WWUBroad View

Pandemic InfluenzaFall 2006

Appreciation

• Materials in this program were modified from March 2006 information from the City of Bellingham, courtesy of Fire Chief Bill Boyd

• Some materials were excerpted from a June 23, 2006 National Safety Council presentation by the Centers for Disease Control

Information Provided• Influenza characteristics, symptoms and

transmission• Pandemic influenza characteristics and

current status• Impacts and historical evidence from

previous pandemics• Control and prevention for individuals,

households and at WWU• How WWU is preparing

Influenza

• Contagious disease caused by RNA virus

• Primarily affects the respiratory tract

• Can cause severe illness and lead to life-threatening complications

• Global infectious disease threat

• Annual public health problem

Transmission: How Influenza Spreads

• Contact with respiratory secretions from an infected person via– Coughing or Sneezing– Touching respiratory droplets on:– Self, another person or object

**** THEN *****

• Touching one’s mucous membranes– Eyes, mouth, nose

– Without washing hands

Seasonal Influenza Information

• Incubation period: 1 to 5 days from exposure to onset of symptoms

• Communicability: Maximum 1-2 days before to 4-5 days after onset of symptoms

• Timing: Peak usually occurs December through March in North America

Influenza Symptoms

Rapid onset of:– Fever– Chills– Body aches– Sore throat– Non-productive cough– Runny nose– Headache

Average Influenza Impact in U.S.

• Over 200,000 hospitalizations per year

• About 36,000 deaths per year

• Substantial economic impact– Lost work and school days– Estimated $37.5 billion in costs

(CDC information from National Safety Council)

Seasonal Influenza is a Serious Illness

Who is at greatest risk for serious complications?– Persons 65 and older– Persons with chronic diseases– Infants– Pregnant women– Nursing home residents

Comparison of Pandemic and Seasonal Influenza

• Seasonal caused by subtypes of influenza viruses to which people have been previously exposed

• Pandemics caused by subtypes to which– People have never been previously exposed

OR

– People have not been exposed for a very long time

Defining Pandemic Influenza

Global outbreak with:

– Novel virus - all or most people susceptible

– Readily transmissible from person to person

– Wide geographic spread

Influenza Viruses

• Subtype based on surface glyco-proteins– 16 different hemaglutinins (H)– 9 different neuraminidases (N)

• Human types: H1N1, H3N2• Current avian: H5N1

• RNA viruses mutate very vigorously

Impact of Past Influenza Pandemics

Pandemic Excess Mortality

Populations Affected

1918-19(A/H1N1)

500,000 Persons <65 years

1957-58(A/H2N2)

70,000 Infants, elderly

1968-69(A/H3N2)

36,000 Infants, elderly

1977-78(A/H1N1)

8,300 Young (persons <20)

Severe vs ModerateModerate

1957-like

Severe

1918-like

Illness 90 million (30%) 90 million (30%)

Outpatient medical care

45 million (50%) 45 million (50%)

Hospitalization 865,000 (1%) 9,900,000 (11%)

ICU Care 128,750 (0.1%) 1,485,000 (1.7%)

Mechanical Ventilation

64,875 (0.07%) 745,500 (0.8%)

Deaths 209,000 (0.2%) 1,903,000 (2.1%)

Pandemic Influenza: 2nd waves

• 1957: second wave began 3 months after peak of the first wave

• 1968: second wave began 12 months after peak of the first wave

Close Calls: Avian Influenza Transmitted to Humans

1997: H5N1 in Hong Kong 18 hospitalizations and 6 deaths

1999: H9N2 in Hong Kong 2 hospitalizations

2003: H5N1 in China 2 hospitalizations, 1 death

H7N7 in the Netherlands 80 cases, 1 death (eye infections, some respiratory symptoms)

Avian Influenza Poultry Outbreaks, Asia, 2003-04

Human Cases as of March 2006

H5N1 Poultry Influenza Current Outbreaks (as of Feb 2006)

• Africa: Niger Nigeria • East Asia & the Pacific: Cambodia, China, Hong Kong,

(SARPRC), Indonesia, Japan, Laos, Malaysia, Mongolia, Thailand, Vietnam

• Europe & Eurasia: Austria, Azerbaijan, Bosnia & Herzegovina (H5), Bulgaria ,Croatia, France, Germany, Greece, Italy, Romania, Russia, Slovak Republic, Slovenia, Switzerland (H5), Turkey, Ukraine

• Near East: Egypt, Iraq, (H5) Iran • South Asia: India

Location of Human cases – H5N1

• East Asia and the Pacific: – Cambodia – China – Indonesia – Thailand – Vietnam

• Europe & Eurasia: – Turkey

• Near East: – Iraq

Avian Influenza High Concerns

• Has caused severe disease in humans who have been infected

• Limited human-human transmission has occurred in Asia

• Could evolve to be readily transmissible between humans

• No vaccine for humans is available• Limited supply of expensive antiviral

medicines

“The pandemic clock is ticking, we just don’t know what time it is”

E. Marcuse

Historical Review of Pandemic

• 1918-19 is selected because– Severity of disease– Enormous impact on society

The 1918 Influenza Pandemic

America’s Forgotten Pandemicby Alfred Crosby

“The social and medical importance of the 1918-1919 influenza pandemic cannot be overemphasized.

It is generally believed that about half of the 2 billion people living on earth in 1918 became infected. At least 20 million people died.

In the Unites states, 20 million flu cases were counted and about half a million people died. It is impossible to imagine the social misery and dislocation implicit in these dry statistics.”

America’s deaths from influenza were greater than the number of U.S. servicemen

killed in any war

0

100

200

300

400

500

600

700

800

900

Civil WWI 1918-19 WWII Korean Vietnam

War Influenza War War

Thousands

Influenza Control Measures

• Vaccines

• Anti-viral medicines

• Preventing transmission – Infection control

• Preventing contact – Social distancing

Preventing TransmissionInfection Control

• Hand hygiene

• Face masks for symptomatic persons

• Isolation of ill people and quarantine of those exposed

Preventing Contact Social Distancing

• School closures

• Cancellation of public gatherings

• Deferring travel to involved areas

• Providing alternatives to face-to-face contacts at work and in other venues

• Increasing distances between people over 3 feet

• Decreasing contact between people

Influenza Control: Quarantine

• Challenges– short incubation period for influenza– a large proportion of infections are

asymptomatic– clinical illness from influenza infection is non

specific

• Not used during annual epidemics

• Could potentially slow onset of a pandemic before sustained person-to-person transmission has been established

Medical Care during an Influenza Pandemic

• Surge capacity of the hospital system is limited

• Challenges:– Magnitude and duration– Staff shortages– Limited ability to call in external resources

U.S. HHS Doctrine: Save Lives

U.S. Health & Human Services Department:

• Slow spread, decrease illness and death, buy time

• Lowers the peak burden on medical infrastructure

• Diminishes overall cases & impacts

No Intervention

Intervention

Despite . . . – Expanded global and national surveillance – Better healthcare, medicines, diagnostics– Greater vaccine manufacturing capacity

New risks:– Increased global travel and commerce– Greater population density– More elderly and immunosuppressed– More daycare and nursing homes

Pandemic Flu Today

On-line resources

• www.pandemicflu.gov

• www.cdc.gov/business

• www.doh.wa.gov/panflu/

• www.dhhs.gov/nvpo/pandemics/

• www.wwu.edu/depts/ehs/pandemic.shtml

How WWU is Preparing

• Pandemic Policy approved

• Pandemic response plan being developed

• Web page available

• Exercise conducted August 2006