Update: “New Flu” Activity and Community Mitigation

Diane Woolard, PhD, MPH

Director, Division of Surveillance and Investigation

Virginia Department of Health

Outline

• Update on H5N1 and H1N1 activity– Comparison of the two

• Review of purpose and strategies for community mitigation

• Community mitigation recommendations for the new H1N1 virus situation

Avian Reservoir

Avian virus

Human virus

Pandemic Strain Emergence: Direct Infection vs. Reassortment

other mammals?New

reassorted virus

Direct Infection

Criteria for PandemicH5N1 H1N1 Criterion

√ √ Novel strain that is not recognized by the human immune system

√ X Causes increased sickness and death

X √- Sustained person-to-person transmission

H5N1 vs. H1N1 Characteristics

H5N1 H1N1

Cases 423 4694

Deaths 258 53

Countries 15 30

Case-fatality 61% 1%

Year began 1997, 2003 2009

* As of May 11, 2009

H1N1 in US and VA

US Virginia

Cases 2618 17

Deaths 3 0

Distribution 44 states 6 districts

Case-fatality 0.1% 0%

* As of May 11, 2009

Inter-pandemic phase Low risk of human cases 1

New virus in animals; no human cases

Higher risk of human cases 2

Pandemic alert No or very limited human-to-human transmission 3

Virus causes human cases Evidence of increased human-to-human transmission

4

Evidence of significant human-to-human transmission

5

Pandemic Efficient & sustained human-to-human transmission

6

WHO Pandemic Alert Phases

Community Mitigation

• Goal: Slow disease spread – allows time for vaccine development,

manufacturing, distribution and antiviral distribution

• Barrier: Influenza is hard to control– Short incubation period; non-specific nature of

clinical illness; easy to spread, even before symptoms

Community-Based Interventions

Community Mitigation Strategies(Non-pharmaceutical interventions)

• Infection control and hygiene• Social distancing• Community education• Cluster containment• Data collection and management to guide

decisions

A Layered Approach

Individual / Household

Hand hygieneCough etiquetteInfection controlLiving space controlIsolation of illDesignated care

providerRespiratory protection

Community

Isolation of illTreatment of illQuarantine of exposedProphylaxis of exposedSchool/daycare closureSocial distancing

- Community- Workplace

Liberal leave policiesSnow daysTravel restrictions

International

Containment-at-sourceSupport efforts to

reduce transmissionTravel advisoriesLayered screening of

travelersHealth advisoriesLimited points of entry

Targeted, Layered Containment (TLC) utilizing multiple partially effective interventions

What was recommended?

Infection control and hygieneIsolationPublic educationContainment of clustersSocial distancing – someUse of information to guide decisions

Social Distancing for H1N1

• Quarantine – consider minimizing time in crowds, isolate on first sign of illness

• Airport screening – observe & report ill• School closure – strongly consider to consider

to local decision –– Early identification of ill– Stay home with sick– Cough etiquette, handwashing– Closure at discretion of local authorities

Social Distancing, continued

• College/university – treat as community – isolate, cover cough, no cancelling

• Mass gatherings – – if ill, stay home– if high risk, consider risk, consider avoiding

• Business – telecommuting & snow days – not really emphasized

• [Respiratory protection – mask if ill and in public; respirator if caring for ill]

Use Information to Guide Decisions

• Epidemiology – studying patterns of disease in population– What is illness – case definitions– How much illness is occurring – surveillance;

testing recommendations; assess severity and spread

– What populations are affected – descriptive– What are the risk factors – analytic

• Use this information to develop prevention messages and recommendations

Challenges that Arose

• Definition of community – case definition included travel to affected community

• Data release at district level – citizens wanted to know city/town

• Testing purpose and protocol – public health and clinical management

• Interpretation of recommendations – school/childcare, masks

We’re claiming a success

Questions and Discussion