Chicago Department of Public Health Local and Global Public Health Links: Preparation for an Influenza Pandemic Nicole J. Cohen, MD, MSc Chicago Department

Chicago Department of Public

Health

Local and Global Public Health Links: Preparation for an Influenza Pandemic

Nicole J. Cohen, MD, MScChicago Department of Public Health

The University of Chicago’s Summer Institute for Educators

June 29, 2006

Chicago Department of Public Health

Influenza Virus Three types of influenza

virus: A, B, C Only influenza A and B

viruses cause significant disease and epidemics in humans


Influenza A Viruses Classified into subtypes based on

two surface proteins, hemagglutinin (HA) and neuraminidase (NA)

16 HAs and 9 NAs in total Currently in humans:

H1N1 H3N2


Influenza A Susceptible Hosts


Influenza B Viruses No subtypes Infect humans almost exclusively



Avian Influenza Infection of bird with influenza A virus Different strains from the ones that cause human

infections annually Occurs naturally High vs low pathogenicity viruses Highly contagious among bird populations Usually spread from wild birds to domestic poultry May be carried by birds without causing disease May cause severe illness and/or death among

birds Rarely infects humans


Symptoms of Avian Influenza in Humans

Wide range of symptoms depending on type of virus

Typical flu symptoms (fever, cough, sore throat, muscle aches)

Conjunctivitis (eye infection) Viral pneumonia Severe respiratory illness May be life threatening


H5N1 Influenza Virus 1996 First identified in a goose in

China 1997 First human cases in Hong Kong

18 confirmed cases, 6 deaths 150 million chickens slaughtered to

control outbreak 2/2003 Two cases in a Hong Kong

family who traveled to mainland China




Current Situation Human Cases -- June 20, 2006

Azerbaijan Cambodia China Djibouti Egypt

Indonesia Iraq Thailand Turkey Viet Nam

228 Cases

130 deaths

Death rate approximately 50%




How avian influenza infects people

Virus present in respiratory secretions and feces of infected birds

Human infection has resulted from Close contact with infected birds Contact with or consumption of raw poultry

products Contact with contaminated surfaces (feces)

Generally has not spread from person to person Has been suggested in several small family clusters

after extremely close contact with sick person Has not spread beyond one person Has not spread to health care workers



How human influenza spreads

Respiratory droplets Coughing, sneezing Spreads through close contact (less than 3 feet) Prevent by “covering cough”, wearing masks in

medical situations Hand contamination then touching eyes, nose, or

mouth Direct contact e.g. shaking hands with infected person Contact with objects contaminated by influenza viruses

(e.g. doorknobs, phones) Prevent by hand hygiene, gloves in medical situations


H5N1: Is there a vaccine? A vaccine against H5N1 is under

development Not commercially available Annual influenza vaccine does not

protect against H5N1


H5N1: Is treatment available?

Most H5N1 viruses are resistant to older class of antivirals (amantadine and rimantadine)

May be treated with newer antivirals Tamiflu® or Relenza®

Effectiveness is not known Some resistance to Tamiflu® has been

identified


Advice for Travelers CDC has not recommended that the general

public avoid travel to any of the countries affected by avian influenza

Receive routine flu vaccine (if available) prior to departure

If traveling to any country with a known outbreak of H5N1 influenza Avoid poultry farms Avoid contact with animals in live food markets Avoid contact with any surfaces that appear to be

contaminated with feces from poultry or other animals


Advice for Travelers Practice careful hand hygiene,

especially after handling raw poultry It is safe to eat poultry or eggs that

have been properly handled and cooked Monitor your health for 10 days after

returning Seek medical attention if symptoms of

fever or respiratory illness develop



Pandemic Influenza

Worldwide outbreak of a novel (new) influenza virus

Occurs infrequently and at irregular intervals

Unpredictable Potential for substantial impact

Morbidity (illness) and mortality (death) Social disruption Economic costs


20th Century Influenza Pandemics

1918-1919: “Spanish Flu” (H1N1) > 500,000 US deaths > 20 million deaths worldwide

1957-1958: “Asian Flu” (H2N2) 70,000 US deaths.

1968-1969: “Hong Kong Flu” (H3N2) 34,000 US deaths


Influenza Pandemic 1918


How does a pandemic happen?

4 factors must be present:1. Novel virus 2. Virus capable of causing disease in humans3. Susceptible population4. Virus that is transmissible from person to

person

Current avian influenza outbreak is not a pandemic


Where do new influenza strains come from?

1. Mixing of human and animal influenza strains

2. Adaptation of an animal strain to allow person to person spread


WHO Pandemic Phases


Issues of Concern Potential rapid worldwide spread due

to global trade and international travel

Medical resources may be insufficient Medical personnel at high risk of

infection Pandemic would likely be prolonged Community infrastructure disruption Major economic impact


Estimated Impact of “Medium-Level” Pandemic, US

As much as 35% of population could be affected ~ 47 million people

As many as 734,000 hospitalizations

As many as 207,000 deaths

Economic impact could range between $71.3 and $166.5 billion


On the bright side… Pandemic influenza planning is occurring at

the local, state, national and international levels

Surveillance for new influenza strains in birds and humans is ongoing to allow for early detection

Experience with SARS has led to increased awareness and preparedness to deal with global infectious disease emergencies

Medical care and isolation capabilities are more sophisticated than during 1918


Global Public Health Surveillance

International Health Regulations revised 2005 Defines Public Health Emergency of

International Concern (PHEIC) Contains a decision instrument to help

countries determine whether reporting to WHO is necessary

Includes a list of diseases to be reported immediately, even if single case

Encourages countries to consult WHO for events that may be of public health relevance



Pandemic Influenza Planning

Goals Limit total burden of disease (illness and death) Decrease social disruption Decrease economic loss

Engage all levels of health care system, public health, and emergency response

Include public and private sectors Key similarities (and differences) between

pandemic response and other health emergencies Planning, resources, and implementation


Local Planning an Influenza Pandemic

Surveillance recommendations Laboratory recommendations Antiviral plan Vaccine distribution plan Containment including isolation and

quarantine issues Surge capacity, mortuary issues, and mass

care Communications Public information


Vaccine and Antiviral Medications

Vaccine Will probably not be available in early stages of

a pandemic Even when vaccine does become available,

supplies will be limited Prioritization will have to occur

Antiviral medications Stockpiled supplies are limited but increasing Resistance may be a problem Prioritization will have to occur


Controlling a Pandemic Early identification and isolation of ill

people will be critical Close monitoring and possible quarantine

of exposed contacts Basic infection control measures “Social Distancing”

Public transportation Large gatherings/special events Schools


Preventing Spread of Influenza

Preventing illness: Wash your hands Stay away from people who are sick Get your flu vaccine!

If symptomatic with a respiratory illness: “Cover Your Cough” Wash your hands! Don’t visit friends or family in hospital or a long term

care facility If diagnosed with influenza:

Don’t go to work or attend school while symptomatic


Corporate (Workplace) Preparedness

Encourage respiratory and hand hygiene in the workplace

Ensure appropriate hygiene supplies and facilities are available

Discourage employees diagnosed with influenza from working while symptomatic

Plan for functioning with high levels of absenteeism

Mechanisms for employees to work from home, if possible


Preparedness in Schools Hygiene messages/posters Disease surveillance Systematic exclusion of sick students

and staff Consider the possibility of school

closures Who makes this decision? Mandatory closures vs self-shielding

behaviors Continuity of education




Personal/Family Emergency Preparedness

Prepare a disaster supply kit for 3 days (general emergencies)

Create a Family Emergency Plan Know where to access accurate

information


Personal and Corporate Antiviral Stockpiles – A Bad Idea!!!

Depletion of resources from the public sector

Inadequate supplies for treatment and prophylaxis during seasonal influenza outbreaks

Potential for misuse (wasting) during non-influenza respiratory infections

Potential for development of resistance Incomplete courses, incorrect dosing, sharing

Cost Inequitable distribution of drug Shelf life/expiration


For more information http://www.cdc.gov/flu/avian/

http://www.who.int

http://pandemicflu.gov/

Documents

Chicago Department of Public Health Local and Global Public Health Links: Preparation for an Influenza Pandemic Nicole J. Cohen, MD, MSc Chicago Department