1 / 13

Preparing for the Next Influenza Pandemic Oct 19, 2005

Learn about the history of influenza viruses, the potential risks of a future pandemic, and the steps being taken to prepare for it. Discover the importance of vaccination and education in preventing the spread of the virus.

rameriz
Download Presentation

Preparing for the Next Influenza Pandemic Oct 19, 2005

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Preparing for theNext Influenza PandemicOct 19, 2005 W. David Colby, MSc, MD, FRCPC Acting Medical Officer of Health Chatham-Kent

  2. Influenza • A small and simple virus • Like all viruses, not a living thing • A hollow lipid ball studded with two surface proteins containing 8 RNA gene segments • Induces living host cells to manufacture more virus particles

  3. Human Flu • Fever, chills, cough and myalgia • Lasts 3-5 days • Usually a minor illness in the young and healthy • Often fatal in the elderly and those with cardiorespiratory disease • The flu is not vomiting and diarrhoea!

  4. Influenza viruses • Three kinds: A, B and C • B and C infect only humans and have never caused pandemics • Influenza A is naturally found in the gut of aquatic birds like ducks • A can infect poultry, swine, horses and humans

  5. Influenza Surface Proteins • Hemagglutinin:  15 subtypes (1, 2, 3…) • Neuraminidase: 9 subtypes (1,2,3…)

  6. New Influenza Strains:Usually Arise in China • Antigenic Drift: Point mutations in the genes that code for the surface proteins HA and NA. Minor antigenic variations from year to year within same HA/NA types. • Antigenic Shift: When two different viruses infect one host cell, their genes can mix and produce a different HA/NA type. Major antigenic variation:  Pandemic!

  7. Pandemic Human Influenza Strains of the 20th Century • 1918 H1N1, the Spanish Influenza -killed 40 million in 1918-1919 season, more than WW1 -50 X more lethal than most strains 2.5-5% mortality -especially deadly in young & healthy • 1957 H2N2, the Hong Kong Flu • 1968 H3N2, the Asian Flu

  8. Avian Influenza A • Can infect all species of birds • Until recently, it was thought that avian strains could not infect humans… • 1997: 18 people were infected with an avian H1N5 in Hong Kong, six died • 2003-2004: H1N5 widespread in Asian poultry, >30 human deaths in Vietnam and Thailand • Risk factor: close contact with poultry

  9. Avian Influenza A • Wave of H1N5: 16 cases June-Sept 2004, 13 died (4 in 2005, all young) • Has spread to China, Indonesia, Cambodia, Malaysia and Viet Nam • H7N7, H7N3 and H9N2 have also caused human infections • April 2004: H7N3 outbreak in Fraser Valley BC, 19 million birds destroyed, two human cases (+ 55 suspect)

  10. Portents of Trouble • The 1918 Spanish Influenza (H1N1) gene sequence has been recovered from old pathology specimens and from corpses in permafrost from Brevig Mission, Alaska • The 1918 H1 hemagglutinin produces an intense immune response • The avian H5 is structurally very close structurally to the 1918 H1 • Ongoing technical/logistical problems

  11. Recent Developments • Canadian Pandemic Influenza Plan released February 2004 • Human to human transmission of avian influenza documented September 2004 • As of Oct 14, > 100 human cases, 50% mortality • WHO calls emergency meeting November 11, 2004 to consolidate plans for pandemic preparedness: • Now Phase 3 • Domestic ducks excrete, expanded host range

  12. What Would Probably Happen in Chatham-Kent? • 27,000 people would get sick over a 6-12 week period, 3,000 per week • Each Week, for influenza alone: -1500 would need medical assessment and treatment -32 would need hospital admission -12 would die • These are conservative estimates

  13. The Chatham-Kent Public Health Unit • We are planning • Prevention: influenza vaccination education, infrastructure • Reactive: drug prophylaxis, coordinate with health care sectors and C-K Municipality (stress on hospitals, physicians, coroners will be immense) • Leadership

More Related