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88 Years of Influenza Pandemics in 15 Minutes

88 Years of Influenza Pandemics in 15 Minutes. Peter C. Kelly, M.D. Arizona Dept. of Health Services. It’s all about the virus. Influenza Virus. RNA, 8 segments Unstable,mutates frequently Surface proteins Hemagglutinin Neuraminidase Niche in nature is birds. Drift and Shift.

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88 Years of Influenza Pandemics in 15 Minutes

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  1. 88 Years of Influenza Pandemics in 15 Minutes Peter C. Kelly, M.D. Arizona Dept. of Health Services Bureau of Emergency Preparedness and Response

  2. It’s all about the virus Bureau of Emergency Preparedness and Response

  3. Influenza Virus • RNA, 8 segments • Unstable,mutates frequently • Surface proteins • Hemagglutinin • Neuraminidase • Niche in nature is birds Bureau of Emergency Preparedness and Response

  4. 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 Bureau of Emergency Preparedness and Response

  5. Influenza is Global Bureau of Emergency Preparedness and Response

  6. Pandemics Bureau of Emergency Preparedness and Response

  7. Required for Influenza Pandemic • “New” virus (antigenic shift) • Susceptible population • Transmitted from animals to humans • Cause disease in humans • Efficient person to person transmission Bureau of Emergency Preparedness and Response

  8. 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 Bureau of Emergency Preparedness and Response

  9. 20th Century Bureau of Emergency Preparedness and Response

  10. 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 Bureau of Emergency Preparedness and Response

  11. Impact • High mortality • Social disruption • Burial • Public services • Events cancelled • Spread along troop transport routes • Poor public health response Bureau of Emergency Preparedness and Response

  12. Mortality and “Waves”Taubenberger, Morens. EID. 2006;12: 15-22. Bureau of Emergency Preparedness and Response

  13. “the Mother of All Pandemics”Taubenberger, 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 Bureau of Emergency Preparedness and Response

  14. 20th Century Bureau of Emergency Preparedness and Response

  15. 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: Fall’57 school age • 2nd wave: Jan’58 adults • 80,000 deaths in USA • Very young and elderly Bureau of Emergency Preparedness and Response

  16. 20th Century Bureau of Emergency Preparedness and Response

  17. 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 Bureau of Emergency Preparedness and Response

  18. H3N2 Influenza • Lowest mortality of 20th cent. pandemics • 34,000 deaths in USA • U shaped mortality curve Bureau of Emergency Preparedness and Response

  19. Wave Phenomenon Bureau of Emergency Preparedness and Response

  20. 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) Bureau of Emergency Preparedness and Response

  21. 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 Bureau of Emergency Preparedness and Response

  22. Required for Influenza Pandemic • “New” virus (antigenic shift) • Susceptible population • Transmitted from animals to humans • Cause disease in humans • Efficient person to person transmission Bureau of Emergency Preparedness and Response

  23. 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 Bureau of Emergency Preparedness and Response

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