Impending Doom !

1. Impending Doom ! The World Coming To An End Part III

2. Disease Occurrence • Endemic – normal levels within geographic regions. • Epidemic – sudden severe outbreak within a region. • Pandemic – epidemic becomes widespread (worldwide).

3. Pandemic • Global outbreak. • Caused by new subtypes – novel pathogen. • High person-to-person susceptibility. • Unusually high mortality. Cholera Pandemic Cartoon, 1883

4. versus Epidemic Pandemic • Seasonal (mainly winter) • Known pathogen • Elderly affected most • Vaccine available • Localized occurrence • Any time of year • Unknown pathogen • Atypical age groups • No proven/available vaccine • Worldwide occurrence Most epidemics and pandemics caused by influenza.

5. Influenza Three Types • Type A • Regular outbreaks • Most widespread • Responsible for pandemics • Infects humans and animals

6. Influenza Three Types • Type B • Sporadic outbreaks • Mainly occurs in residential communities (e.g. nursing homes) • Infects humans only • Can cause epidemics, have not caused pandemics

7. Influenza Three Types • Type C • Common • Causes very mild symptoms or none at all • Not a severe public health threat

8. Influenza A Virus • ssRNA virus • Contains two membrane proteins • Hemagglutinin (“H”) • - Initiates infection by binding to receptors on host cell’s membrane. • Neuraminidase (“N”) • - Enzymatic properties of N destroy host cell receptors and allows viral infection of cell.

9. Influenza A Virus • Subtypes vary by types of H and N membrane proteins • - 15 different H proteins identified (H1, H2, etc.) • - 9 different N proteins identified (N1, N2, etc.) • Virus identified and named by H and N membrane proteins • Many different combinations of H and N proteins possible • Only some Influenza A subtypes currently cause human infection • - H1N1, H2N2, and H3N2 • Others are common in animal species • All common in avian species

10. Pandemics of 20th Century • Spanish Flu – 1918 – A (H1N1) • 50 million dead worldwide • 500,000 dead in U.S. • Asian Flu – 1957 – A (H2N2) • 70,000 dead in U.S. • Hong Kong Flu – 1968 – A (H3N2) • 34,000 dead in U.S.

11. The Case of Harry Tyson 54 year old male brought to Norfolk General Hospital

12. Patient presented with: • Fever (103.2 degrees F) • Productive cough with blood • Sore throat • Myalgia (General muscle pain) • Dyspnea (Difficulty breathing) on day 5

13. Subsequent Complications: • Respiratory failure on day 5 and ARDS • Renal and Cardiac failure days 6 & 7 • Died on day 8 • Wife and son admitted on day 5 • with similar symptoms

14. Initial Treatment & Diagnosis • Patient given Oseltamivir on days 5-8 with no improvement • Wife and son also administered drug • Son died on day 14 and mother recovered • Initial diagnosis: Influenza with complicating secondary bacterial pneumonia

15. Final Diagnosis • Father owned chicken farm where family worked • Father involved in breeding hybrid chicken • Large Asian variety with fast producing American variety • Father imported eggs from S.E. Asia illegally • Exposed to products of the eggs

16. Suspected Pathogen: Influenza Virus A (H5N1) • Father, Mother, and son all test positive • Chickens test positive • The USDA and CDC contacted • Farm Quarantined • Chickens Destroyed

17. So, you have the flu… Virus causes upper and or lower respiratory tract infection as the virus uses cells for lytic reproduction

18. Symptoms of the Flu • Fever • Cough and runny nose • Malaise with myalgia • Headache, sore throat • Extreme tiredness

19. What is the respiratory tract?

20. Respiratory Tract Function • Gas exchange - Take in oxygen and expel carbon dioxide • Sound - Movement of gas through mouth and over larynx and pharynx allows sound production

21. Respiratory Tract Microbes • Normal Flora - Regular inhabitants - Rarely cause disease Gram negative cocci and gram positive rods from Ms. Shepard’s throat. Staphylococci sp. Cultured from Mr. Styer’s throat.

22. Respiratory Tract Microbes • Nose • Staphylococcus spp. • Staphylococcus aureus • Staphylococcus epidermidis • Mouth and Oropharynx • Staphylococcus epidermidis • Streptococcus pneumoniae • Other Streptococcus spp. • Neisseria spp. • Haemophilus spp. • Anaerobic bacteria • Yeasts Staphylococcus aureus

23. Respiratory Tract Infections • Respiratory tract constantly exposed to outside environment. • Exposure to many airborne microbes.

24. Respiratory Tract Defense • Physical barriers URT • Mucus • Cilia • Physical barriers LRT • Phygocytosis – killer white blood cells

25. Respiratory Tract Pathogens • Upper Respiratory Tract • Viruses • Corona viridae • Adeno viridae • Rhino viridae • Group A Streptococcus • Corynebacterium diptheriae • Bordetella pertussis

26. Respiratory Tract Pathogens • Lower Respiratory Tract • Viruses • Influenza • SARS • Haantavirus • Bacterial Pneumonia • Streptococcus pneumoniae • Mycoplasma pneumoniae • Pseudomonas aeruginosa • Legionella pneumophila

27. The Monster That Looms: H5N1 • Currently unable to transmit human-to-human (as seen with H1, H2 & H3 strains) • Infection only with direct contact with infected animal • Can infect across breeds: birds and mammals • Causes atypical immune response • “Cytokine Storm” that body cannot handle • Fluid (blood) fills the lungs as body fails • Secondary infections are rampant • Seen in the “Spanish Flu” of 1918

28. Review and Reflection • Differentiate Epidemic and Pandemic outbreaks: • Give the parts and function of each part of the respiratory tract: • Give our typical respiratory tract defense against infection: • List two non-pathogenic and two pathogenic respiratory tract microbes: • Describe how an H2N2 strain of virus differs from an H5N2 strain. For which one is there a vaccine available? • Describe what is meant by a secondary bacterial infection and how would a hospital test for this?

29. Writing Prompt • Write a one page, double-spaced essay on what you think would happen if there was, in fact, an influenza AH5N1 outbreak. How would we react to the threat both locally and globally ? What would we have to do to contain the disease, yet survive as a society? Examine the effect on things like the economy, travel, as well as on everyday life such as school and grocery shopping. Be thoughtful and creative!

30. Citations Centers for Disease Control and Prevention (2005). Information About Influenza Pandemics [Internet]. Fact Sheet [cited July 28, 2005] http://www.cdc.gov/flu/avian/gen-info/pandemics.htm Centers for Disease Control and Prevention (2005). Key Facts About Influenza and Influenza Vaccine [Internet]. Fact Sheet [cited July 28, 2005] http://www.cdc.gov/flu/keyfacts.htm Centers for Disease Control and Prevention (2004). Update on Avian Influenza A (H5N1) [Internet]. Health Alert Network. [cited July 28, 2005] www.phppo.cdc.gov/han/archivesys/viewmsgv.asp?alertnum=00209 Images Used Cholera Pandemic Picture http://www.authentichistory.com/images/postcivilwar/cartoons/1883_cholera_pandemic_cartoon.html Portrait of Harry Tyson http://ring.uvic.ca/98oct16/EXEC.html Chicken Images http://dailyjournal.tripod.com/nov2002.htm

31. By Tim Styer and Katie Shepard This is an unfinished product!