CDC Meeting on Community Mitigation of Pandemic Influenza

1. 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

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?

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.

4. 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 Some Possible Actions

5. #1 Pandemic outbreak: No intervention #2 Daily Cases Pandemic outbreak: With intervention #3 Days since First Case Purpose of Community-Based Interventions 1. Delay outbreak peak 2. Decrease peak burden on hospitals/ infrastructure 3. Diminish overall cases and health impacts

6. Of these options, what will we do and when?

7. Researchers taking two approaches to study effectiveness • Modeling influenza outbreak using mathematical tools • Looking back at data from 1918 to look for evidence that certain interventions worked.

8. Different actions may be taken in a severe pandemic compared to a milder one

9. Mild Moderate Severe Case Fatality Rate ≤ 0.1% 0.1 - 0.5% ≥ 0.5% Isolation Yes Yes Yes Treatment Yes Yes Yes Quarantine No ??? Yes Prophylaxis High-risk individuals High-risk individuals Yes School Closure Reactive Punctuated Proactive Protective sequestration High-risk individuals High-risk individuals Children Community social distancing High-risk individuals Encouraged Encouraged + selective closures Workplace protections Encourage good hygiene Social distancing Aggressive social distancing Liberal leave policies Confirmed influenza Influenza-like illness ILI and/or sick family members Epidemiology Drives Approach SAMPLE

10. What some models tell usabout actions to reducepandemic flu spread

11. Value of combining strategies – Longini model

12. Value of combining strategies – Glass model

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

14. Looking at 1918 to see what worked

15. Weekly mortality data provided by Marc Lipsitch (personal communication)

18. Not just what was done but when it was done can make a difference

19. Factors Affecting Ability of Communities to ImplementCommunity 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

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

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

22. Can history tell us if community interventions work or don’t work?

23. Why does closing schools make such a difference?

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

25. Children are in close contact at school

28. Adverse impacts of closing schools

29. Labor Status of Parents 66 million 18 million 5 million 8 million 9 million 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

30. Summarizing….

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

32. Additional Considerations • Planning for adverse impacts of actions • Duration of implementation • Intervention fatigue • Socioeconomic disparities • Sustained, predictable absenteeism • Economic impact

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, NGO’s • Examination of relevant authorities, and scenario-based discussions of implementation with leaders & public. • [Seen handout on 13 recommendations]

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