CDC Meeting on Community Mitigation of Pandemic Influenza
Nearly all slides are from Presentations made at the Stakeholders
Meeting Community Mitigation During Pandemic Influenza in the US
Atlanta, GA December 11-12, 2006
Slide 2
What actions should we take in a pandemic? Mandatory or
voluntary? Which combinations of actions? In what order? At what
point in the outbreak? What evidence is there that these actions
will work?
Slide 3
Potential Tools in Our Toolbox Our best countermeasure vaccine
will probably be unavailable during the first wave of a pandemic
Antiviral treatment may not be available in sufficient quantities.
The effectiveness of antiviral treatment is not clear.
Slide 4
Some Possible Actions Reporting of cases Isolation of Sick
Quarantine of contacts Closing schools Restrictions/curfew on
children/teens Closing facilities where people gather Increased
sanitizing and PPE Social distancing of adults in workplace
(liberal leave, tele- commuting, shifts) Closing non- essential
offices Vaccine/antivirals when if available
Slide 5
Purpose of Community-Based Interventions 1. Delay outbreak peak
2. Decrease peak burden on hospitals/ infrastructure 3. Diminish
overall cases and health impacts Daily Cases #1 #2 #3 Days since
First Case Pandemic outbreak: No intervention Pandemic outbreak:
With intervention
Slide 6
Of these options, what will we do and when?
Slide 7
Researchers taking two approaches to study effectiveness
1.Modeling influenza outbreak using mathematical tools 2.Looking
back at data from 1918 to look for evidence that certain
interventions worked.
Slide 8
Different actions may be taken in a severe pandemic compared to
a milder one
Slide 9
Epidemiology Drives Approach ILI and/or sick family members
Influenza-like illnessConfirmed influenzaLiberal leave policies
Aggressive social distancing Social distancingEncourage good
hygiene Workplace protections Encouraged + selective closures
EncouragedHigh-risk individualsCommunity social distancing
ChildrenHigh-risk individuals Protective sequestration
ProactivePunctuatedReactiveSchool Closure YesHigh-risk individuals
Prophylaxis Yes???NoQuarantine Yes Treatment Yes Isolation 0.5%0.1
- 0.5% 0.1%Case Fatality Rate SevereModerateMild SAMPLE
Slide 10
What some models tell us about actions to reduce pandemic flu
spread
Slide 11
Value of combining strategies Longini model
Slide 12
Value of combining strategies Glass model
Slide 13
What do the Modeling Results Mean? Not proof of efficacy or
effectiveness, BUT offer reason for optimism regarding non-
pharmaceutical interventions Suggest that maximal effectiveness
will be achieved by appropriate targeting of intervention and
timing (early implementation) Need to be evaluated based upon
assumptions and validated against experience
Slide 14
Looking at 1918 to see what worked
Slide 15
Weekly mortality data provided by Marc Lipsitch (personal
communication)
Slide 16
Slide 17
Slide 18
Not just what was done but when it was done can make a
difference
Slide 19
Factors Affecting Ability of Communities to Implement Community
Measures Maintenance of critical infrastructure Extent of social
cohesion, organization and trust Government stability, political
will Communication with remote areas Higher population densities in
cities Financial support, compensation Individuals, businesses,
governments
Slide 20
Macroeconomic Analysis Preliminary macroeconomic analyses of
the impact of community-wide interventions have been done, using
several economic models These models predict supply-side impacts
that range from a decrease in overall economic impact as a result
of community-wide interventions, to a modest increase in impact
These estimates do not incorporate the costs associated with lives
lost during a severe pandemic If an economic value is assigned to
lives lost during a severe pandemic, community-wide interventions
result in a 5-10 fold decrease in overall cost
Slide 21
Recent Analyses Suggest That Community Actions May
Significantly Reduce Illness and Death Before Vaccine is Available
Early and uniform implementation of: School closure Keeping kids
and teens at home Social distancing at work and in the community
Encouraging voluntary home isolation by ill individuals and
voluntary home quarantine by the household contacts Treating the
ill and providing targeted antiviral prophylaxis to household
contacts (if available) Implementing measures early and in a
coordinated way
Slide 22
Can history tell us if community interventions work or dont
work?
Slide 23
Why does closing schools make such a difference?
Slide 24
Evidence to Support School Closure Children are more
susceptible to flu and more contagious than adults Children are
believed to be the main introducers of influenza into households.
School closure during influenza epidemics has resulted in
significant decreases in the diagnoses of respiratory infections,
visits to physicians, and emergency departments. Reducing infection
in children (via vaccines) has reduced flu rates in all ages in
community
Slide 25
Children are in close contact at school
Slide 26
Slide 27
Slide 28
Adverse impacts of closing schools
Slide 29
66 million 18 million 9 million8 million 5 million Labor Status
of Parents Source: U.S. Census Bureau, Population Division, Current
Population Survey, 2003 Annual Social and Economic Supplement
http://www.census.gov/population/www/socdemo/hh-fam/cps2003.html
Slide 30
Summarizing.
Slide 31
Community Mitigation Summary Ill persons should be isolated
(home vs hospital) Voluntary home quarantine for household contacts
Social distancing measures School closures may have profound impact
Workplace social distancing and liberal leave NOT closure (for
most) Cancellation of public events Individual infection control
measures Hand washing and cough etiquette for all Mask use for ill
persons, PPE stratified by risk Disinfection of environmental
surfaces as needed
Slide 32
Additional Considerations Planning for adverse impacts of
actions Duration of implementation Intervention fatigue
Socioeconomic disparities Sustained, predictable absenteeism
Economic impact
Slide 33
What Can Be Done Now? Education of leadership in State and
local government about the need for cross-sectoral planning
Engagement of non-health communities: education, private sector,
labor, NGOs Examination of relevant authorities, and scenario-based
discussions of implementation with leaders & public. [Seen
handout on 13 recommendations]
Slide 34
It is better to have approximate answers to the right question
than to have the exact answer to the wrong one. Irene Eckstrand,
NIH