Embed Size (px)
DESCRIPTION
Allison McGeer, MSc, MD, FRCPC
Citation preview
2009 Influenza A(H1N1) – Human Swine FluIs this the pandemic?
2009 Influenza A(H1N1) – Human Swine FluIs this the pandemic?
Allison McGeer, MSc, MD, FRCPC
Mount Sinai Hospital
University of Toronto
Allison McGeer, MSc, MD, FRCPC
Mount Sinai Hospital
University of Toronto
Nasal Congestion
Sore Throat
Muscle Pains
Headache
Cough
Malaise
Infectious
Clinical Characteristics of Seasonal Influenza InfectionClinical Characteristics of Seasonal Influenza InfectionClinical Characteristics of Seasonal Influenza InfectionClinical Characteristics of Seasonal Influenza Infection
Days After Onset 0 1 2 3 4 5 6 7 8
Nöel GE. Life-threatening “flu”? Nöel GE. Life-threatening “flu”? Can J DiagnosisCan J Diagnosis 1999;Mar 1999;Mar
Fever
Be an influenza virus, see the world
Changes in Influenza VirusesChanges in Influenza VirusesChanges in Influenza VirusesChanges in Influenza Viruses
Antigenic drift (continuous mutation) – minor changes in A & B strains, same subtype– every year while virus is in humans
Antigenic shift (recombination with non-human viruses)– produce new subtype with changed H and/or N– population has no immunity to this new virus
Antigenic drift (continuous mutation) – minor changes in A & B strains, same subtype– every year while virus is in humans
Antigenic shift (recombination with non-human viruses)– produce new subtype with changed H and/or N– population has no immunity to this new virus
HumanHuman virusvirus
ReassortantReassortantvirusvirus
AvianAvianvirusvirus
16 HAs16 HAs 9 NAs9 NAs
Mechanisms of Antigenic Shift
SwineSwinevirusvirus
2009 H1N1 influenza A2009 H1N1 influenza A2009 H1N1 influenza A2009 H1N1 influenza A April 10-15
– Mexican authorities recognize increase in acute respiratory disease/pneumonia, especially in young adults
April 17– US recognizes new influenza strain, mostly
derived from pigs (a “swine” flu), in two unrelated children in California
April 10-15– Mexican authorities recognize increase in acute
respiratory disease/pneumonia, especially in young adults
April 17– US recognizes new influenza strain, mostly
derived from pigs (a “swine” flu), in two unrelated children in California
2009 A(H1N1) – Human Swine flu2009 A(H1N1) – Human Swine fluDiseaseDisease2009 A(H1N1) – Human Swine flu2009 A(H1N1) – Human Swine fluDiseaseDisease
Symptoms – typical influenza Fever (>90%)
Cough (>90%) “Prostration”
Nasal congestion Sore throat (66%)
Diarrhea (25%) Vomiting (25%)
Symptoms – typical influenza Fever (>90%)
Cough (>90%) “Prostration”
Nasal congestion Sore throat (66%)
Diarrhea (25%) Vomiting (25%)
Provisos
Almost certainly, milder disease occurs
More severe disease likely won’t present “typically”
Provisos
Almost certainly, milder disease occurs
More severe disease likely won’t present “typically”
How severe is it?– WHO totals: 61 deaths / 5728 cases
Case fatality rate=1%
How severe is it?– WHO totals: 61 deaths / 5728 cases
Case fatality rate=1%
2009 A(H1N1) – Human Swine flu2009 A(H1N1) – Human Swine fluDiseaseDisease2009 A(H1N1) – Human Swine flu2009 A(H1N1) – Human Swine fluDiseaseDisease
How severe is it?– WHO totals: 61 deaths / 5728 cases
Case fatality rate=1%
– WHO Rapid Pandemic Assessment Collaboration (Science 11 May)
Case fatality rate: 0.4% (0.3-1.5%)
0 (U95%CL 0.6%)
How severe is it?– WHO totals: 61 deaths / 5728 cases
Case fatality rate=1%
– WHO Rapid Pandemic Assessment Collaboration (Science 11 May)
Case fatality rate: 0.4% (0.3-1.5%)
0 (U95%CL 0.6%)
2009 A(H1N1) – Human Swine flu2009 A(H1N1) – Human Swine fluDiseaseDisease2009 A(H1N1) – Human Swine flu2009 A(H1N1) – Human Swine fluDiseaseDisease
No – not quite “humanized”
Yes – and “first wave” will start in the next few weeks
Yes – but “first wave” won’t start until sometime in the fall
No – not quite “humanized”
Yes – and “first wave” will start in the next few weeks
Yes – but “first wave” won’t start until sometime in the fall
2009 A(H1N1) – Human Swine flu2009 A(H1N1) – Human Swine fluIs it the next pandemic?Is it the next pandemic?2009 A(H1N1) – Human Swine flu2009 A(H1N1) – Human Swine fluIs it the next pandemic?Is it the next pandemic?
So, what are we doing in hospitals?So, what are we doing in hospitals?So, what are we doing in hospitals?So, what are we doing in hospitals?
Brushing off our pandemic plans, and activating phase 5
Filling in the gaps Recognizing that the pressure in ICUs may
be less than anticipated, but the workload in ED and primary may be higher
Brushing off our pandemic plans, and activating phase 5
Filling in the gaps Recognizing that the pressure in ICUs may
be less than anticipated, but the workload in ED and primary may be higher
