Powerpoint slides, "Pandemics Happen"

Download Report

Transcript Powerpoint slides, "Pandemics Happen"

Pandemics Happen
Poudre Valley Hospital TAC
March 21, 2006
Adrienne LeBailly, MD, MPH
Director, Larimer Co. Dept of Health
& Environment
Larimer County in 1918
 County
 Fort
population about 27,000
Collins population 8,700
 Loveland
population about 5,000
Social Environment in 1918
Most residents involved in agriculture,
directly or indirectly
 World War I was the major news story
 There was rationing of coal, fuel, food and
other items needed for war effort
 Red Cross was very active in community,
supporting war effort

Outbreak begins in military
training camps
Deaths occurring in
training camps in East
were reported in local
newspapers
 Numerous Larimer
County enlistees/
draftees were among
the fatalities (4 from
Camp Dix in 1 wk.)

Spreading to Civilians
Larimer County
residents were aware
of growing, alarming
deaths among
civilians in Eastern
cities
 First cases in CO in
Boulder; army
trainees on College
campus. (First cases
in FC at Ag College)

Flu shut down schools and
businesses
Loveland schools
closed on Oct. 8
 Fort Collins closed
schools on Oct. 10

They would not
reopen until
Dec. 30
Headlines from issues of Fort Collins Weekly Courier, 1918
Week
b
b
b
-F
e
8
1
n2
5
2Fe
26
18
11
2
Fe
n
9Ja
-J
an
n
4
2
Ja
n1
12
n
29
21
1
Ja
n
5Ja
-J
a
ec
ec
2
Ja
n
30
-D
-D
14
5
Ja
ec
22
15
7
5
D
ec
ec
-D
ec
30
23
6
3
D
D
ec
87
ec
ov
1D
-N
ov
ov
1
9
3
D
ec
24
-N
-N
ov
2
3
D
ov
17
10
3N
ov
6
N
ov
ov
ov
-2
6
18
N
N
N
7N
20
-1
9
12
4
O
ct
2
13
6-
2
O
ct
O
ct
O
ct
Deaths
Loveland Deaths, Oct 1918-Feb 1919
Flu/Pneumonia Deaths by week
17
16
14
12
10
8
8
5
4
3
2
1
1
0
0
1918 Flu killed young adults

Highest number
of deaths were
in people in their
late teens
through mid 30’s
Pneumonia & Influenza Deaths by Age,
Loveland 1917 & 1918 (Sept-Dec)
18
17
16
16
14
Deaths
12
10
8
7
6
6
5
5
4
2
2
1
0
0
1
1
1
0
1
0
0
0
65-74
over 75
0
0-4
5-14
15-24
25-34
35-44
45-54
55-64
Age in years
1917 (Sept-Dec)
1918 (Sept-Dec)
By the end of the outbreak
 Overall,
there were 67 deaths in
Loveland in a 15 week period.
 Nationwide, over 650,000 people died
in the U.S.
 40-50 million people died worldwide
 Overall in U.S. a 2.5% case-fatality
rate
One Fort Collins physician died from the Spanish Flu
The 1918 Virus

The 1918 virus has been recreated by
sequencing RNA fragments obtained from
pathological specimens in military
museums and from bodies frozen in the
permafrost and reverse engineering the
virus.

We can study this virus and try to
understand why it was so lethal.
Why are we concerned today?
Widespread and spreading prevalence of
avian flu in migratory birds; broad host
range
Continued outbreaks among domestic
poultry
Mammalian infection (cats, pigs, etc.)
often lethal
Current avian flu virus share some
features of 1918 virus, and is evolving
Why we are concerned….
Sporadic human cases (181 reports to
date)
• Most in young and healthy
• Case-fatality >50%
• Rare person-to-person transmission
Sustained and rapid person-to-person
transmission MAY develop, causing a
PANDEMIC.
Influenza Virus types
– Type A: Infects humans and other animals
 More severe illness
 Causes regular epidemics; can cause
pandemics
– Type B: Infectious only to humans
 Causes epidemics, but less severe illness
Influenza Virus

Influenza A is subtyped by surface
proteins
– Hemagglutinin (H)
 16 different types
 Helps virus enter
cells by binding
to sialic acid
– Neuraminidase (N)
 9 different types
 Helps virus leave cell to infect other cells
Influenza Virus
All known subtypes of Influenza A found in
birds - 144 (16 x 9) possible combina-tions
of H’s and N’s
 H5 and H7 cause severe outbreaks in birds
 Human disease mostly due to H1, H2, H3
and N1 and N2.
 The H and N surface proteins are the
targets of antibodies

Influenza Virus
 The
virus has 8 genetic
segments made of
single-stranded RNA,
coding for 10 genes.
 The
virus replicates inaccurately,
leading to genetic variants that
change continually.
Influenza Virus
 New

vaccines needed yearly
Major change in H or N may leave
immune system unable to recognize
new virus
– No immunity in population —potential
for pandemic
Seasonal Influenza
Outbreaks yearly, usually in winter months
 Illness more severe for very young, elderly,
or those with pre-existing health conditions
 Yearly, 5-20% of population get the flu
 Annually causes >200,000 hospitalizations
in US
 36,000 influenza/pneumonia deaths yearly
in US

Transmission of flu virus
Incubation period of 1-4 days for regular
flu - not clear if H5N1 might be longer
 Can be communicable to others 24 hours
before symptoms begin - and up to 5 days
or more after onset (adults) or 10 or more
days (children)
 Usually spread through respiratory
droplets or contaminated objects. May
also be airborne, and perhaps thru feces.

Seasonal Flu vs Pandemic Flu
Seasonal
 Occurs every year
Occurs during winter
(usually Dec-Mar)
 Most recover in 1-2
weeks without tx
 Very young, very old,
ill most at risk of
serious illness





Pandemic
Occurs infrequently
(3-4 per century)
Occurs any time of
year
Some may not
recover, even with tx
People of all ages
may be at risk
Avian Outbreaks
Human Pandemics
Over the past 500 years
 Three
to four pandemics have
occurred per century, although there
is no specific periodicity.
 The
longest period of time between
pandemics is 42 years.
 As
of 2006, it’s been 38 years since
the last influenza pandemic.
Two Ways Flu Viruses Change
 Point
mutations occur in viral RNA
during replication (sometimes called
Antigenic Drift)
 Reassortment
- genetic segments
from two different flu viruses
infecting the same cell swap genetic
segments (sometimes called Antigenic
Drift)
N Engl J Med 2005; 353:2210
N Engl J Med 2005; 353:2210
N Engl J Med 2005; 353:2210
N Engl J Med 2005; 353:2210
How are bird & human influenza
viruses different?

The hemagglutinins (H) of bird vs. human
viruses preferentially attach to different
forms of sialic acid.
Transmissibility vs. Virulence

Hemagglutinins (H) probably play a major
role in the ability of a virus to infect and
be transmitted between humans.

Hemagglutinins may be related to
virulence, but other viral genes are
probably involved as well.
There are
severe pandemics and
mild pandemics
Infectious Disease Deaths 1900’s
Deaths per 100,000 per year
United States, 1900-1996
1957
1968
1918
JAMA.1999; 281: 61-66.
Why did young people die
in 1918?
Over-reaction by the immune system
called “cytokine storm”
 Those with the strongest immune systems
affected
 Older people and youngest often die of
bacterial pneumonia complicating flu -treatable now with antibiotics
 Even in 2006, no good treatment for
“cytokine storm.”

H5N1 Avian Influenza

Hong Kong 1997
– 18 human cases, 6 deaths
– 1.4 million birds destroyed

Reappeared in Asia in 2003
– Human cases in Hong Kong family that had
traveled to China in February
– Outbreaks in birds go undetected/unreported
– Tigers and leopard infected in Thailand
Countries with H5N1

East Asia & Pacific:
– Cambodia, China, Hong
Kong, Indonesia, Japan,
Laos, Malaysia, Mongolia,
Burma, Thailand, Vietnam

South Asia:
– India, Pakistan (H5),
Kazakhstan

Africa:
– Cameroon, Niger, Nigeria

(as of 3/18/06)
Middle East:
– Egypt, Iran, Iraq, Israel,
Turkey

Europe & Eurasia:
– Afghanistan,Albania,
Austria, Azerbaijan, Bosnia
& Herzegovina (H5),
Bulgaria, Croatia, Denmark
(H5), France, Georgia,
(H5), Germany, Greece,
Hungary, Italy, Poland,
Romania, Russia, Serbia &
Montenegro (H5), Slovak
Republic, Slovenia, Sweden
Switzerland, Ukraine
Concern with H5N1 Influenza
Virus mutates rapidly
 Can acquire genes from viruses infecting
other species
 H5N1 has acquired some of genetic
changes in the 1918 virus associated with
human-human transmission
 Causes severe disease in humans
 High fatality rate

Cumulative Number of
Confirmed Human Cases of
Avian Influenza A/(H5N1) Reported
to WHO as of March 16, 2006
Year of Onset
Cases
Deaths
Case fatality rate
2003
3
3
100%
2004
2005
2006
Total
46
95
37
181
32
41
26
102
70%
43%
70%
56%
Influenza vaccines and
treatment
Yearly Vaccine Development
Inactivated trivalent vaccine (killed vaccine)
 2 A, 1 B
 Effectiveness of vaccine depends on “match”
between circulating strains and those in vaccine

2005–2006 Influenza Season
A/New Caledonia/20/99-like
A/California/7/2004-like
B/Shanghai/361/2002-like
Surveillance on
circulating strains
Prior Year
January
Selection of
specific strains
February
March
Preparation
and distribution
of virus stock to
manufacturers
April
Seed pools
inoculated into
eggs
N Engl J Med 351:20 November 11, 2004
May
Harvest and
concentration
of fluids
June
July
Vaccine inactivated
and purified
August
Vaccine blended,
content verified
September
Packaging, labeling,
delivery
October
N Engl J Med 351:20 November 11, 2004
Influenza—Vaccine Production
 Flu
vaccines first produced in 1940s
 2 manufacturers in US for flu vaccine
 80 million doses produced by late
September (about 60 M made in US)
 6-9 months to produce vaccine
Pandemic Vaccine
Inactivated pandemic vaccine would likely
require 2 doses a month apart to provide
full protection
 U.S. doesn’t have the capacity to
manufacture 600 million doses to cover
the U.S. population (currently about 60
million)

Pandemic Vaccine

U.S. Government has contracts to produce
vaccine for 2 H5N1 viruses
– Issues: Small quantity, efficacy, genetic
variants as viruses evolve
Growing viruses in cell cultures rather than
eggs would be faster but still experimental
 Other approaches: Naked DNA vaccines,
other viruses engineered to produce H5N1
antigens, vaccines targeting less variable
antigens

Treatment

Adamantanes (Amantadine and
Rimantidine) probably not useful as most
H5N1 show resistance (as do most
seasonal Influenza A strains this year.)

Neuraminidase inhibitors (Oseltamivir and
Zanamivir) have limited effect on human
flu and must be given in first 48 hours of
symptoms. Efficacy with H5N1 uncertain.
Future treatments?
Drugs that might block cytokine release
which can lead to ARDS
 Drugs that might inhibit genes associated
with virulence
 siRNA’s - short interfering RNA segments
of about 25 nucleotides in length that
might block proteins key to flu virus
replication

The Bottom Line
 Don’t
expect adequate supplies of
effective vaccines or anti-virals if a
severe human influenza pandemic
occurs in the near future.
Are we more or less at
risk today compared to
1918?
Why at LESS risk in 2006
 Antibiotics
for bacterial pneumonia
complications of influenza
 Some antiviral medicines
 IV fluids, oxygen, ventilators
 Greater ability to do surveillance,
confirm diagnosis of flu
Why at LESS risk in 2006
 Rapid
means of communications internet, TV, radio, email
 More effective personal protective
equipment
 Fewer people living in each
household and more rooms.
Why at MORE risk in 2006
A
lot more international travel
 10 times more people in Larimer
County, contact with far more people
daily
 Very little surge capacity in health
care today
 Greater reliance on health
professionals
Why at MORE risk in 2006
 More
elderly and immunecompromised people in population
 Infectious disease deaths uncommon
 Much less self-sufficient than in
1918’s (households and businesses)
 Today’s society not used to rationing,
sacrifice, compared to war-time 1918.
Why at MORE risk in 2006
 Far
more manufactured goods and
raw materials come from distant
areas, especially Asia
 “Just-in-time” ordering of needed
supplies instead of warehousing
critical items on site
Overall, are we at more or less
risk?
 Up
to individuals, organizations,
communities, states, and nations to
decide as they plan for a possible
pandemic
What might happen in a
severe pandemic?
If it happens soon…..
There will be little or no vaccine until
6 - 9 months after the outbreak begins
 There will be very limited supplies of
antiviral medicines for treatment (for 1%
of population, perhaps less).
 All communities hit a about the same time
 We need a plan for the short-term that
assumes no effective shots or Rx

What might occur
 High
levels of absenteeism
 Health system could be overwhelmed
 Essential services could be at risk
(fuel, power, water, food, etc.)
 “Just-in-time” supply lines could be
disrupted
 High mortality rates could occur
 Social disruption could occur
Impact of a severe pandemic on
Larimer County
Assumptions using
Larimer County
Population of
275,000
Health Impact
Number
Total illnesses
41,250 – 96,250
15-35% of
population
Outpatient visits
16,500 – 41,250
6-15% of
population
Hospitalizations
2,062 – 9,625
5-10% of ill
patients
Impact of a severe pandemic on
Larimer County
Health Impact
Number
Assumptions using
Larimer County
Population of
275,000
Hospitalizations
per day at peak of
outbreak
About 25% of all
cases occurring in
peak week
75/day – 350/day
Deaths
412 – 4,812
1%-5% of ill
patients
Deaths per day at
peak of outbreak
15/day - 172/day
(Normal average
4 deaths/day)
About 25% of all
deaths occurring
at peak week
Considerations for
preparedness
Can we maintain our utilities?
 Recent
disasters have showed us the
need for water, power, telecommunications, fuel in an emergency
 Could they operate with 50% of
staff?
 Do they stockpile materials and parts
to ensure operation for 90-120 days?
Will transportation/trade
problems impact food supply?
 Typical
household has food on hand
to last 3 days.
 Few families have emergency
reserves for a prolonged period
 Low-income least able to set supplies
aside for an emergency
 Prices will rise quickly in emergency.
Who will help us?
 Little
or no state and federal assistance
 Local government also limited in what it
can do to assist citizens
 Churches, neighbors, friends and
families would need to help each other
 Vulnerable groups would need extra
assistance
 Advance planning and stockpiling of
necessities would help.
What all organizations can do:
Maintain Essential Services
 Identify
essential activities and redeploy staff if needed to fill vacancies
in critical services.
 Cross
train: Make sure all critical
functions can be done by several
different people.
Maintain Essential Services
 Create
written instructions/
procedures for critical processes that
can be carried out by others
 If
possible, keep essential supplies/
parts stockpiled in advance to
maintain services.
Increase Social Distance
 Determine
how to provide services
with less person-to-person contact
whenever possible
 Increase telecommuting if possible
 Use phone, web, virtual conferences
to replace face-to-face meetings
Decrease contact exposures
 Increase
cleaning/sanitizing of locks/
doorknobs, faucet and toilet handles,
shared keyboards, telephones, other
equipment
 Caution:
vacuuming/sweeping may
stir up infectious particles
Decrease contact exposures
 Use/provide
tissues, hand sanitizers,
disposable gloves if available
(All could be scarce
during a pandemic)
 Increasing
humidity may reduce virus
Provide Personal Protective
Equipment
 Need
will vary with type organization
 Will be difficult to obtain in a
pandemic - need to secure in advance
 Masks (N95 or better) may reduce
exposure, but are difficult to wear for
prolonged time or if employee has
health problems.
Teach protective actions
 Hand
washing without
recontamination
 Covering cough, not using hands
 Avoid putting hands to face, mouth,
nose, eyes.
 Staying home if any signs of illness
Prepare Communications Plan
 How
will key managers communicate
among themselves
 How will information be conveyed to
customers?
 How will information be conveyed to
employees?
Prepare for difficult HR issues
 If
offices are closed, will staff be paid?
 If staff are needed, can they refuse to
come to work?
 If required to report, what protective
equipment, if any, will be provided?
 Can employer force someone who may
be ill NOT to work? (Employees without
sick leave may try to work while ill.)
Prepare for difficult HR issues
 If
an employee is required to work
with ill people and becomes ill, is it
a worker’s comp situation?
Hospital Issues
 Train
all staff about pandemic
influenza and their role if it occurs
 Encourage workers to prepare their
homes and families so staff can be
available to provide care
 Involve all key hospital functional
units in pandemic planning efforts
Hospital Issues
 Surveillance/reporting
of flu cases
 Plans for dealing with shortages of
personnel, supplies, medicines,
ventilators
 Surge capacity
 Triage plan for admissions, ICU beds,
ventilators
 Isolation of flu patients from other pts.
Hospital Issues
 Coordination
with other hospitals
 Internal and external communications
 Mental health needs of workers,
patients and family members
 Prioritized use of limited anti-virals
 Enhanced environmental controls and
sanitizing
Hospital Issues
 What
happens when ER or hospital is
overwhelmed?
 Alternative triage by phone or
through special triage centers?
 Alternative care centers?
 How could these be staffed?
How Ready Are We?
Used with permission of the Minneapolis Star-Tribune
Take home messages
You don’t know if the pandemic will start
tomorrow, a year from now, or ten years
from now, or how severe it will be.
 Don’t
assume it’s tomorrow and distort
your life unbearably.
 Don’t
imagine it’s never and postpone
your preparations indefinitely.
from Peter Sandman, Risk Communications Specialist
Take home messages

Bird or Avian flu
Pandemic Flu

We could have avian flu cases in humans
here sporadically as is occurring in other
parts of the world.
That is NOT a pandemic, but will likely
raise fears and stimulate efforts to prepare
for one.
Take home messages

Preparations for a severe pandemic should
be made, NOT because we know one is
imminent, but because the cost of being
unprepared is unacceptable.
If we wait till a pandemic is imminent, it
will be too late to prepare.
(Hoping for the best is good, but is not an
adequate plan.)

Take home messages

We can’t stop a pandemic, but we can
lessen the harm by planning and
preparing
Unprepared
Impact
Prepared
Weeks
"Every day a pandemic
doesn't happen
is another day
we have to prepare.”
--Michael Osterholm