0
20
40
60
80
100
120
Numberofhospitalizations
CDC Week
2013-14
2014-15
2015-16
2016-17

8. 0
5
10
15
20
25
30
35
Numberofdeaths
Month reported
2013-14
2014-15
2015-16
2016-17

9.  Not living cells
 Must infect cells to replicate

10.  Hemagglutinin: molecule on the surface of
the flu virus that attaches the cells it infects
 Neuraminidase: molecule on the surface of
the virus that allows newly-made viruses to
escape the infected cell
 There are 16 H subtypes and 9 N subtypes
◦ H17 discovered in Guatemalan bats
 Human influenza is usually caused by H1, H2,
or H3 and N1 or N2 subtypes

12.  Influenza infects birds and mammals
◦ Economic loss
◦ Food insecurity
 All 16 hemagglutinin and all 9 neuraminidase
subtypes found in birds
 Birds and humans have different sialic acid
receptors
◦ humans are not usually infected with avian
influenzas
 Pigs have both types of receptors

13. NIH, 2009

14. CDC/ Douglas Jordan, 2009

17. Garten et al., 2009

18. Smith et al., 2009

20.  Emergence of a novel virus
 Little or no immunity in the population
 Higher attack rates
 Worldwide spread
 Affects younger adults
◦ W-shaped mortality curve
Taubenberger & Morens, 2006; Treanor, 2015

21.  1918 H1N1 “Spanish flu”
◦ 50 to 100 million deaths worldwide
 1957 H2N2 “Asian flu”
◦ 1.1 million deaths
 1968 H3N2 “Hong Kong flu”
◦ 1 million deaths
 1977 reemergence of H1N1
 2009 H1N1
◦ 151,700 to 575,400 deaths worldwide
CDC, 2016; Treanor, 2015

22.  March 17, 2009
◦ Mexico: first case
 March 28 & 30
◦ First two cases in California
 April 27:
◦ U.S.:
 40 laboratory-confirmed cases
◦ Mexico
 26 confirmed cases
◦ Canada
 6 confirmed cases
CDC, WHO, 2009

23.  April 29, 2009
◦ US:
 91 confirmed cases
 Half of the U.S. cases were reported from New
York City high schools
 1 death
◦ Austria, Germany, Israel, New Zealand, Spain, and
United Kingdom reporting cases
CDC, WHO, 2009

24. WHO, 2009

25.  Worldwide: 80% of deaths were people under
65 years of age
 U.S.: 76% of deaths were people between the
ages of 18 and 65 years
◦ 9% were people ≥ 65 years of age
◦ Pierce County 2016-17: 81% of flu deaths are ≥ 65
years of age
 Pregnant women were 4 times more likely to
be hospitalized than the general population
Dawood et al., 2012; Fowlkes et al., 2011;
Jamieson et al., 2009

26. Median age: 48
years
YPLL<75: 340
Median age: 79 years
YPLL<75: 251

27.  Interim estimate of 2016-17 influenza vaccine
effectiveness: 48%
◦ Risk reduction
CDC, 2017

28. STAT, February 28, 2017

29. CDC, 2017

30. USDA, 2014

31.  Centers for Disease Control and Prevention. (2016). Past pandemics.
Retreived February 27, 2017 from https://www.cdc.gov/flu/pandemic-
resources/basics/past-pandemics.html.
 Centers for Disease Control and Prevention. (2017). Interim estimates of
2016-17 seasonal influenza vaccine effectiveness - United States,
February 2017. Morbidity and Mortality Weekly Report, 66(6), 167-171.
 Dawood, F. S., Iuliano, A. D., Reed, C., Maltzer, M. I., Shay, D. K., Cheng,
P-Y., et al. (2012). Estimated global mortality associated with the first 12
months of 2009 pandemic influenza A H1N1 virus circulation: a
modeling study. Lancet Infectious Diseases, 12(9), 687-695.
 Fowlkes, A. L., Arguin, P., Biggerstaff, M. S., Gindler, J., Blau, D., Jain, S.,
et al. (2011). Epidemiology of 2009 pandemic influenza A (H1N1) deaths
in the United States, April-July 2009. Clinical Infectious Diseases,
52(Supple. 1), S60-S68.
 Garten, R. J., Davis, C. T., Russell, C. A., Shu, B., Lindstrom, S., Balish, A.,
et al. (2009). Antigenic and genetic characteristics of swine-origin 2009
A(H1N1) influenza viruses circulating in humans. Science, 325(5937),
doi:10.1126/science.1176225.

32.  Jamieson, D. J., Honein, M. A., Rasmussen, S. A., Williams, J. L., Swerdlow, D.
L., Biggerstaff, M. S., et al. (2009). H1N1 2009 influenza virus infection
during pregnancy in the USA. Lancet, 374(9688), 451-458.
 Smith, G. J. D., Vijaykrishna, D., Bahl, J., Lycett, S. J., Worobey, M., Pyrus, O.
G., et al., (2009). Origins and evolutionalry genomics of the 2009 swine-
origin H1N1 influenza A epidemic. Nature, 459(7250),
doi:10.1038/nature08182.
 Taubenberger, J. K. & Morens, D. M. (2006). 1918 influenza: the mother of all
pandemics. Emerging infectious diseases, 12(1),
doi:10.3201/eid1201.050979.
 Treanor, J. J. (2015). Influenza (including avian influenza and swine
influenza). In G. L. Mandell, J. E. Bennett, & M. J. Blaser (Eds.). Mandell,
Douglas, and Bennett's principles and practice of infectious diseases (8th Ed.)
[Electronic version].