Influenza in Alberta

2013-2104 Season

Kim Simmonds, Manager Infectious Disease Epidemiology

Alberta Health

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2012-2013 Year in Review• The 2012/2013 influenza season in North

America began earlier, peaked earlier, and was longer than other seasons since 2003, with the exception of the 2009 season.

• The predominant strain was H3N2, with a late wave of Influenza B

• Highest rate of cases elderly (80+), infants <1, and children 1 to 4.

• Influenza Cases:– 28,933 Albertans were diagnosed with ILI– 2,871 laboratory confirmed – 964 hospitalized– 150 ICU – 37 deaths

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H1N1 2013-2014 SeasonA timelineDecember 20:

o Alberta Health is notified of the cases of severe influenza on ECMO (extracorporeal membrane oxygenation).

o Cases of H1N1 are rapidly increasingDecember 23:

o Mini-EOC opened at Alberta HealthDecember 24:

o Media reports the increase in number of H1N1 casesDecember 27:

o Mass immunizations clinics opened January 10:

o Mini-EOC closed at Alberta HealthJanuary 11:

o Alberta Health Services announces vaccine is no longer available

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A Twitter over vaccine & flu

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Canada December 29 to January 4, 2014 (Week 1)

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No Activity

Sporadic Activity

Localized Activity

Widespread Activity

Immunizations

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Immunizations

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2011-12 2012-13 2013-140

100,000

200,000

300,000

400,000

500,000

600,000Influenza Immunizations by Provider, by Season

AHS Pharmacy Physicians

Indi

vidu

als I

mm

unize

d

Influenza Activity

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TARRANT Reporting

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Influenza Cases-Lab Confirmed

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Influenza by Zone • Rates are highest in

North and Central Zones.

• Rates of hospitalization are highest in the North, Edmonton & Central Zones

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Hospitalized Cases

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Hospitalized Cases by Zone

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Zone H5N1 Influenza A H1N1

Influenza A H3

Influenza A

Untyped

Influenza B Total

South Zone 0 49 0 2 0 51Calgary Zone 0 276 6 20 11 313Central Zone 1 103 1 19 4 128Edmonton Zone 0 282 10 52 10 354

Northern Zone 0 118 0 12 0 130

Total 1 828 17 105 25 976

Zone by Influenza Strain

Hospital, ICU & Deathsfor H1N1 & untyped Cases

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Hospitalizations ICU Deaths(n=933) (n=158) (n=33)

Age (median, range) 53 (0-93) 51 (0-83) 55 (17-91)

Gender (males, females) 468 M, 465 F 83 M,75 F 14 M, 19 F

No co-morbidities 29%(266/933) 13%(20/158) 15% (5/33)One comorbidity 30%(285/933) 34% (54/158) 18% (6/33)

Two or more comorbidities 41% (382/933) 53% (84/158) 67% (22/33)

Immunized-current year 15% (140/933) 12% (19/158) 9% (3/33)Immunized-previous

year 20% (183/933) 14% (22/158) 15% (5/33)

Outbreaks

• There were fewer institutional outbreaks this year compared to last year.– 31 outbreaks in 2013/14 – 83 outbreaks in 2012/13

• More school and daycare outbreaks were seen this year compared to previous years.

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2013-2014 Summary (so far)• The 2013/2043 influenza season had a sudden

rise and fall in the rate of disease.• The predominant strain was H1N1• Highest rate of cases infants <1, and children 1

to 4.• Adults had a higher rate of disease than

previous years• Influenza Cases:

– 23,173 Albertans were diagnosed with ILI– 3,208 laboratory confirmed – 933 hospitalized– 158 ICU – 33 deaths

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Questions?Kimberley.simmonds@gov.ab.ca

780.422.1940

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Thank you to Larry Svenson & Allison Scott