1 Seasonal Influenza versus Avian Flu and Public Healths Role : Content adapted for BugLine from presentation by : Cassandra D. Youmans, MD, MPH, MS-HCM,

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Seasonal Influenza versus Avian Flu Seasonal Influenza versus Avian Flu and Public Health’s Roleand Public Health’s Role::

Content adapted for BugLine from presentation by :Content adapted for BugLine from presentation by :

Cassandra D. Youmans, MD, MPH, MS-HCM, FAAP

District Health Director

East Central Health District VI

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Epi TermsEpi Terms(www.healthyamericans.org)(www.healthyamericans.org)

• Endemic – expected or usual occurrence of disease

• Epidemic – unexpected or unusual occurrence of disease

• Pandemic – epidemic, but wider geographic area and larger population affected

• Shift – big change in a virus strain due to mutation

• Prevalence – existing disease in a given population at a given time

• Incidence – rate of occurrence of new cases of disease in a population

• Transmission – any means of spreading infectious disease to or among people

• Antigen – protein, usually foreign, that elicits a specific immune response

• Antibody – protein in the blood produced after exposure to an antigen

• Parasite/pathogen/germ – any organism causing disease

• Immunity – not susceptible to infection or disease

• Vaccine - a drug intended to induce active artificial immunity against a pathogen. It can be live or dead

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Active ImmunizationActive Immunization(www.swinton.net)(www.swinton.net)

• Attenuated (weakened) versions or strains of the pathogen– One dose typically induces a full antibody response or

memory– Example: MMR vaccine from wild strains of

measles/mumps/rubella viruses that are repeatedly passed through cell lines until non-pathogenic

• Killed (dead) versions or strains of the pathogen

– Whole pathogen; examples: Salk polio strain and pertussis vaccine

– Highly immunogenic part of the pathogen (toxoid vaccines)

– These do not multiply in the host; multiple doses are typically given to induce a full antibody response.

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Passive ImmunizationPassive Immunization(www.swinton.net)(www.swinton.net)

Passive immunization is different– Concentrated pathogen specific

antibodies (not weak or dead virus) are given to lesson the signs and symptoms of an infection or to provide short-term protection for several months

– Does not induce memory needed for long term protection

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Influenza VirusInfluenza Virus(Red Book 2003)(Red Book 2003)

• 3 virus/antigen types (A,B,C)– Each has subtypes– Only three subtypes known to be currently circulating among humans: H1N1,

H1N2, H3N2 (www.bt.cdc.gov)

• Epidemics are caused by types A and B– Antigenic shift has occurred only with Influenza A

• Antigenic shift - Major changes in these antigens lead to the emergence of new strains of the virus (the body cannot recognize or respond to the virus from past years)

– Influenza B is slower to change and has no subtypes• Antigenic drift – Minor changes cause seasonal epidemics (the body can still

recognize and respond to the virus based on past years)

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Clinical SymptomsClinical Symptoms(www.healthforums.com)(www.healthforums.com)

• Fever

• Cough

• Sore throat

• Muscle aches

• Eye infections

• Pneumonia

• Severe respiratory distress

• Life threatening complications

• Young infants – sepsis-like symptoms, croup, bronchiolitis, pneumonia

• Use Tylenol for children! Avoid Reyes Syndrome (associated with aspirin use, Influenza B, non-vaccine chickenpox.

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Seasonal Influenza Spread in HumansSeasonal Influenza Spread in Humans

• Person to person spread via secretions or direct contact with contaminated surfaces

• Most infectious 24 hours prior to symptoms

• 1–3 day incubation period

• Attack rate depends on immunity within the community

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Higher Risk GroupsHigher Risk Groups

• Cancer

• Diabetes

• Asthma

• COPD

• Cystic fibrosis• Infant BPD (Bronchopulmonary dysplasia)

• Congenital heart disease

• Sickle cell and other red cell shape abnormalities

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Diagnostic TestsDiagnostic Tests(Red Book 2003)(Red Book 2003)

• Nasopharyngeal (NP) swab/aspirate– Rapid screening test is reliable (sensitivity 45-90%,

specificity 60-95%).

• Can culture in the first 72 hours of illness– Virus concentration decreases after 72 hours– Egg or cell culture isolates virus within 2–6 days

• Can get 2 antibody titers– A 4-fold increase in titer from acute to

convalescent stages of illness is diagnostic

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Current Treatment RecommendationsCurrent Treatment RecommendationsFor For Type A andType A and B Influenza B Influenza

(Tarascon Pocket Pharmacopoeia 2005)(Tarascon Pocket Pharmacopoeia 2005)

• For treatment of Type A and B infections

• Begin within 2 days (48 hrs) of symptom onset

• Oseltamivir (Tamiflu)– For prophylaxis, not 100% effective

– Indiscriminate use may cause viral resistance

• Zanamivir (Relenza)– Not for prophylaxis, not for young children

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PandemicsPandemics(Pandemic Flu: What you should know. Q & A Volume I Winter 2006)(Pandemic Flu: What you should know. Q & A Volume I Winter 2006)

An average of 3 occur every century

• Five in the last 120 years

– 1889, 1900, 1918, 1957, 1958

• 1918 (Spanish Flu, 20-50 million died, 500,000 in US

• 1957 (Asian Flu, 4 million died)

• 1958 (6 million died)

Lower mortality because antibiotics available to treat secondary bacterial infections

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1957 Pandemic: Asian Flu1957 Pandemic: Asian Flu(Pandemic Flu: What you should know. Q & A Volume I Winter 2006)(Pandemic Flu: What you should know. Q & A Volume I Winter 2006)

– April 1957, a strain of influenza infected 250,000 people in Hong Kong

– US researcher, Maurice Hillerman, predicted the start of the Hong Kong outbreak signaled the next pandemic

– During the next 5 months, he persuaded 6 drug companies to produce influenza vaccine against the strain circulating in Hong Kong

– The virus entered the US in September 1957, 20 million people infected, 70,000 died

– Lesson learned: If enough vaccine is made in advance of a pandemic, lives will be saved

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PandemicsPandemics(Pandemic Flu: What you should know. Q & A Volume I Winter 2006)(Pandemic Flu: What you should know. Q & A Volume I Winter 2006)

– The best way to protect against a pandemic is a vaccine– The vaccine will have to contain the strain of influenza virus that is

causing the problem– An effective vaccine can’t be developed until the pandemic begins– 4 companies make influenza vaccine

• Sanofi Pasteur, GlaxoSmithKline, Chiron, and MedImmune– There is limited infrastructure to produce large quantities of vaccine,

therefore the vaccine would be rationed– Department of Health and Human services is developing a plan

(www.pandemicflu.gov/plan)

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Avian Influenza or Bird FluAvian Influenza or Bird Flu(www.bt.cdc.gov)(www.healthyforums.com)(www.bt.cdc.gov)(www.healthyforums.com)

• Type A Influenza Virus principally found in, and occurs naturally among birds

– Seasonal flu among birds

• H5N1 spreads rapidly among birds, but rarely in humans

– Wild birds carry the virus in their intestines, but rarely get sick

– Domestic birds - chickens, ducks, turkeys can get very sick and die

– 1997, Public Health Officials detected the strain in Southeast Asia, 170 people infected, 50% (85) died

• In affected countries, the virus has spread to other mammals like pigs, cats, and tigers.

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Domestic BirdsDomestic Birds(www.bt.cdc.gov)(www.bt.cdc.gov)

• Low virulence form - mild symptoms like ruffled feathers or drop in egg production

• High virulence form– spreads rapidly through flocks of poultry with mortality rates 90 to 100% in 48 hours

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Transmission in BirdsTransmission in Birds(www.healthforums.com)(www.healthforums.com)

• Infected birds shed virus in their saliva, nasal secretions, and feces

• Other birds are infected via direct contact with these secretions or excretions, or contaminated surfaces (cages, water, or feed)

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Avian Flu Spread in HumansAvian Flu Spread in Humans(www.healthforums.com)(www.healthforums.com)

• Direct contact with infected poultry or contaminated surfaces

• Risk factor – poultry worker, hand butchering infected foul

• Rare reports of the virus spreading from one person to another, and these cases have not been seen to continue beyond one person

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US Department of Agriculture Guidelines - US Department of Agriculture Guidelines - Common Sense At HomeCommon Sense At Home

(www.healthforums.com)(www.healthforums.com)

– Wash hands with warm water and soap for at least 20 seconds before and after handling food

– Keep raw poultry and its juices away from other foods

– Keep hands, utensils and surfaces such as cutting boards clean

– Uses a food thermometer to ensure poultry has been fully cooked

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Bird Flu and HumansBird Flu and Humans(www.bt.cdc.gov)(www.bt.cdc.gov)

• Prior to 1997, no human death associated

• No evidence that properly cooked poultry or eggs is a source of infection

• No human infections from eating poultry in affected countries

• H5N1 has not been detected in the US

• There have been no cases of infected poultry in the US

• In 2004, the US banned import of poultry from countries affected by Avian Influenza

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District VI Public Health Department Focuses District VI Public Health Department Focuses on Health and Wellnesson Health and Wellness

Medical Services Environmental Health

Emergency Preparedness

Promote Protect

Provide

3P’s

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Public Health’s Principle Role in Public Health’s Principle Role in Disaster MitigationDisaster Mitigation

• To assure access to Special Needs Shelters (SNS) when needed

• To directly administer or provide for administration of agent specific prophylactic and/or therapeutic pharmacologys to mass populations

• To support local and district EOC emergency preparedness efforts

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Pre Event: Is ALL about education!Pre Event: Is ALL about education!Preparation begins with education prior to a disaster• Seek information about potential hazards within your

community.

Then you can:• Secure your safety• Secure your family and home• Encourage friends, peers, community to do the same• Plan for two-way communication with emergency

personnel and family, and have contingencies built in• Be flexible• Be prepared

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Public Health ChallengePublic Health Challenge

• Risk of a shift: H5N1 virus might exchange genes with a human virus strain or mutate into a form that is easily spread to and among humans

• Rare in humans, therefore our immune systems have not been exposed to be able to develop enough of an immune response to fight it, an influenza pandemic could begin – The seasonal human influenza vaccine will not provide protection– H5N1 specific vaccines have been in development since April 2005– Clinical trials are underway – Antiviral drugs are being studied for efficacy

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Pandemic Flu Impact AssumptionsPandemic Flu Impact Assumptions(Pandemic Flu Response Standard Operating Guide (SOG)(Pandemic Flu Response Standard Operating Guide (SOG)

Assuming Georgia makes up approximately 3 % of the US Population,Estimated population is 9.1 million

Characteristics Moderate Severe Moderate Severe

Illness

Outpatient Care

Hospitalization

ICU care

Mechanical ventilation

Deaths 209,000 1,903,000 6,270 57,090

64,875 742,500 1,946 22,275

128,750 1,485,000 3,863 44,550

865,000 9,900,000 25,950 297,000

USA GA

90 million

45 million

2.7 million

1.35 million1.35 million

(50%)

2.7 million (30%)

90 million (30%)

45 million (50%)

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Consider the expected impact on area finances and infrastructure due to flu illness, absentees, deaths!

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Disasters vary, but planning questions Disasters vary, but planning questions remain the sameremain the same

• Who?

• What?

• Where?

• When?

• How?

• Why?

Drills Offer Opportunities to Exercise Plans, Modify, and Adjust.

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Successful Disaster Management Requires Successful Disaster Management Requires Partnership & IntegrationPartnership & Integration

• Volunteer Medical Reserve corps

• Local emergency operations centers

• Academic medical centers

• Community health centers

• Federally Qualified Health Centers

• Faith based organizations

• Nursing schools

• ESF8

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East Central Health District Collaborators:

Melba McNorrill, RN Child Health Coordinator

Gary Zgutowicz, Emergency Preparedness Coordinator

Donna Scott, Clinical Services Coordinator

Sadie Stockton, TUPS/Chronic Disease Prevention Coordinator

Jodie Reece, IT Director

Helen Smith, Administrative Assistant to the District Health Director

County Facility Managers and staff

Contacts:• Georgia Department of Human

Resources, Division of Public Health; www.dhr.georgia.gov; www.health.state.ga.us;

• East Central Health District Emergency Preparedness ; 706-729-2190

• East Central Health District, www.ecphd.com, 706-667-4250

• Centers for Disease Control and Prevention; www.cdc.gov ; 1-888-232-4674