Pandemic Influenza

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Pandemic Influenza

• John Wilgis, MBA RRT
• Florida Hospital Association
• Director, Emergency Management Services

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• Is it here yet?

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Influenza Definitions

• Seasonal Flu
• Respiratory illness that can be transmitted
  person to person. Most people have some immunity,
  and a vaccine is available.
• Avian Flu
• Caused by influenza viruses that occur naturally
  among wild birds. Low pathogenic is common in
  birds and causes few problems. Highly pathogenic
  H5N1 is deadly to domestic fowl, can be
  transmitted from birds to humans, and is deadly
  to humans. There is virtually no human immunity
  and human vaccine availability is very limited.
• Pandemic Flu
• Virulent human flu that causes a global outbreak,
  or pandemic, of serious illness. Because there is
  little natural immunity, the disease can spread
  easily from person to person. Currently, there is
  no pandemic flu.

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Influenza Differences

• Seasonal Pandemic
• Yearly Rarely
• Familiar virus New virus
• Mild/moderate Severe symptoms
• symptoms
• Very young, very old, Healthy people
• health problems
• Vaccine available No vaccine

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Human Influenza

• Seasonal influenza
• Three types A, B, and C
• Three influenza viruses currently circulate
  worldwide
• 2 type A strains (currently H1N1 and H3N2)
• 1 type B strain
• Adults may have partial immunity (protection) to
  seasonal flu
• Have had past infections with related flu
  viruses
• No pre-existing immunity to a new virus that is
  dramatically different from past viruses

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Human Influenza Transmission

• Influenza spreads readily from person to person
• Primarily thought to spread by respiratory
  droplets
• Lesser role for airborne spread and indirect
  contact
• May be transmitted from infected persons who
  appear well (asymptomatic trans)
• Short incubation period average 2 days (range
  1-4 days)
• May be spread 24 hours before onset of symptoms
  and during the symptomatic period

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Avian Influenza A (H5N1)

• Why are we so concerned about Avian Influenza A
  (Bird flu, H5N1)?
• Unprecedented dissemination in birds
• Direct spread from domestic birds to humans
• Strains (2003) resistant to amantadine and
  rimantadine possibly oseltamivir
• Threat of human pandemic

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What Do the H and N Mean?
Proteins on the surface of the virus
Neuraminidase (NA) (9 types exist in nature)

• Hemagglutinin (HA)
• (16 types exist in nature)

Genes
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Epizootiology - Birds

• Natural Hosts
• Domestic fowl, ducks, geese, turkeys, guinea
  fowl, quail, and pheasants
• Source of Infection
• Generally not ascertained
• Direct/indirect contact with migratory waterfowl
• Spread
• Rapid in flocks by direct contact
• Viral shed in feces and nasal and ocular
  discharges

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H5N1 History and Evolution
Key epidemiological findings

• Nomadic or free-range ducks
• Contact wild waterbirds
• Virus shedding and spreading
• Reservoir of infection
• Live bird markets
• Cultural practices

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Exposure to Avian Influenza
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Exposure to Avian Influenza
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Current Outbreak Avian Influenza A (H5N1)

• All cases involved close contact with infected
  poultry or ill family members.
• No sustained person-to-person transmission.
• Mortality rate is high in human avian flu
  infections.
• Remains very difficult for humans to get.
• Is still a disease of birds.

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Current Outbreak Avian Influenza A (H5N1)

• Human Deaths
• 385 cases, 243 deaths (63.1 Case Fatality Rate)
• 15 countries
• Bird Deaths
• 150 200 million bird deaths
• gt50 countries (Asia, Europe, Africa)

WHO, 19 June 2008
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Current OutbreakAvian Influenza A (H5N1)

• There is NO current human influenza pandemic
• The US and many other countries are preparing for
  a possible severe influenza pandemic because
• The avian influenza (bird flu) outbreak is
  widespread and not able to be controlled.
• The virus can infect humans and cause severe
  illness.
• An avian influenza virus evolved to cause a
  catastrophic human pandemic in 1918.

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Pandemic Threat

• Three Requirements for a Pandemic
• Novel virus -- no immunity in human population
• Virus infects humans causing serious illness
• Sustained person-to-person transmission

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Pandemic Influenza

• A new strain of influenza can evolve
• When an avian virus mutates or changes.
• From a combination of an avian and human virus.
• If the new strain infects humans and is able to
  spread easily from person to person
• Humans would have little or no immunity.
• It would rapidly travel around the world and
  cause high levels of disease and death.
• Pandemic global outbreak of disease
• Occur naturally at variable intervals.
• Are not always severe.

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Origins of Pandemic Influenza
Belshe RB. N Engl J Med. 2005 3532209-11
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20th Century Influenza Pandemics

• 1918-19 Spanish flu A (H1N1)
• Most severe pandemic known.
• New influenza virus subtype emerged and spread
  around the globe in 4 - 6 months.
• 20-50 million deaths worldwide.
• 500 - 650,000 deaths in the U.S.
• Ten times as many Americans died of influenza
  than died in World War I.

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20th Century Influenza Pandemics

• 1957-58 - Asian flu A (H2N2)
• First identified in China in late Feb 1957.
• Spread to the U.S. by June (4 months).
• 70,000 deaths in the U.S.
• 1968-69 - Hong Kong flu A (H3N2)
• Detected in Hong Kong in early 1968.
• Spread to U.S. later that year.
• 34,000 deaths in the U.S.
• H3N2 continues to circulate.

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Influenza Pandemics Summary

• Pandemics vary in severity.
• Not possible to predict in advance how severe the
  next pandemic will be, but we know from history
  that they can be severe.
• Not possible to know in advance when the next
  pandemic will occur.
• When it does occur, it will spread rapidly.

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National Strategy

• Stop, slow or otherwise limit the spread of a
  pandemic to the United States.
• Limit the domestic spread of a pandemic, and
  mitigate disease, suffering and death.
• Sustain infrastructure and mitigate impact to the
  economy and the functioning of society.

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U.S. Planning Assumptions

• Attack rate 35 of population
• Treatment rate 25 of population
• Hospitalization rate 10 of cases
• Case fatality rate 2 (2 - 50)
• Pre/asymptomatic 30 - 50 (?)
• transmission
• Reproduction number 2 people (0 21 people)
• Incubation period 2 days (1 8 days)

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HHS Assumptions
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HHS Assumptions
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SC DHEC Assumptions

• Infection rate
• Ranging from 15 to 30
• Outpatient care
• 500,000 1.200,000
• Hospitalizations
• 7,000 - 17,000
• Deaths
• 2,000 5,000

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Outbreak Control Tools

• Infection control
• Isolation
• Quarantine
• Social distancing
• Sheltering in place
• Antivirals
• Vaccines

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Phases, Stages and Categories

• Phases (WHO)
• Global Risk.
• Stages (US Government Response)
• Immediate and specific threat a pandemic virus
  poses to the US population.
• Categories (HHS/CDC)
• Severity index (think hurricanes).

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WHO Phases
(WHO. 2007)
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US Stages
(CDC. Feb 2007)
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CDC Severity Index
(CDC. Feb 2007)
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Human Influenza Vaccine

• Influenza virus is continually changing
• Allows virus to evade the immune system.
• Flu vaccine must be made yearly
• Based on best projection of the types of
  influenza virus that will be circulating.

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Human Influenza Vaccine

• Vaccination is one of the most effective ways to
  minimize suffering and death from influenza.
• Research has developed a vaccine for one strains
  of the H5N1 influenza virus in humans.
• The US Government is working to expand domestic
  influenza vaccine production capacity.
• However, the scarcity of pre-pandemic and
  pandemic influenza vaccine will require that the
  limited supply be allocated or prioritized for
  distribution and administration.

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National Strategy - Vaccines
(CDC. Feb 2007)
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Antivirals

• Relenza (zanamivir)
• FDA Approved for
• Persons aged 7 years and older for treatment of
  uncomplicated influenza illness.
• Treatment of type A and B influenza.
• Preventive use, to decrease the risk of
  developing influenza illness, for persons aged 5
  and older.
• For the drug to be effective, treatment needs to
  be started within two days of the onset of
  symptoms.
• An inhaled powder.
• Relenza is not recommended for people with
  underlying respiratory disease.
• Relenza is not a substitute for influenza vaccine.

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Antivirals

• Tamiflu (oseltamivir phosphate)
• FDA approved for
• The treatment of uncomplicated influenza in
  patients one year and older whose flu symptoms
  have not lasted more than two days.
• Approved to treat Type A and B influenza.
• Also approved for the prevention of influenza in
  adults and children aged one year and older. 
• Oral administration
• Efficacy of Tamiflu in the treatment of influenza
  in subjects with chronic cardiac disease and/or
  respiratory disease has not been established.

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Human Influenza Vaccine

• A tiered allocation for vaccines in severe
  pandemics is being proposed with the following
  objectives considered to be the most important
• Protect those who are essential to the pandemic
  response and provide care for persons who are
  ill.
• Protect those who maintain essential community
  services.
• Protect children.
• Protect workers who are at greater risk of
  infection as a result of their job.
• Protect those who maintain homeland and national
  security.

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Vaccine Allocation
(DHHS. DHS. 23 July 2008)
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Vaccine Allocation
(DHHS. DHS. 23 July 2008)
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Vaccine Allocation
(DHHS. DHS. 23 July 2008)
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Key Strategy
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Healthcare Planning

• Clinical Care
• Communications
• Leadership
• Operations
• Legal
• Employee Health

• Psychosocial
• Human Resources
• Logistics
• Supply Chain
• Finance
• Ethical

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On-Going Planning Issues

• Community Interventions
• Hospital Planning Support
• Alternate Medical Treatment Sites
• Altered Standards of Care

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Building a Pandemic Plan ? Recovery
Build Pandemic Response Plan
Stabilize Operations, Recover and Prepare for
Next Wave
Activate Plan and Manage Problems
Communicate and Exercise
Monitor
Inter-Pandemic Period
Pandemic Alert Period
PANDEMIC PERIOD
Time Between Waves
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Post Test

• How Does Your Community Plan To Address The Needs
  Created By An Influenza Pandemic?
• Call in FEMA
• We Have No Plan
• We Have Created A Plan Specifically For Avian
  Influenza
• Not Sure

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Post Test

• How Does Your Community Plan To Address The Needs
  Created By An Influenza Pandemic?
• Call in FEMA
• We Have No Plan
• We Have Created A Plan Specifically For Avian
  Influenza
• Not Sure

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Q A

• Thank You!