Local and Global Public Health Links: Preparation for an Influenza Pandemic

1. Local and Global Public Health Links: Preparation for an Influenza Pandemic Nicole J. Cohen, MD, MSc Chicago Department of Public Health The University of Chicago’s Summer Institute for Educators June 29, 2006

2. Influenza Virus • Three types of influenza virus: A, B, C • Only influenza A and B viruses cause significant disease and epidemics in humans

3. Influenza A Viruses • Classified into subtypes based on two surface proteins, hemagglutinin (HA) and neuraminidase (NA) • 16 HAs and 9 NAs in total • Currently in humans: • H1N1 • H3N2

4. Influenza A Susceptible Hosts

5. Influenza B Viruses • No subtypes • Infect humans almost exclusively

7. Avian Influenza • Infection of bird with influenza A virus • Different strains from the ones that cause human infections annually • Occurs naturally • High vs low pathogenicity viruses • Highly contagious among bird populations • Usually spread from wild birds to domestic poultry • May be carried by birds without causing disease • May cause severe illness and/or death among birds • Rarely infects humans

8. Symptoms of Avian Influenza in Humans • Wide range of symptoms depending on type of virus • Typical flu symptoms (fever, cough, sore throat, muscle aches) • Conjunctivitis (eye infection) • Viral pneumonia • Severe respiratory illness • May be life threatening

9. H5N1 Influenza Virus • 1996 First identified in a goose in China • 1997 First human cases in Hong Kong • 18 confirmed cases, 6 deaths • 150 million chickens slaughtered to control outbreak • 2/2003 Two cases in a Hong Kong family who traveled to mainland China

12. Azerbaijan Cambodia China Djibouti Egypt Indonesia Iraq Thailand Turkey Viet Nam Current Situation Human Cases -- June 20, 2006 228 Cases 130 deaths Death rate approximately 50%

15. How avian influenza infects people • Virus present in respiratory secretions and feces of infected birds • Human infection has resulted from • Close contact with infected birds • Contact with or consumption of raw poultry products • Contact with contaminated surfaces (feces) • Generally has not spread from person to person • Has been suggested in several small family clusters after extremely close contact with sick person • Has not spread beyond one person • Has not spread to health care workers

17. How human influenza spreads • Respiratory droplets • Coughing, sneezing • Spreads through close contact (less than 3 feet) • Prevent by “covering cough”, wearing masks in medical situations • Hand contamination then touching eyes, nose, or mouth • Direct contact e.g. shaking hands with infected person • Contact with objects contaminated by influenza viruses (e.g. doorknobs, phones) • Prevent by hand hygiene, gloves in medical situations

18. H5N1: Is there a vaccine? • A vaccine against H5N1 is under development • Not commercially available • Annual influenza vaccine does not protect against H5N1

19. H5N1: Is treatment available? • Most H5N1 viruses are resistant to older class of antivirals (amantadine and rimantadine) • May be treated with newer antivirals Tamiflu® or Relenza® • Effectiveness is not known • Some resistance to Tamiflu® has been identified

20. Advice for Travelers • CDC has not recommended that the general public avoid travel to any of the countries affected by avian influenza • Receive routine flu vaccine (if available) prior to departure • If traveling to any country with a known outbreak of H5N1 influenza • Avoid poultry farms • Avoid contact with animals in live food markets • Avoid contact with any surfaces that appear to be contaminated with feces from poultry or other animals

21. Advice for Travelers • Practice careful hand hygiene, especially after handling raw poultry • It is safe to eat poultry or eggs that have been properly handled and cooked • Monitor your health for 10 days after returning • Seek medical attention if symptoms of fever or respiratory illness develop

23. Pandemic Influenza • Worldwide outbreak of a novel (new) influenza virus • Occurs infrequently and at irregular intervals • Unpredictable • Potential for substantial impact • Morbidity (illness) and mortality (death) • Social disruption • Economic costs

24. 20th Century Influenza Pandemics • 1918-1919: “Spanish Flu” (H1N1) • > 500,000 US deaths • > 20 million deaths worldwide • 1957-1958: “Asian Flu” (H2N2) • 70,000 US deaths. • 1968-1969: “Hong Kong Flu” (H3N2) • 34,000 US deaths

25. Influenza Pandemic 1918

26. How does a pandemic happen? • 4 factors must be present: • Novel virus • Virus capable of causing disease in humans • Susceptible population • Virus that is transmissible from person to person • Current avian influenza outbreak is not a pandemic

27. Where do new influenza strains come from? • Mixing of human and animal influenza strains • Adaptation of an animal strain to allow person to person spread

28. WHO Pandemic Phases

29. Issues of Concern • Potential rapid worldwide spread due to global trade and international travel • Medical resources may be insufficient • Medical personnel at high risk of infection • Pandemic would likely be prolonged • Community infrastructure disruption • Major economic impact

30. Estimated Impact of “Medium-Level” Pandemic, US • As much as 35% of population could be affected • ~ 47 million people • As many as 734,000 hospitalizations • As many as 207,000 deaths • Economic impact could range between $71.3 and $166.5 billion

31. On the bright side… • Pandemic influenza planning is occurring at the local, state, national and international levels • Surveillance for new influenza strains in birds and humans is ongoing to allow for early detection • Experience with SARS has led to increased awareness and preparedness to deal with global infectious disease emergencies • Medical care and isolation capabilities are more sophisticated than during 1918

32. Global Public Health Surveillance • International Health Regulations revised 2005 • Defines Public Health Emergency of International Concern (PHEIC) • Contains a decision instrument to help countries determine whether reporting to WHO is necessary • Includes a list of diseases to be reported immediately, even if single case • Encourages countries to consult WHO for events that may be of public health relevance

34. Pandemic Influenza Planning • Goals • Limit total burden of disease (illness and death) • Decrease social disruption • Decrease economic loss • Engage all levels of health care system, public health, and emergency response • Include public and private sectors • Key similarities (and differences) between pandemic response and other health emergencies • Planning, resources, and implementation

35. Local Planning an Influenza Pandemic • Surveillance recommendations • Laboratory recommendations • Antiviral plan • Vaccine distribution plan • Containment including isolation and quarantine issues • Surge capacity, mortuary issues, and mass care • Communications • Public information

36. Vaccine and Antiviral Medications • Vaccine • Will probably not be available in early stages of a pandemic • Even when vaccine does become available, supplies will be limited • Prioritization will have to occur • Antiviral medications • Stockpiled supplies are limited but increasing • Resistance may be a problem • Prioritization will have to occur

37. Controlling a Pandemic • Early identification and isolation of ill people will be critical • Close monitoring and possible quarantine of exposed contacts • Basic infection control measures • “Social Distancing” • Public transportation • Large gatherings/special events • Schools

38. Preventing Spread of Influenza • Preventing illness: • Wash your hands • Stay away from people who are sick • Get your flu vaccine! • If symptomatic with a respiratory illness: • “Cover Your Cough” • Wash your hands! • Don’t visit friends or family in hospital or a long term care facility • If diagnosed with influenza: • Don’t go to work or attend school while symptomatic

39. Corporate (Workplace) Preparedness • Encourage respiratory and hand hygiene in the workplace • Ensure appropriate hygiene supplies and facilities are available • Discourage employees diagnosed with influenza from working while symptomatic • Plan for functioning with high levels of absenteeism • Mechanisms for employees to work from home, if possible

40. Preparedness in Schools • Hygiene messages/posters • Disease surveillance • Systematic exclusion of sick students and staff • Consider the possibility of school closures • Who makes this decision? • Mandatory closures vs self-shielding behaviors • Continuity of education

43. Personal/Family Emergency Preparedness • Prepare a disaster supply kit for 3 days (general emergencies) • Create a Family Emergency Plan • Know where to access accurate information

44. Personal and Corporate Antiviral Stockpiles – A Bad Idea!!! • Depletion of resources from the public sector • Inadequate supplies for treatment and prophylaxis during seasonal influenza outbreaks • Potential for misuse (wasting) during non-influenza respiratory infections • Potential for development of resistance • Incomplete courses, incorrect dosing, sharing • Cost • Inequitable distribution of drug • Shelf life/expiration

45. For more information • http://www.cdc.gov/flu/avian/ • http://www.who.int • http://pandemicflu.gov/