Transcript Pandemic Influenza

WWU
Broad View
Pandemic Influenza
Fall 2006
Appreciation
• Materials in this program were modified
from March 2006 information from the City
of Bellingham, courtesy of Fire Chief Bill
Boyd
• Some materials were excerpted from a
June 23, 2006 National Safety Council
presentation by the Centers for Disease
Control
Information Provided
• Influenza characteristics, symptoms and
transmission
• Pandemic influenza characteristics and
current status
• Impacts and historical evidence from
previous pandemics
• Control and prevention for individuals,
households and at WWU
• How WWU is preparing
Influenza
• Contagious disease caused by RNA virus
• Primarily affects the respiratory tract
• Can cause severe illness and lead to lifethreatening complications
• Global infectious disease threat
• Annual public health problem
Transmission:
How Influenza Spreads
• Contact with respiratory secretions from
an infected person via
– Coughing or Sneezing
– Touching respiratory droplets on:
– Self, another person or object
**** THEN *****
• Touching one’s mucous membranes
– Eyes, mouth, nose
– Without washing hands
Seasonal Influenza Information
• Incubation period: 1 to 5 days from
exposure to onset of symptoms
• Communicability: Maximum 1-2 days
before to 4-5 days after onset of
symptoms
• Timing: Peak usually occurs December
through March in North America
Influenza Symptoms
Rapid onset of:
– Fever
– Chills
– Body aches
– Sore throat
– Non-productive cough
– Runny nose
– Headache
Average Influenza Impact in U.S.
• Over 200,000 hospitalizations per year
• About 36,000 deaths per year
• Substantial economic impact
– Lost work and school days
– Estimated $37.5 billion in costs
(CDC information from National Safety Council)
Seasonal Influenza is a Serious
Illness
Who is at greatest risk for serious
complications?
– Persons 65 and older
– Persons with chronic diseases
– Infants
– Pregnant women
– Nursing home residents
Comparison of Pandemic and
Seasonal Influenza
• Seasonal caused by subtypes of influenza
viruses to which people have been
previously exposed
• Pandemics caused by subtypes to which
– People have never been previously exposed
OR
– People have not been exposed for a very long
time
Defining Pandemic Influenza
Global outbreak with:
– Novel virus - all or most people
susceptible
– Readily transmissible from person to
person
– Wide geographic spread
Influenza Viruses
• Subtype based on surface glyco-proteins
– 16 different hemaglutinins (H)
– 9 different neuraminidases (N)
• Human types: H1N1, H3N2
• Current avian: H5N1
• RNA viruses mutate very vigorously
Impact of Past Influenza
Pandemics
Pandemic
Excess
Mortality
Populations Affected
1918-19
(A/H1N1)
1957-58
(A/H2N2)
1968-69
(A/H3N2)
1977-78
(A/H1N1)
500,000
Persons <65 years
70,000
Infants, elderly
36,000
Infants, elderly
8,300
Young (persons <20)
Severe vs Moderate
Moderate
1957-like
Severe
1918-like
Illness
90 million (30%)
90 million (30%)
Outpatient medical
care
Hospitalization
45 million (50%)
45 million (50%)
865,000 (1%)
9,900,000 (11%)
ICU Care
128,750 (0.1%)
1,485,000 (1.7%)
Mechanical
Ventilation
Deaths
64,875 (0.07%)
745,500 (0.8%)
209,000 (0.2%)
1,903,000 (2.1%)
Pandemic Influenza: 2nd waves
• 1957: second wave began 3 months after
peak of the first wave
• 1968: second wave began 12 months after
peak of the first wave
Close Calls: Avian Influenza
Transmitted to Humans
1997:
H5N1 in Hong Kong
18 hospitalizations and 6 deaths
1999:
H9N2 in Hong Kong
2 hospitalizations
2003:
H5N1 in China
2 hospitalizations, 1 death
H7N7 in the Netherlands
80 cases, 1 death
(eye infections, some respiratory symptoms)
Avian Influenza Poultry
Outbreaks, Asia, 2003-04
Human Cases as of March 2006
H5N1 Poultry Influenza
Current Outbreaks (as of Feb 2006)
• Africa: Niger Nigeria
• East Asia & the Pacific: Cambodia, China, Hong Kong,
(SARPRC), Indonesia, Japan, Laos, Malaysia, Mongolia,
Thailand, Vietnam
• Europe & Eurasia: Austria, Azerbaijan, Bosnia &
Herzegovina (H5), Bulgaria ,Croatia, France, Germany,
Greece, Italy, Romania, Russia, Slovak Republic,
Slovenia, Switzerland (H5), Turkey, Ukraine
• Near East: Egypt, Iraq, (H5) Iran
• South Asia: India
Location of Human cases – H5N1
• East Asia and the Pacific:
–
–
–
–
–
Cambodia
China
Indonesia
Thailand
Vietnam
• Europe & Eurasia:
– Turkey
• Near East:
– Iraq
Avian Influenza High Concerns
• Has caused severe disease in humans
who have been infected
• Limited human-human transmission has
occurred in Asia
• Could evolve to be readily transmissible
between humans
• No vaccine for humans is available
• Limited supply of expensive antiviral
medicines
“The pandemic clock is ticking, we just don’t
know what time it is”
E. Marcuse
Historical Review of Pandemic
• 1918-19 is selected because
– Severity of disease
– Enormous impact on society
The 1918 Influenza
Pandemic
America’s Forgotten Pandemic
by Alfred Crosby
“The social and medical importance of the 19181919 influenza pandemic cannot be
overemphasized.
It is generally believed that about half of the 2
billion people living on earth in 1918 became
infected. At least 20 million people died.
In the Unites states, 20 million flu cases were
counted and about half a million people died. It is
impossible to imagine the social misery and
dislocation implicit in these dry statistics.”
America’s deaths from influenza were
greater than the number of U.S. servicemen
killed in any war
Thousands
900
800
700
600
500
400
300
200
100
0
Civil
War
WWI
1918-19
Influenza
WWII
Korean
War
Vietnam
War
Influenza Control Measures
• Vaccines
• Anti-viral medicines
• Preventing transmission
– Infection control
• Preventing contact
– Social distancing
Preventing Transmission
Infection Control
• Hand hygiene
• Face masks for symptomatic persons
• Isolation of ill people and quarantine of
those exposed
Preventing Contact
Social Distancing
•
•
•
•
School closures
Cancellation of public gatherings
Deferring travel to involved areas
Providing alternatives to face-to-face
contacts at work and in other venues
• Increasing distances between people over
3 feet
• Decreasing contact between people
Influenza Control: Quarantine
• Challenges
– short incubation period for influenza
– a large proportion of infections are
asymptomatic
– clinical illness from influenza infection is non
specific
• Not used during annual epidemics
• Could potentially slow onset of a pandemic
before sustained person-to-person
transmission has been established
Medical Care during an
Influenza Pandemic
• Surge capacity of the hospital system is
limited
• Challenges:
– Magnitude and duration
– Staff shortages
– Limited ability to call in external resources
U.S. HHS Doctrine: Save Lives
U.S. Health & Human
Services Department:
• Slow spread,
decrease illness and
death, buy time
• Lowers the peak
burden on medical
infrastructure
• Diminishes overall
cases & impacts
No Intervention
Intervention
Pandemic Flu Today
Despite . . .
– Expanded global and national surveillance
– Better healthcare, medicines, diagnostics
– Greater vaccine manufacturing capacity
New risks:
–
–
–
–
Increased global travel and commerce
Greater population density
More elderly and immunosuppressed
More daycare and nursing homes
On-line resources
•
•
•
•
•
www.pandemicflu.gov
www.cdc.gov/business
www.doh.wa.gov/panflu/
www.dhhs.gov/nvpo/pandemics/
www.wwu.edu/depts/ehs/pandemic.shtml
How WWU is Preparing
• Pandemic Policy approved
• Pandemic response plan being
developed
• Web page available
• Exercise conducted August 2006