2000 and Beyond: Confronting the Microbe Menace

Lecture 4 – Emerging Infections: How Epidemics Arise

by Donald E. Ganem, MD
  1.  1.  Start of Lecture 4
  2.  2.  Introduction by HHMI Vice President Dr. Joseph Perpich
  3.  3.  Interview with Dr. Donald Ganem: What I like about being a scientist
  4.  4.  How do new epidemics arise?
  5.  5.  New diseases arise from disruption of virus-host equilibrium
  6.  6.  Genetic changes in viruses: Mutation and recombination
  7.  7.  High rate of mutation in RNA viruses
  8.  8.  Mutations that do not change the amino acid sequence
  9.  9.  Why do RNA-based genomes have a higher mutation rate?
  10. 10.  DNA proofreading mechanism
  11. 11.  Consequences of an elevated mutation rate
  12. 12.  Influenza virus: Protein and genomic structure
  13. 13.  Pathology of influenza
  14. 14.  Influenza epidemics caused by antigenic drift
  15. 15.  Influenza pandemics caused by antigenic shift
  16. 16.  Genetic basis of antigenic drift
  17. 17.  Molecular structure of hemagglutinin
  18. 18.  Genetic basis of antigenic shift
  19. 19.  Origin of different influenza hemagglutinin types
  20. 20.  Animation: Recombination of viral RNA in a host cell
  21. 21.  Where does recombination take place in nature?
  22. 22.  Environmental changes can cause new epidemics: Hantavirus
  23. 23.  What environmental change was responsible for the hantavirus epidemic?
  24. 24.  Human migration affects epidemic patterns: Smallpox
  25. 25.  Why was smallpox so much more severe among Native Americans?
  26. 26.  Lesson learned from rabbits in Australia
  27. 27.  Myxoma virus as a rabbit-control agent
  28. 28.  Less virulent myxoma strains emerge and maximize the spread of disease
  29. 29.  Natural selection results in minimized susceptibility to disease
  30. 30.  Comparing the myxoma virus in Australian rabbits and smallpox in Native Americans
  31. 31.  What forces will shape the epidemics of the future?
  32. 32.  Subtle changes affecting spread of diseases: Dengue fever and West Nile virus
  33. 33.  Conclusion
  34. 34.  Student question: Can we create a vaccine that covers all influenza strains?
  35. 35.  Student question: How do DNA viruses mutate?
  36. 36.  Student question: Can different species of bacteria and viruses trade genes?
  37. 37.  Student question: How do researchers and health organizations share information?
  38. 38.  Student question: Are some regions of the influenza genome more mutable?
  39. 39.  Closing remarks by HHMI Vice President Dr. Joseph Perpich
  40. 40.  Closing remarks by HHMI President Dr. Purnell Choppin


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