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