PUBLIC HEALTH ALWAYS WORKING FOR A SAFER AND HEALTHIER WASHINGTON 2009 (Pandemic) H1N1 Influenza Virus Washington State Department of Health Based on slides

PUBLIC HEALTH ALWAYS WORKING FOR A SAFER ANDHEALTHIER WASHINGTON

2009 (Pandemic) H1N1 Influenza Virus

Washington State Department of HealthBased on slides from:

Anthony A MarfinMarcia Goldoft


Outline

Influenza, the illness

Seasonal vs. pandemic influenza

Current pandemic situation reports

What to expect this fall / winter

Public health response


What Is “Influenza-like Illness” (ILI)?

Virus causing two respiratory disease syndromes

ILI (upper respiratory tract)

Fever plus cough or sore throat

Lots of other symptoms

Severe acute respiratory illness (SARI)

ILI plus SOB, tachypnea, hypoxia

Lower lung involvement

ILI or SARI not only from influenza


You can have a mild case of influenza,You can have a mild case of influenza,but influenza is not a mild illness.but influenza is not a mild illness.


Seasonal Influenza Viruses

Seasonal A H3N2, A H1N1, and B viruses spread by

respiratory secretions

Toddlers, children, and adolescents transmit readily

Most cases in these age groups

Very young/old persons at risk for severe illness

Most deaths in these age groups

Vaccine is the best and most cost-effective control


Each year, seasonal flu accounts for:

36,000 deaths

200,000 hospitalizations

20,000,000 ILIs (may or may not be medically attended)

? Asymptomatic infections


Seasonal vs. Pandemic Influenza

Every year, viruses change a little (“drift”)Seasonal flu epidemics each winterQuickly adjust vaccine annually

Rarely, viruses change a lot (“shift”)Entirely new viruses so nobody immune Spread easily among non-immune humansWorldwide epidemic transmission (pandemic)Develop new vaccine over many months


Pandemic Influenza 1918Estimated 675,000 deaths / 105 million US population (0.6%)

Public health challenges compared to now: war troop transport,

lack of health care, lack of public health planning, interrupted

public services (garbage, mail, telegraph, telephone)

Deaths due to infectious diseases, United States 1900-1994

1918 influenza pandemic

Philadelphia was overwhelmed by the number of dead. Burials were done without coffins, eventually in mass graves dug by steam shovels.


Influenza Deaths, 1918 Compared to 1915

0

200

400

600

800

1000

1200

Spokane Seattle

1915 1918

9


Current Situation Current Situation United States and Washington United States and Washington

Beginning April 2009Beginning April 2009


Avianinfluenza viruses

H1N1 2009 Influenza Virus Pedigree

Eurasian swineA/H1N1

(1979-present)

Human “seasonal”A/H3N2

(1968-present)

North American swineA/H1N1

(1918-present)

“Triple reassortant”Swine A/H1N2(1998-present)

2009 HumanA/H1N1

(2009-??)?

Human seasonalA/H1N1

(1977-present)


2009 H1N1 Influenza

Entirely new virus so nobody immune

First identified in California and Mexico, April 2009

Initial investigations → virus found in many states

Summer 2009, worldwide spread

Globally, most flu cases due to 2009 H1N1

Flu pandemic declared by WHO June 2009

Flu cases in U.S. and Washington continued

through summer into fall (unusual)

Severe cases and deaths


Risk for severe infections with 2009 H1N1

Lung disease (asthma, smoking, COPD)

Diabetes

Pregnant

Heart disease

Other chronic medical conditions

Neuro-developmental disease in children

2009 H1N1 Influenza


Flu virus testing in typical flu season in early 2009 with mix of seasonal H1N1, H3N2, A not typed, and B viruses.


New H1N1 virus in April.


Percentage of ER Visits for ILI by CDC Week, Western Washington 2009

May

October


What Can We Expect This Winter?

More cases of flu than in typical years, particularly

in younger ages

Absenteeism due to own or family illness

More deaths because more cases

More deaths in younger ages because more cases

in younger ages

With seasonal flu, 90+ % deaths are ≥ 65 years

With H1N1 flu, 90+ % death are < 65 years


Public Health Response


Components of Response

Surveillance

Community Mitigation

Healthcare Planning

Communication

Continuity of Operations Planning


Influenza Surveillance in Washington

Asymptomatic

ILI cared for at home

Medically attended ILI

Hospitalized

DiedMandatory reporting in Washington

Sentinel physicians, aggregate lab data, syndromic surveillance

Community survey, school absenteeism


Community MitigationInterventions that lessen the impact of a pandemic

Community mitigation can include:

Non-pharmaceutical interventionsIsolation (ill)Quarantine (exposed to ill)School ClosureCommunity Social DistancingCommunity Infection control

Pharmaceutical InterventionsAntiviralsVaccine


Goals of Community Mitigation

Days Since First Case

Dai

ly C

ases

Pandemic Outbreak:No Intervention

Pandemic Outbreak:With Intervention

Delay outbreak peak

Decompress peak burden on hospitals/infrastructureDiminish overall cases and health impacts

2

1

3


What you can do Wash your hands.

Cover your cough.

Don’t touch your eyes, nose and mouth

Try to avoid contact with sick people.

Make a family plan.

Stay home if you’re sick.

Get vaccinated (flu and maybe pneumococcal).


Current CDC and DOH Community Mitigation Strategy for 2009 H1N1H1N1 not severe enough for widespread community social distancing (e.g., school closures)

Protect overall public health by:

Reducing community transmission

Minimizing severe cases

Preventing social disruption

May change – influenza is unpredictable!

Still need to prepare for a major epidemic like 1918


Antiviral and Vaccine Distribution

DOH received antivirals and N95 masks from the

Strategic National Stockpile (SNS) this spring

DOH receiving H1N1 vaccine this fall as available

DOH distributed antivirals and vaccine to LHJs

Monitoring the usage of antiviral medications

Usage has rapidly

increased over the past

few weeks


ACIP Target Populations for H1N1 Vaccination*

Pregnant women

Household contacts and caregivers for children younger than 6 months of age

Healthcare and emergency medical services personnel

All people from 6 months through 24 years of age

Persons aged 25 through 64 years who have health conditions associated with higher risk of medical complications from influenza

*MMWR 2009;58:1-8


http://www.statesman.com/news/content/news/stories/local/2009/09/22/rbz-Hospital-Flu-Tents-05.html

Dell Children's Medical Center in Austin is seeing hundreds of patients a day with flu-like symptoms and is preparing triage tents to handle the volume.

Hospitals are screening and limiting visitors.


Communication

Complex messages need to be communicated to

the public and healthcare providers

Complex public messages

Disease severity

Seeking medical care

Vaccine safety

Complex healthcare provider messages

Purpose of the Public Health Laboratories

Treatment recommendations


COOP

Identify who will be affectedPlan for workforce reduction and support of workersCross-training for critical jobsConsider flexible work schedulesReduce spread of influenza

Promote cough etiquette and hand cleaningPromote vaccination (flu and pneumococcal)Provide routine environmental cleaningEncourage use of sick leave for self-isolation at home


More information

Washington State Department of Health

http://www.doh.wa.gov/H1N1/

Local public health departments

http://www.doh.wa.gov/LHJMap/

Federal government

http://www.flu.gov/


Thank you. Questions?

Documents

PUBLIC HEALTH ALWAYS WORKING FOR A SAFER AND HEALTHIER WASHINGTON 2009 (Pandemic) H1N1 Influenza Virus Washington State Department of Health Based on slides