Transcript Slide 1

September 2008
Non-pharmaceutical Interventions
for an Influenza Pandemic:
U.S. Approach to Community
Mitigation and Prevention of
Secondary Effects
Benjamin Schwartz, MD
National Vaccine Program Office
U.S. Department of Health and Human Services
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
Goals of Community Mitigation
Daily Cases
Pandemic Outbreak:
No Intervention
Pandemic Outbreak:
With Intervention
Days Since First Case
1
Delay outbreak peak
2
Decompress peak burden on
hospitals/infrastructure
3
Diminish overall cases
and health impacts
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 interventions
Markel, JAMA 2008
NPIs Implemented in U.S. Cities, 1918-19
Markel et al. JAMA 2007
Associations of NPIs and Excess
P & I Mortality, 1918-19
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
451.2
580.3
<0.001
Longer
(>65 d)
Shorter
(<65 d)
P-value
451.2
559.3
<0.001
Excess P & I mortality
(total EDR)
Total days of NPIs
Outcome
Excess P & I mortality
(total EDR)
Markel, JAMA 2007
Public Health Response Time by
Time to Peak
35
Time to peak (days)
30
25
20
15
10
5
0
-15
-10
-5
0
5
10
15
20
Public health response time (days)
Spearman’s r = -0.74
Markel, JAMA 2007
p < 0.0001
25
30
35
Mortality burden (cumulative EDR)
Public Health Response Time by
Mortality Burden
800
700
600
500
400
300
200
-15
-10
-5
0
5
10
15
20
Public health response time (days)
Spearman’s r = 0.37
Markel, JAMA 2007
p = 0.0080
25
30
35
1918 Outcomes by City
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
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.
Excess P&I Mortality in Philadelphia
and St. Louis, 1918
Death Rate / 100,000 Population
Figure 1
300
Philadelphia
St. Louis
250
200
150
100
50
0
t
t
t
t
ep Sep Sep Oc Oc Oc Oc Nov N ov Nov Nov N ov D ec D ec Dec Dec
S
5 12 19 26
2- 9- 16- 23- 30- 7- 14- 21- 2814 21 28
Date
Source: Hatchett, Mecher, & Lipsitch. Public health interventions and epidemic
intensity during the 1918 influenza pandemic. PNAS Early Edition. April 6, 2007
Excess P&I Mortality in Philadelphia
and St. Louis, 1918
Death Rate / 100,000 Population
Figure 1
300
Philadelphia
St. Louis
250
200
Timing
of NPIs
150
100
50
*
0
t
t
t
t
ep Sep Sep Oc Oc Oc Oc Nov N ov Nov Nov N ov D ec D ec Dec Dec
S
5 12 19 26
2- 9- 16- 23- 30- 7- 14- 21- 2814 21 28
Date
* Estimate based on back extrapolation of death to incidence curves
Source: Hatchett, Mecher, & Lipsitch. Public health interventions and epidemic
intensity during the 1918 influenza pandemic. PNAS Early Edition. April 6, 2007
U.S. Community Mitigation Interventions
•
Asking sick people to stay home
(voluntary isolation)
•
Asking household members of a sick
person to stay home (voluntary quarantine)
•
Dismissing children from schools and
closing childcare and keeping kids and
teens from re-congregating and mixing
in the community
•
Social distancing at work and in the community
Implementing measures in a uniform way as early as
possible during community outbreaks
CDC. 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
Poll results from representative national sample of 1,697 adults
conducted in September-October, 2006

Stay at home for 7 -10 days if sick
94%

All members of HH stay at home for
7 -10 days if one member of HH sick
85%

Could arrange care for children if
schools/daycare closed 1 month
93%

Could arrange care for children if
schools/daycare closed 3 months
86%

Keep children from gathering outside
home while schools closed for 3 months
85%

Would avoid mass gatherings for 1 month
79 – 93%
Blendon, Emerg Inf Dis 2008
U.S. Pandemic Severity Index
1918
1957, 1968
Community Mitigation by PSI
Interventions by Setting
Pandemic Severity Index
1
2 and 3
4 and 5
Recommend
Recommend
Recommend
Generally not
recommend
Consider
Recommend
Dismissal 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
Home
Voluntary isolation
Voluntary quarantine
School
Community Mitigation by PSI
Interventions by Setting
Pandemic Severity Index
1
2 and 3
4 and 5
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
Workplace/Community
Adult social distancing
CDC’s Proposed Pandemic Intervals
Caregiving for Ill Persons
% saying they have no one to take care of them at home
if they were sick for 7-10 days
Total
24%
One-adult
households
Black
Disabled
Chronically ill
Blendon, Emerg Inf Dis 2008
45%
34%
33%
32%
Caregiving for Ill Persons
% saying they have no one to take care of them at home
if they were sick for 7-10 days
36%
25%
24%
22%
15%
Total
<$25K
Blendon, Emerg Inf Dis 2008
$25-49.9K
$50-74.9K
$75K+
Planning to Address Needs of At-risk
Populations
•
•
Guidance for health depts. and
community-based organizations
•
•
Identifying at risk populations
•
•
Communications and education
•
Recommendations for planning
Collaboration and engagement in
planning for a pandemic
Existing activities and best
practices – links to materials
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 populations
http://www.astho.org/pubs/ASTHO_ARPP_Guidance_June3008.pdf
Dismissing Children from Schools:
Child Minding Needs
If recommended by health officials, could keep children from going to public
events and gathering outside home while schools closed for 3 months
85%
Would need help with problems of having children at home
A lot/some
Only a little/None
35%
64%
Among those who would need a lot or some help, would rely most on…
50%
Family
Friends
Outside
agencies
11%
34%
Blendon, Emerg Inf Dis 2008
U.S. Household Survey Data, 2006
Single adult with no children<18
Two or more adults with no children<18
Single Adult with children<18
Two or more adults with children<18
38.8%
45 million
26.9%
31 million
7 million
33 million
6.1%
28.2%
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
Households with
children and
no nonworking
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%
18
15
14
13
Age Threshold
Source: Department of Labor, Office of the Assistant Secretary for Policy calculations from Current Population Survey microdata.
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
•
•
24% of adults missed >1 day of work; of these only 18%
missed work because of school closure
•
•
•
18% had occupations allowing them to work from home
76% of parents had existing childcare arrangements
10% made arrangements with family or friends
91% agreed with the decision to close schools
Johnson, Emerg Inf Dis 2008
Business Planning to Maintain Essential
Services and Support Employees
•
•
Reduce absenteeism
•
Implement measures to
protect workers
•
Support planning for
child minding
Plan to maintain
essential 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
Asia Pacific Economic Cooperation
(APEC) Business Planning
•
Focus on business continuity,
worker protection, and family/
community preparedness
•
Planning materials and
strategies for business
outreach being developed
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