1. Health Talk on Bird Flu for Airport Community 21 October 2005 S peaker: Dr John Simon

2. What’s All The Fuss About Bird Flu? John Simon Honorary Professor Dept. of Microbiology University of Hong Kong

3. Avian influenza H5N1

4. “The Enemy” Neuraminidase Haemagglutinin Birds N 1-9 H 1-16 Human N1-2 H1-3

5. Human influenza epidemics

6. Influenza Pandemics in the 20th Century In 1957 ‘Asian’ influenza caused more than 1 million deaths In 1968 ‘Hong Kong’ influenza caused more than 1 million deaths In 1918 ‘Spanish’ influenza caused 40 million deaths

7. Influenza Pandemics in the 20th Century A Pandemic today is likely to: Spread rapidly Affect 15-30% of the population of any one country within weeks Span the globe in months (like 1968 pandemic) Have greater socio-economic impact Impact supply chains Not be stopped the way that SARS was.

8. Bird Flu Due to a Type A Influenza H5N1, H9N2, H7N7, H5N2, H7N1 H5N1: ‘Highly Pathogenic Avian Influenza’

9. H5N1 In Poultry South Africa 1961 Hong Kong 1997 China, South Korea, Japan, Vietnam, Thailand, Camodia, Laos, Pakistan, Indonesia, Malaysia 2003-2004 Kazakhstan, Russia (Urals, Siberia) Mongolia, Romania, Turkey 2005

14. H5N1 in Wild Birds Wild Ducks Have No Symptoms Asymptomatic Carriers Bird-fall in Qinghai Migratory Birds Spread It Now a Zoonosis

15. We Had Our Chance Culling Stopped It In HK in 1997 Universal Culling in Vietnam, Thailand & China May Have Stopped It Now It Is A Zoonosis It Is Here to Stay

16. Surveillance of H5N1 viruses in live poultry markets in mainland China Li et al Nature 2004; 430: 209-213

17. I Don’t Know What Will Happen Except To Tell You “We’re Screwed” –Dr Michael Osterholm, Director Center for ID Research & Policy June 2005.

18. Human H5N1 cases and deaths since Jan 2004 CasesDeaths Vietnam9141 Thailand1712 Cambodia44 Indonesia53 Total 11760 The tip of the iceberg

19. Features of H5N1 in Humans Male/Female Ratio 2/3 Age Range 4 Months to 69 Median Age 19. Average Age 24 Case Fatality Rate (CFR) 52% CFR Last 10 Months 39%

20. Transmission To Humans Nasal, Salivary & Fecal Excretions Contact With Contaminated Surfaces Inhalation of Dried Out Feces Eating Undercooked Viremic Birds Drinking Ducks’ Blood

21. Human-To-Human Transmission Currently Inefficient Only One Likely Case (Thailand 2003) Requires Very Close Contact Efficent Transmission  Pandemic Requires Virus Mutation

22. The origin of influenza pandemics

23. How may a H5N1 pandemic virus arise? It happened with SARS It happened with the 1918 “Spanish flu”

24. Will A Pandemic Occur? Yes: As They Have Occurred Over Many Centuries Past Can’t Say When: Next Month, Next Year? Can’t Say If It Will Be H5N1 or Another

25. Why it is likely that H5N1 will be the next pandemic virus? Endemic across a wide geographical area Repeated (thousands) opportunities for infecting humans Repeated inter-species transmission to mammals and to humans Potential for reassortment in pigs or in humans

26. So What’s The Fuss A pandemic virus could be due to recombination (reassortment) or gradual mutation with a direct jump from birds to humans. The latter is likely to be more severe than the former H5N1 mutation allowing efficient human-to- human transmission may not be less severe a clinical illness in humans than it currently is and might parallel the severity seen in the 1918 pandemic

27. Incubation Unknown. Probably Less Than 1 Week “Ordinary Flu” 1-4 Days

28. Clinical Course “Ordinary Flu”: Fever, Cough, Muscle Pain, Headache, Sore Throat “Cytokine Storm” Pneumonia, Respiratory Distress Multi-organ Failure, DIC

29. Treatment Supportive Therapy Mechanical Ventilators Antiviral Drugs (Relenza or Tamiflu) Relenza: Inhalation. More difficult to use but as effective as Tamiflu

30. Tamiflu Must start within first 48 hours Preferably within first 24 hours Dose 1 capsule (75mg) twice daily 5 days Suspension form available for children Active against all types of influenza A Some partial resistance H5N1 noted No guarantee it will be effective !

31. Tamiflu as a Prophylaxis 1 Capsule Daily for –Contacts of known cases –Those involved in culling –In pandemic situations? How long

32. Tamiflu Not available: Indonesia, India, Pakistan Cost for a packet of 10 capsules varies US$25-60

33. Vaccine Sanofi-pasteur trials successful Probably ineffective against mutant Will need to rapidly make new vaccine However current process is very slow Will take 6 months to develop You are unlikely to get the vaccine Slow to make. Only small quantities

34. Effects of a Pandemic Total disruption of travel and business International borders will close Schools, cinemas, restaurants close Hospitals cannot cope Shortage of ventilators Up to ?? 50 million may die Friends, colleagues, family will die

35. What Needs to be Done? Control the outbreak in poultry Early warning of human-to-human spread Pandemic preparedness and logistics Antivirals Vaccines: logistics of production

36. Problems with Control in Poultry Backyard flocks

37. Problems with Control in Poultry “wandering ducks” and “Trojan horses”

38. Problems with Control in Poultry Live poultry markets

39. Can We Stop A Pandemic Theoretically Yes (“Nature”, “Science”) Need to Identify Early Clusters Social Isolation Blanket Tamiflu Reduce Ro In My Opinion “No!”

40. So What Shall We Do? Prepare for a Pandemic Governments to Stockpile Tamiflu Individuals to Purchase Own Supplies Corporations to Make Contingencies Get “Ordinary Flu” Vaccination Educate

41. Transmission of influenza viruses 5 Infectious from 24-48 hrs before symptoms Infectious until 7-8 days after onset of disease, or longer Asymptomatic infection may transmit Large droplets: short range ?? Aerosols: long range Contaminated hands? Surfaces?

42. Possible interventions: Hand hygiene: facilities available in workplace Masks –Recommended for those with symptoms –For those in “ person-contact ” occupations –Education on how to use and dispose of a mask. –Doubtful benefit for general community ‘ Increase “ social distance ” –Closure of schools and public places –Stop public gathering –Curtailing non-essential activities and services –Curtail non-essential domestic travel Reduction of other viral respiratory infections during SARS

44. Websites www.cdc.gov/flu/avian/index.htm www.who.int/csr/disease/avian_influenza/en/ www.info.gov.hk/dh/diseases/influenza/influenza.htm www.wpro.who.int/avian/

45. Summary An H5N1 Pandemic Will Occur Many Millions Will Die Do Not Expect To Get A Vaccine Tamiflu or Relenza May Work. Get It Now!

46. Oh! It’s just the flu

47. Acknowledgment Professor Malik Peiris University of Hong Kong for use of some of his slides

48. Response Measures Alert Response Level Serious Response Level Emergency Response Level Owner Influenza vaccinationSee Notes *HRD Temperature screening, health declaration  TBU Staff education  HRD / SSEPS / CS Airport staff temperature monitoring  All BU / SU Encourage restaurants to provide serving utensils  RAB Maintain close contact with Department of Health  SSEPS / TBU Maintain an adequate supply of personal protection equipment, i.e. face masks, disinfectants, etc  HRD/TSP Step up cleaning and disinfection of public installations  TBU Provide adequate facilities and cleaning materials for hand- washing  TBU Case Reporting  All BU / SU Step up maintenance on indoor ventilation system  TSP Adequate equipment for protecting frontline staff  TSP Restrict Access to Critical Operational Control Centers  TBU / ABU / TSP / MIT Staggered work deployment  TBU / ABU / TSP / MIT Minimize large meetings  All BU / SU *To lower the possibility of misdiagnosing cold and flu with avian flu