Outline. Not IF but WHEN: The Threat of Pandemic Influenza. Influenza History

Transcription

1 Not IF but WHEN: The Threat of Pandemic Influenza Michael Olesen Infection Prevention and Epidemiology Abbott Northwestern Hospital Minneapolis, Minnesota Outline History Biology Ecology Sociology Ethics Communications Management References History 2 Influenza History Those who do not remember the past are condemned to repeat it. - George Santayana ( ) History 3 Page 1

2 4 5 Alternative Care Center History 6 Page 2

3 7 History 8 Did 1918 impact St. Cloud, MN? (current population ~ 80,000) Burials at Assumption/Calvary Cemetaries by Year History 9 Page 3

4 History 10 History 11 History 12 Page 4

5 History 13 History 14 History 15 Page 5

6 Comparison to US Baseline History 16 Attack Rates Influenza Low: 15% Louisville High: 53% San Antonio Mean: 28% Pneumonia: 5.3/ /1000 History USPHS 1919 Survey of 11 Cities (N~113,000) Page 6

7 19 US Population circa 1918 History Year Population Change %Chg ,947,000 1,898, ,049,000 1,511, ,538,000 2,077, ,461,000 1,947, ,514,000 1,306, ,208,000-60, ,268,000 1,307, ,961,000 1,415, ,546,000 1,435, ,111,000 1,886, ,225,000 1,890, History 21 Page 7

8 Human Impact year olds Normally comprise only 10% of deaths from influenza In 1918, accounted for >50% of deaths, primarily among those aged History 22 Form follows function - Louis Henri Sullivan ( ) Biology Lippincott's Magazine, March, Influenza Biology Biology 24 Page 8

9 Pathophysiology Infection of upper and respiratory epithelia Entry of cytokines and killer T cells Capillary dilation Blood/fluids leak into lungs Results in ARDS 40-60% mortality in ICU settings ~100% mortality without critical care support Post mortem lung pathology similar to victims of pneumonic plague or chemical weapons Biology 25 Cause of Death Right heart failure Exhaustion of respiratory muscles Secondary bacterial infection (cilia destroyed) Biology 26 Biology N Engl J Med 352;18 27 Page 9

10 Camp Devens, Mass., Surgical Ward No 16 (Base Hospital) 9/29/1918 These men start with what appears to be an ordinary attack of LaGrippe or Influenza, and when brought to the Hosp. they very rapidly develop the most viscous type of Pneumonia that has ever been seen. Two hours after admission they have the Mahogany spots over the cheek bones, and a few hours later you can begin to see the Cyanosis extending from their ears and spreading all over the face, until it is hard to distinguish the coloured men from the white. It is only a matter of a few hours then until death comes, and it is simply a struggle for air until they suffocate. It is horrible. One can stand it to see one, two or twenty men die, but to see these poor devils dropping like flies sort of gets on your nerves. We have been averaging about 100 deaths per day, and still keeping it up. There is no doubt in my mind that there is a new mixed infection here... they all mean but one thing here Pneumonia and that means in about all cases death. Biology 28 Presentation in chickens Biology 29 Characteristics of pandemic virus Novel, or new, virus H5 subtype has never been seen in humans among those living today Infects humans and causes illness 228 cases/130 deaths (6/20/06 WHO) Human to human transmission Limited, but probability increasing for sustained human-to-human transmission Biology 30 Page 10

11 Influenza Ecology Ecology Pandemic versus today World population 1918: 1.8 billion 2006: 6.5 billion Case Attack Rate: 40% (200M 1B) Global Mortality:1-5% (1918 published estimates, some cities much higher) 1918: million 2006: million (3-15 million in US) Ecology 32 What does 300M deaths mean? St. Paul, MN 287,000 population 250,000 deaths from the December 26, 2004 tsunami Imagine a tsunami of that scale EVERY HOUR for a six week period Ecology 33 Page 11

12 Comparison to SARS SARS Influenza Relatively close Extremely contagious contact for spread Upper respiratory Upper respiratory virus virus concentration concentrations become peaks over one week high two days AFTER onset of BEFORE onset of symptoms symptoms Ecology 34 Ecology in China 1968 Pandemic 790 million humans 5.2 million pigs 12.3 million poultry Today 1.3 billion humans 508 million pigs 13 billion poultry Ecology N Engl J Med 352;18 35 The Ecology of Influenza Ecology Microbiol Rev 1992; 56: J Infect Dis 1997;176(Suppl 1): Page 12

13 Gene Sharing Ecology TONS of poultry are smuggled from China to Vietnam EVERY DAY 39 Page 13

14 Page 14

15 43 44 Fortune atcookie Ecology 45 Page 15

16 Risky Food Sociology Sociology 48 Page 16

17 Societal Impact NY State failure to cover a cough resulted in a $500 fine and up to one year in jail NYC 21,000 orphans Shipyards had 50% absentee rates in the middle of a war Bizarre treatment H 2 O 2 13 patients, 12 died Physician claimed success Rumors Influenza was a biological weapon developed and spread by Bayer aspirin and Germans disguised as clinicians (Public Health Rep 1999;114: ) Dogs carried the virus led to mass slayings in Phoenix Will the internet give credence to other rumors? Sociology 49 Business Impact International travel will come to a halt Organizations need to count on 50% absentee rates during the peak weeks Supply side shortages Increased demand Transportation systems disruption Supplies normally shipped in cargo on passenger flights Sociology 50 Hospital Impact Johns Hopkins closed to all but staff and students NYC nurses kidnapped to care for victims in homes Philadelphia General Hospital 43% of staff required hospitalization (masks/gowns had been required 100% of the time) Volunteers often quit after one day Hospitals had to turn away patients Nurses offered $100 bribes to admit patients (~$1450 in 2006 dollars) Daily death toll exceeded the weekly death toll from all other causes Sociology 51 Page 17

18 International Social Impact Woodrow Wilson Paris Peace Conference Sociology Page 18

19 Male Female Population (millions) Male Female Population (millions) Male Female Population (millions) Page 19

20 Male Female Population (millions) Male Female Population (millions) Male Female Population (millions) Page 20

21 Male Female Population (millions) Male Female Population (millions) Male Female Population (millions) Page 21

22 Male Female Population (millions) Male Female Population (millions) Male Female Population (millions) Page 22

23 Male Female Population (millions) Sociology 69 Page 23

24 Influenza Ethics Ethics 70 Ethics of a Normal Influenza Season 36,000 excess deaths 110,000 excess hospitalizations $12 billion (direct medical and lost productivity) Why don t we mandate annual influenza vaccinations for healthcare workers? Ethics 71 Ethics of mandatory vaccination around pandemic influenza Prevention of reassortment Less potential for differential influenza diagnosis (pandemic vs. normal) Maintenance of healthcare workforce Ethics 72 Page 24

25 Chain of Transmission Page 25

26 Page 26

27 Page 27

28 Page 28

29 85 86 Herd Immunity Ethics 87 Page 29

30 Page 30

31 91 92 Flu Vaccination Myth: You have to get naked to get your flu shot. Ethics 93 Page 31

32 Vaccine Production Even though technology has improved (cell culture), methods have not changed (eggs) Ethics 94 Vaccine and Ethics Production time is a minimum of six months before vaccine could become available Current systems would only allow the production of 500 million doses Who should get the vaccine? Example influenza vaccine is less effective in the elderly and immunocompromised. Should vaccine only be given to HCW in LTC settings and visitors be barred during an outbreak or pandemic? Military demand 370,000 doses overseas Ethics 95 Antivirals and Ethics Limited stocks of antiviral medication (WHO recommends enough to cover 25% of population per country) Only oseltamavir (Tamiflu) and zanamivir (Relenza) appear to be effective against H5N1 influenza Individuals are stockpiling oseltamavir Who gets the antivirals? Individual stockpiling prevents accessibility to those that need them during a pandemic Ethics 96 Page 32

33 Antivirals And now you know the rest of the story. Good day. Will antivirals even be available? Amantadine used since the 1990s by poultry farmers in China Knock-off oseltamivir probably also being used illegally to prevent illness in poultry Oseltamavir-resistant strain isolated Nature 437, 1108 (20 October 2005) Current US stockpile is only 4.3 million courses 860, ,000 = 490,000 Precursor molecule for oseltamivir production is only made in China What happens if the borders close? Ethics 97 National Ventilator Surge Capacity and Ethics ~105,000 in US 75,000 80,000 in use at any given time 100,000+ in use during normal flu season Who should get a ventilator? Ethics Osterholm, M. (2005). NEJM 352(18): What is surge capacity? 99 Page 33

34 Military Hospital Surge Capacity Ethics Camp Devens (above near Boston) Built for 1200 Surge capacity: 2500 Census: 6000 Camp Grant (Rockford, IL) Went from census of 610 to 4102 in 6 days The base commander committed suicide 100 Staffing Shortages Caregivers for sick Caregivers for children Community roles The Sick The Statistics The Scared Ethics 101 Meeting the Needs of Pregnant Staff 13 studies indicate the fatality rate of pregnant women during the 1918 pandemic was 23-71% (mean ~ 55%) Most survivors suffered spontaneous abortions Ethics 102 Page 34

35 Influenza Communications Communications 103 Professional Education As late at the mid 80s, medical students in the Honduras were taught that influenza amounted to no more than a bad cold We need to distinguish influenza by removing imprecise terms from our language for other URIs (the flu) and GI illness (the stomach flu) Communications 104 Public Perception of Public Health Messages Communications 105 Page 35

36 Communications 106 Communications 107 Communications 108 Page 36

37 Communications Page 37

38 Key Risk Communication High level of the threat Prevent over-optimistic assessment 1918 Spanish Flu SARS Actions steps for individuals and communities Communications (2004) Peter M. Sandman and Jody Lanard 112 Suggested Messages for Individuals Hand hygiene Do not touch face Appropriate mask use Avoid crowds and gatherings Communications 113 Communications 114 Page 38

39 Cover Your Cough for Vets? Communications 115 Influenza Management Management 116 Mortuary Bottlenecks in 1918 Coffins arriving in Philadelphia needed armed guards Gravediggers refused to dig graves due to decomposed state of bodies Bodies remained in homes for days Sometimes the living shared a bed with the dead Priests had to be recruited to remove bodies from homes 10/10/ recorded deaths in Philadelphia Some morgues at 10x normal capacity Management 117 Page 39

40 Mortuary Bottlenecks Today 8/30/2005 Pima County (Tuscon, AZ) illegal immigrants Management 118 Goods/Services Bottlenecks No one could buy things. Commodities dealers, coal dealers, grocers closed because the people who dealt in them were either sick or afraid and they had reason to be afraid. Management Barry, The Great Influenza 119 Can shortages happen today? Gasoline After onset of military action After Hurricane Katrina Food Will a pandemic trigger a rush to grocers in a similar manner? OTC pharmaceuticals Shelves were emptied in 1918 (Clin Infect Dis 31(6): ) 80% of pharmaceuticals are produced overseas Management 120 Page 40

41 Role of HVAC Systems (Heating, Ventilation, and Air Conditioning) Management Will Droplet Precautions Suffice? Initial guidelines - manage like SARS The diagnosis of avian influenza A (H5N1) was established by isolation of the virus from cerebrospinal fluid, fecal, throat, and serum specimens. The patient s nine-year-old sister had died from a similar syndrome two weeks earlier. In both siblings, the clinical diagnosis was acute encephalitis. Neither patient had respiratory symptoms at presentation. These cases suggest that the spectrum of influenza H5N1 is wider than previously thought. N Engl J Med 2005;352: Page 41

42 Twin Cities Metro Area ~3,000, Extreme times call for extreme measures Management 125 Effective Response The least impacted communities used the most aggressive responses Fairbanks, AK people entering were quarantined x 5 days Only ruthless isolation and quarantine could affect its course. We must be willing to make tough and unpopular decisions to mitigate the impact Management 126 Page 42

43 References 1918 Pandemic History America s Forgotten Pandemic: The Influenza of 1918 by Alfred Crosby Flu: The Story of the Great Influenza Pandemic of 1918 and the Search for the Virus that Caused It by Gina Kolata The Great Influenza: The Epic Story of the Deadliest Plague In History by John Barry References 127 References References Page 43

44 References 130 The Choice Prepare for an H5N1 pandemic nothing happens and be scoffed Fail to prepare pandemic begins, millions die (at least in the short term) 131 Why We Plan History teaches us that everything we do today to prepare for that eventuality will have many lasting benefits for the future. Michael Leavitt Health and Human Services Secretary HHS Pandemic Influenza Plan, Nov Page 44

45 133 Page 45