Francisco George

DIRECTORATE-GENERAL OF HEALTH

Influenza A(H1N1)2009

Notes on Influenza

• The most frequent zoonosis

• Reservoir

• Multiple hosts

• Species barrier

• Epizootics and epidemics

• Impossible to erradicate

• Individually avoidable

About the 2009 Pandemic

• Expected phenomenon• Fast global ignition process

Phase 4 Phase 5 Phase 6 Portugal

• No pandemics are alike:

1889, 1900, 1918, 1957, 1968, 2009

• Different issue from seasonal influenza• Emergence of the A(H1N1)2009 virus

H1 generations

Global situation

• Worldwide impact– Ongoing spread of infection over both

hemispheres– Common trends in each hemisphere

• National impact– Variable patterns according to location– Flu activity with up & down pattern over the

weeks

Source: WHO

Global situation• Southern hemisphere

– General widespread infection, though decreasing as Winter ends

• Northern hemisphere– General flu activity during all Summer– Japan reporting a significant increase of ILI

cases

Source: WHO

Global situation• Some aspects differ from seasonal

flu:– High activity during Summer, in the northern

hemisphere– Severe and fatal cases mainly in younger age

groups– Death mainly associated with a rapid

respiratory failure

• Very fast worldwide spreading– All world regions in just 9 weeks

Source: WHO

Global situationLab. confirmed cases in Chile, EU and EFTA countries, Japan, Panama

and Mexico

Source: WHO

Global situation

• Wide spectrum of severity (no symptoms death)– Proportion of cases with no symptoms not yet

established• Majority of patients develops self-limited clinical

cases• Risk groups:

– Pregnancy, chronic respiratory disease, cardiovascular diseases, diabetes, obesity, immunodepression.

Source: WHO

• Most patients recover without hospitalization• Care-providers must pay attention to signs of

aggravation:– Risk groups– Severe respiratory failure can develop very

quickly• Guidelines issued on care provision and use of

antivirals

Global situation

Source: WHO

Global situation

• Viruses remain unchanged– Will evolve and diverge over time– Sensitive to oseltamivir and zanamivir– Resistant to amantadine and rimantadine– 12 cases of oseltamivir resistance reported

• Increased incidence of the pandemic virus

Source: WHO

Situation in Portugal

• Containment phase - April 24 – August 21– First reported case - April 29– First secondary case - July 4– First cluster - July 5– 100 cumulative cases - July 14– 1000 cumulative cases – August 14– 2000 cumulative cases – August 21

• Mitigation phase - August 21

Coordination

• Minister of Health

• DGS, INSA,INFARMED, INEM

• Emergency Coordination Committee

• Articulation with all sectors involved

• Involvement of citizens, families and enterprises

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Casos importados Casos sec. ou terc. com link Casos sec. sem link Total de casos

Cumulative cases

Containment

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Importado

Progression

15%

28%

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6% 5%2%

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CASE

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AGE GROUPS

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Age groups

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Taxa

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%)

Grupos etários

MF

M

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Attack rate

83%

16%1%

CONTINENT

AZORES

MADEIRA

Cases by region

(N=3467)

82%

11%1%6%

LIGHT

MODERATE

SEVERE

UNKNOWN

Clinical severity

(N=1816)

32%

63%

5%

YES

NO

UNKNOWN

Use of antivirals(oseltamivir)

(N=1106)

Week 39

• Cumulative cases: 3472 (lab confirmed)

• Weekly incidence of lab confirmed cases: 259

• ILI weekly incidence (estimated): 1271

• Hospitalized cases: 21– ICU: 6

Without intervention

With intervention

Num

ber

of d

aily

cas

es

No of weeks from first reported case

Based on data from CDC Atlanta.

Containment

Thank you

franciscogeorge@dgs.pt