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Transcript of Non-pharmaceutical Interventions for an Influenza Pandemic: U.S. Approach to Community Mitigation...
Non-pharmaceutical Interventions for an Influenza Pandemic:
U.S. Approach to Community Mitigation and Prevention of
Secondary Effects
Benjamin Schwartz, MDNational Vaccine Program Office
U.S. Department of Health and Human Services
September 2008
Presentation Outline
U.S. non-pharmaceutical intervention (NPI) strategy and rationale
– Hygiene and respiratory protection interventions not included in this presentation
Potential secondary (adverse) consequences of NPI strategies and approaches to mitigation
Applicability of NPIs globally
Days Since First Case
Dai
ly C
ases
Goals of Community Mitigation
Pandemic Outbreak:No Intervention
Pandemic Outbreak:With Intervention
Delay outbreak peak
Decompress peak burden on hospitals/infrastructure
Diminish overall cases and health impacts
2
1
3
Scientific Basis for NPI Strategy
• Person-to-person transmission of influenza
• Primary role for respiratory droplets
• Epidemiological data support need for close contact
• Transmission may occur before symptoms
• Pandemic and seasonal influenza data on role of children in spreading infection in communities
• Mathematical modeling results on the impacts of single and combined interventions
• Historical analysis of interventions in U.S. cities during the 1918 pandemic
Historical Analysis of NPIs During the 1918-19
Pandemic• Objective – determine whether city to city
variation in mortality was related to timing, duration, or combination of NPIs
• Data and analysis• Mortality data from 43 urban areas, Sept 1918 –
Feb 1919
• Information on interventions from public health, newspapers, and other sources (n = 1143)
• NPIs considered included gathering bans, closing schools, and mandatory isolation and quarantine
• Excess death rate analyzed as a function of type and timing of interventionsMarkel, JAMA 2008
Markel et al. JAMA 2007
NPIs Implemented in U.S. Cities, 1918-19
Associations of NPIs and Excess P & I Mortality, 1918-
19
Markel, JAMA 2007
Public health response time
Outcome Early (<7 d)
Late (>7 d)
P-value
Time to peak 18 d 11 d <0.001
Magnitude of peak (weekly EDR)
67.6 125.8 <0.001
Excess P & I mortality (total EDR)
451.2 580.3 <0.001
Total days of NPIs
Outcome Longer (>65 d)
Shorter (<65 d)
P-value
Excess P & I mortality (total EDR)
451.2 559.3 <0.001
0
5
10
15
20
25
30
35
-15 -10 -5 0 5 10 15 20 25 30 35
Public health response time (days)
Tim
e t
o p
ea
k (d
ays
)
Public Health Response Time by Time to Peak
Spearman’s r = -0.74 p < 0.0001
Markel, JAMA 2007
200
300
400
500
600
700
800
-15 -10 -5 0 5 10 15 20 25 30 35
Public health response time (days)
Mo
rta
lity
bu
rde
n (
cum
ula
tive
ED
R)
Public Health Response Time by Mortality Burden
Spearman’s r = 0.37 p = 0.0080
Markel, JAMA 2007
City First Cases Death Rate
Boston 8/27/18 5.7
Philadelphia By 9/11/18 7.4
New Haven Week of 9/11/18 5.1
Chicago 9/11/18 3.5
New York Before 9/15/18 4.1
Pittsburgh Mid-9/18 6.3
Baltimore 9/17/18 6.4
San Francisco 9/24/18 4.7
Los Angeles “Last days 9/18” 3.3
Milwaukee 9/26/18 1.8
Minneapolis 9/27/18 1.8
St. Louis Before 10/3/18 2.2
Toledo “First week 10/18” 2.0
1918 Outcomes by City
Death rate from influenza and pneumonia / 1000 population: "Causes of Geographical Variation in the Influenza Epidemic of 1918 in the Cities of the United States," Bulletin of the National Research Council, July, 1923, p.29.
0
50
100
150
200
250
300
Date
De
ath
Ra
te /
10
0,0
00
Po
pu
lati
on
PhiladelphiaSt. Louis
Figure 1
Excess P&I Mortality in Philadelphia and St. Louis, 1918
Source: Hatchett, Mecher, & Lipsitch. Public health interventions and epidemic intensity during the 1918 influenza pandemic. PNAS Early Edition. April 6, 2007
0
50
100
150
200
250
300
Date
De
ath
Ra
te /
10
0,0
00
Po
pu
lati
on
PhiladelphiaSt. Louis
Figure 1
Source: Hatchett, Mecher, & Lipsitch. Public health interventions and epidemic intensity during the 1918 influenza pandemic. PNAS Early Edition. April 6, 2007
*
* Estimate based on back extrapolation of death to incidence curves
Excess P&I Mortality in Philadelphia and St. Louis, 1918
Timingof NPIs
U.S. Community Mitigation Interventions
• Asking sick people to stay home (voluntary isolation)
• Asking household members of a sickperson to stay home (voluntary quarantine)
• Dismissing children from schools and closing childcare and keeping kids and teens from re-congregating and mixingin the community
• Social distancing at work and in the community
Implementing measures in a uniform way as early as possible during community
outbreaksCDC. Interim pre-pandemic planning guidance: community strategy for pandemic influenza mitigation in the United States. 2007 Feb http://www.pandemicflu.gov/plan/community/commitigation.html
Layered Solutions
Potential Secondary Effects of Community Mitigation
Isolation & quarantine
– Income & job security
– Ability to access support and essential services
Dismissal of children from school & closing childcare
– Child minding responsibilities and absenteeism
– Educational continuity
– School breakfast and lunch programs
Social distancing at work and in communities
– Business continuity and sustaining essential services
Public & Stakeholder Engagement on Community Mitigation
Acceptability of interventions assessed in public and stakeholder meetings
Concern expressed on the ability to apply and effectiveness of interventions
In a severe pandemic, where a high mortality rate is anticipated, participants were willing to “risk” undertaking interventions of unclear effectiveness to mitigate disease & death
Planners should work to reduce secondary adverse effects of intervention
Willingness to Follow Recommendations
Stay at home for 7 -10 days if sick 94%
All members of HH stay at home for 85% 7 -10 days if one member of HH sick
Could arrange care for children if 93% schools/daycare closed 1 month
Could arrange care for children if 86% schools/daycare closed 3 months
Keep children from gathering outside 85% home while schools closed for 3 months
Would avoid mass gatherings for 1 month 79 – 93%
Poll results from representative national sample of 1,697 adults
conducted in September-October, 2006
Blendon, Emerg Inf Dis 2008
U.S. Pandemic Severity Index
1957, 1968
1918
Community Mitigation by PSI
Interventions by Setting
Pandemic Severity Index1 2 and 3 4 and 5
Home
Voluntary isolation
Recommend Recommend Recommend
Voluntary quarantine Generally not recommend
Consider Recommend
SchoolDismissal of students from schools and closure of child care programs
Generally not recommend
Consider:≤ 4 weeks
Recommend:≤ 12 weeks
Reduce out-of-school contacts and community mixing
Generally not recommend
Consider:≤ 4 weeks
Recommend:≤ 12 weeks
Interventions by SettingPandemic Severity Index
1 2 and 3 4 and 5
Workplace/CommunityAdult social distancing
Decrease number of social contacts (e.g., encourage teleconferences, alternatives to face-to-face meetings)
Generally not recommend
Consider Recommend
Increase distance between persons (e.g., reduce density in public transit, workplace)
Generally not recommend
Consider Recommend
Modify, postpone, or cancel selected public gatherings to promote social distance (e.g., stadium events, theater performances)
Generally not recommend
Consider Recommend
Modify workplace schedules and practices (e.g., telework, staggered shifts)
Generally not recommend
Consider Recommend
Community Mitigation by PSI
CDC’s Proposed Pandemic Intervals
Caregiving for Ill Persons
32%
33%
34%
45%
24%
Chronically ill
Disabled
Black
One-adulthouseholds
Total
% saying they have no one to take care of them at home if they were sick for 7-10 days
Blendon, Emerg Inf Dis 2008
24%
36%
25%22%
15%
Total <$25K $25-49.9K $50-74.9K $75K+
% saying they have no one to take care of them at home if they were sick for 7-10 days
Caregiving for Ill Persons
Blendon, Emerg Inf Dis 2008
Planning to Address Needs of At-risk Populations
• Guidance for health depts. andcommunity-based organizations
• Identifying at risk populations
• Collaboration and engagement inplanning for a pandemic
• Communications and education
• Existing activities and best practices – links to materials
• Recommendations for planning
• Guidance on vaccine prioritization targets community support service providers
Examples of Community Planning
• New Jersey
• Special Needs Advisory Panel – representatives of 30 organizations – advises the Office of Emergency Management
• Identifies critical issues affecting at risk populations
•Educates emergency management personnel
•Makes recommendations for planning and liaison with community groups
•Drafts proposed legislation
• Mississippi – 4 rural counties
• Developed operations plan creating neighborhood networks
• Local fire departments and churches monitor neighborhoods to identify and assist at risk populationshttp://www.astho.org/pubs/ASTHO_ARPP_Guidance_June3008.pdf
35% 64%
85%
34%
11%
50%
If recommended by health officials, could keep children from going to public events and gathering outside home while schools closed for 3 months
Would need help with problems of having children at home
Family
Among those who would need a lot or some help, would rely most on…
Friends
Outside agencies
A lot/some Only a little/None
Dismissing Children from Schools:
Child Minding Needs
Blendon, Emerg Inf Dis 2008
U.S. Household Survey Data, 2006
Source: Department of Labor, Office of the Assistant Secretary for Policy calculations from Current Population Survey microdata.
31 million
45 million
33 million
7 million
Households with children and no non-working adults (millions)
Children <18
Only Children
<15
Only Children
<14
Only Children
<13
Single adult in HH 5.1 3.5 3.2 2.8
Two adults 14.3 10.6 9.6 8.7
Multiple adults 2.5 1.3 1.1 0.9
Total 22.0 15.4 13.8 12.4
%Absenteeism 16% 11% 10% 9%
Source: Department of Labor, Office of the Assistant Secretary for Policy calculations from Current Population Survey microdata.
Absenteeism Related to Child Minding:
Impact of Age Threshold
Age Threshold 18 15 14 13
Household Response to School Closure during a Seasonal Influenza Outbreak
• Influenza B outbreak in Yancey County, NC
• Schools closed. Nov 2 to 12
• Parents surveyed on child minding and absenteeism
• Results• In 54% of households, all adults worked
•18% had occupations allowing them to work from home
• 24% of adults missed >1 day of work; of these only 18% missed work because of school closure
•76% of parents had existing childcare arrangements
•10% made arrangements with family or friends
• 91% agreed with the decision to close schoolsJohnson, Emerg Inf Dis 2008
Business Planning to Maintain Essential Services and Support
Employees• Reduce absenteeism
• Implement measures toprotect workers
• Support planning forchild minding
• Plan to maintainessential functions• Teleworking, cross-training for essential functions
• Support employee families• Modify leave policies for a pandemic & other
emergencies
Global Issues in Implementation of NPIs
• Community strategies may be especially important in settings where vaccine and antiviral drugs are not initially available
• Evidence base for community measures in developing countries is limited• Strategies are based on influenza transmission
• Relative importance of different measures may differ from industrialized countries
• Secondary (adverse) impacts also may differ
• Ethical and societal considerations • Balance pandemic response with rights and values
• Recognize other threats to health
Community Mitigation Strategies: International Pandemic Planning
Issues Socio-cultural attitudes (individualism vs. community)
Health care delivery systems
Socio-economic structure and workforce
Housing structure and density
Urban vs. rural populations
Access to sustainable nutrition and clean water
Sanitation and hygiene
Educational infrastructure
Legal authorities, enforcement & ethical construct
Political / Governmental framework
• Focus on business continuity, worker protection, and family/ community preparedness
• Planning materials and strategies for business outreach being developed
Asia Pacific Economic Cooperation (APEC) Business Planning
Conclusions: Planning and Implementing Community Mitigation
Proposed strategies based on current science
Early implementation of multiple interventions most effective
Duration of implementation important
Match intervention with pandemic severity
Planning requires action of government, private sector, and communities
Plan for second-order effects
Consider at-risk populations