schwartz by xiaopangnv

VIEWS: 6 PAGES: 34

									               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

                                                              1   Delay outbreak peak

                                                                  Decompress peak burden on
               Pandemic Outbreak:                             2   hospitals/infrastructure
                 No Intervention
                                                              3   Diminish overall cases
Daily Cases




                                                                  and health impacts




                 Pandemic Outbreak:
                  With Intervention




                                      Days Since First Case
     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.
        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
Markel, JAMA 2008interventions
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     Late (>7 d)   P-value
                              d)
 Time to peak                   18 d        11 d       <0.001
 Magnitude of peak               67.6      125.8       <0.001
 (weekly EDR)
 Excess P & I mortality        451.2       580.3       <0.001
 (total EDR)
 Total days of NPIs
 Outcome                       Longer     Shorter      P-value
                               (>65 d)    (<65 d)
 Excess P & I mortality        451.2       559.3       <0.001
 (total EDR)
Markel, JAMA 2007
                         Public Health Response Time by
                                  Time to Peak
                         35

                         30
   Time to peak (days)




                         25

                         20

                         15

                         10

                          5

                          0
                              -15   -10   -5     0      5         10    15      20   25   30   35
                                               Public health response time (days)

                                           Spearman’s r = -0.74    p < 0.0001

Markel, JAMA 2007
                                      Public Health Response Time by
                                              Mortality Burden
                                      800
  Mortality burden (cumulative EDR)




                                      700

                                      600

                                      500

                                      400

                                      300

                                      200
                                            -15   -10   -5     0      5        10    15      20   25   30   35
                                                             Public health response time (days)

                                                         Spearman’s r = 0.37    p = 0.0080

Markel, JAMA 2007
                                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
 Figure 1


                                     300
                                                                Philadelphia
   Death Rate / 100,000 Population




                                                                St. Louis
                                     250


                                     200


                                     150

                                     100


                                      50


                                       0


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                                       5-




                                       9-
                                     14




                                           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
 Figure 1


                                      300
                                                                        Philadelphia
    Death Rate / 100,000 Population




                                                                        St. Louis
                                      250
                                            Timing
                                      200   of NPIs
                                      150

                                      100

                                                *
                                       50


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                                         -D
                                         -S
                                         -S



                                         -S
                                        5-




                                        9-
                                      14




                                                      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                               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%
     Blendon, Emerg Inf Dis 2008
         U.S. Pandemic Severity Index




     1918




1957, 1968
      Community Mitigation by PSI
                                      Pandemic Severity Index
Interventions by Setting
                                         1           2 and 3      4 and 5

Home
                                    Recommend       Recommend   Recommend
Voluntary isolation


Voluntary quarantine
                                    Generally not
                                                     Consider   Recommend
                                    recommend


School
Dismissal of students from
                                    Generally not   Consider:   Recommend:
schools and closure of child care   recommend       ≤ 4 weeks    ≤ 12 weeks
programs

Reduce out-of-school contacts       Generally not   Consider:   Recommend:
and community mixing                recommend       ≤ 4 weeks    ≤ 12 weeks
        Community Mitigation by PSI
                                               Pandemic Severity Index
  Interventions by Setting
                                                1          2 and 3    4 and 5
Workplace/Community
Adult social distancing

Decrease number of social contacts
                                           Generally not
(e.g., encourage teleconferences,                          Consider   Recommend
                                           recommend
alternatives to face-to-face meetings)

Increase distance between persons
                                           Generally not
(e.g., reduce density in public transit,                   Consider   Recommend
                                           recommend
workplace)
Modify, postpone, or cancel selected
public gatherings to promote social        Generally not
                                                           Consider   Recommend
distance (e.g., stadium events,            recommend
theater performances)
Modify workplace schedules and
practices (e.g., telework, staggered       Generally not
                                                           Consider   Recommend
                                           recommend
shifts)
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
                                                     45%
   households



         Black                             34%




      Disabled                            33%




 Chronically ill                         32%
Blendon, Emerg Inf Dis 2008
            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%


            24%                    25%
                                               22%
                                                         15%




            Total        <$25K   $25-49.9K   $50-74.9K   $75K+


Blendon, Emerg Inf Dis 2008
    Planning to Address Needs of At-risk
                 Populations
•   Guidance for health depts. and
    community-based organizations
     •   Identifying at risk populations
     •   Collaboration and engagement in
         planning 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
    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…

        Family                             50%



       Friends        11%


       Outside
                                  34%
      agencies
                                               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
                                                           Only                    Only                    Only
   no non-                        Children
                                                           Children                Children                Children
   working                            <18
                                                             <15                     <14                     <13
   adults
   (millions)
 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%

 Age Threshold                         18                     15                      14                      13

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
         • 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
 Johnson, Emerg Inf Dis 2008   the decision to close schools
    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

								
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