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Bureau of Emergency Preparedness and Response. Pandemic Influenza: history and background. Peter C. Kelly, M.D., FACPArizona Dept. of Health Services. Bureau of Emergency Preparedness and Response. Drivers for Pan Flu Preparedness. WHO Influenza PreparednessSARS and TorontoHurricane Katrina and
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1. Bureau of Emergency Preparedness and Response 88 Years of Influenza Pandemics in 15 Minutes Peter C. Kelly, M.D.
Arizona Dept. of Health Services
2. Bureau of Emergency Preparedness and Response Pandemic Influenza: history and background Peter C. Kelly, M.D., FACP
Arizona Dept. of Health Services
3. Bureau of Emergency Preparedness and Response Drivers for Pan Flu Preparedness WHO Influenza Preparedness
SARS and Toronto
Hurricane Katrina and New Orleans
4. Bureau of Emergency Preparedness and Response Its all about the virus
5. Bureau of Emergency Preparedness and Response Influenza Virus RNA, 8 segments
Unstable,mutates frequently
Surface proteins
Hemagglutinin
Neuraminidase
Niche in nature is birds
6. Bureau of Emergency Preparedness and Response Drift and Shift Both refer to genetic changes
Drift: Minor changes in H and N antigens; occur annually or every few years
Shift: Major change (30% or more) in H and/or N antigens; new virus. Important for starting pandemics
7. Bureau of Emergency Preparedness and Response Influenza is Global
8. Bureau of Emergency Preparedness and Response Surface Glycoproteins Used to classify virus; H1, H2 etc
Important in disease
HA attaches virus to respiratory epithelial cells
NA facilitates release of virus from infected cell
Immunity/vaccines
9. Bureau of Emergency Preparedness and Response Influenza Virus and Birds Migratory waterfowl
Often not diseased
Transmit to domestic birds and other animals
15 H types, 9 N types
Only 3 H,2 N in humans
Pathogenicity varies
10. Bureau of Emergency Preparedness and Response How does the virus get to humans?
11. Bureau of Emergency Preparedness and Response How does the virus get from person to person?
12. Bureau of Emergency Preparedness and Response How does the virus cause disease? Attaches to respiratory epithelium
Enters the cell and reproduces
Causes cell death
Primary target is bronchial tissue
13. Bureau of Emergency Preparedness and Response Pandemics
14. Bureau of Emergency Preparedness and Response Required for Influenza Pandemic New virus (antigenic shift)
Susceptible population
Transmitted from animals to humans
Cause disease in humans
Efficient person to person transmission
15. Bureau of Emergency Preparedness and Response Influenza Pandemics Have occurred for centuries
Occur 11 to 42 years apart
Unpredictable but not random
Attack rates of 10 to 40%
Excess mortality
But humanity survives
16. Bureau of Emergency Preparedness and Response 20th Century
17. Bureau of Emergency Preparedness and Response Current Model of Pandemics
18. Bureau of Emergency Preparedness and Response 1918-19 Pandemic aka Spanish Flu
H1N1 virus,
Genetics: avian like
First cases in USA
Global spread ~1 yr
Mortality 20-50 million
USA 500,000
19. Bureau of Emergency Preparedness and Response Impact High mortality
Social disruption
Burial
Public services
Events cancelled
Spread along troop transport routes
Poor public health response
20. Bureau of Emergency Preparedness and Response Mortality and WavesTaubenberger, Morens. EID. 2006;12: 15-22.
21. Bureau of Emergency Preparedness and Response the Mother of All PandemicsTaubenberger, Morens.EID.2006;12:15-22 H1N1 1918 virus is the ancestor of current influenza viruses
Human and porcine lineage have some H1N1 genes
H3N2 virus retains some H1N1 genes
None of these as virulent as original
22. Bureau of Emergency Preparedness and Response 20th Century
23. Bureau of Emergency Preparedness and Response 1957-58 Influenza PandemicAsian Influenza H2N2 virus: 3 new genes (H,N, PB1); 5 genes from 1918 H1N1
First cases in China
Spread around world in 6 months
1st wave: Fall57 school age
2nd wave: Jan58 adults
80,000 deaths in USA
Very young and elderly
24. Bureau of Emergency Preparedness and Response 20th Century
25. Bureau of Emergency Preparedness and Response 1968-69 Influenza PandemicHong Kong Influenza H3N2 Virus, 2 new genes(H, PB1), 5 retained from 1918. N2 from Asian
Only 1 antigen shifted
Population has some immunity to N2
26. Bureau of Emergency Preparedness and Response H3N2 Influenza Lowest mortality of 20th cent. pandemics
34,000 deaths in USA
U shaped mortality curve
27. Bureau of Emergency Preparedness and Response Wave Phenomenon
28. Bureau of Emergency Preparedness and Response Where are we now? H3N2 era. Seasonal influenza. Antigenic drift. Annual vaccine. Mortality ~36,000
SURPRISE
2003 H5 N1 avian virus
Highly pathogenic in birds, especially chickens
Almost world wide spread (asia,africa,and europe)
29. Bureau of Emergency Preparedness and Response
30. Bureau of Emergency Preparedness and Response
31. Bureau of Emergency Preparedness and Response
32. Bureau of Emergency Preparedness and Response Humans and H5N1 HPAI Few cases in close contact with chickens
As of 7/14/06; 230 cases and 132 deaths
No efficient human to human transmission
33. Bureau of Emergency Preparedness and Response Required for Influenza Pandemic New virus (antigenic shift)
Susceptible population
Transmitted from animals to humans
Cause disease in humans
Efficient person to person transmission
34. Bureau of Emergency Preparedness and Response WHO Alert
35. Bureau of Emergency Preparedness and Response International Preparedness Control in birds
Global Influenza Surveillance
Vaccine development
Antiviral drugs, oseltamivir
National preparedness plans
36. Bureau of Emergency Preparedness and Response Be an optimist! Power of scientific inquiry
WHO global surveillance is good and getting better
Communication and cooperation among nations is better since SARS
Vaccine development and production methods are on a fast track
37. Bureau of Emergency Preparedness and Response What about state and local PH?