Avian Influenza: Bird of a Different Feather A Primer to Pandemic Influenza Preparedness Office of Surveillance and Public Health Preparedness Houston Department of Health and Human Services
Agenda • Medical overview • Business continuity planning • What HDHHS is doing
Types of Influenza • Seasonal Influenza: Annual event (type A and type B strains) • Seasonal (or common) flu is a respiratory illness that can be transmitted person to person. Most people have some immunity, and a vaccine is available. • Avian Influenza: flu in bird populations (wild and domestic) • Avian flu is caused by influenza viruses that occur naturally among wild birds. The H5N1 type A variant is deadly to domestic fowl and can be transmitted from birds to humans. There is no human immunity and no vaccine is available. • Pandemic Influenza: a new type A strain that causes serious illness and death, and spreads easily from person to person worldwide • Pandemic flu is virulent human flu that causes a global outbreak, or pandemic, of serious illness. Because there is little natural immunity, the disease can spread easily from person to person. Currently, there is no pandemic flu.
Seasonal Influenza • Viral Infection of the respiratory tract • Occurs seasonally • Three types A, B and C • Particular nomenclature • Originates in wild aquatic birds • Evades immunity through drift and shift
Pathology of Influenza Infection 3. Replication 1. Binding to Sialic Acid 2. Entering Cell 4. Release From Cell
Clinically Relevant Influenza Viruses Type A Potentially severe illness Epidemics and pandemics Rapidly changing Type B Usually less severe illness Epidemics More uniform Type C Usually mild or asymptomatic illness Minimal public health impact
RNA Hemagglutinin Neuraminidase Antibodies Sialic Acid Antigenic Drift
Avian Influenza • Influenza A subtype • Designated H5N1 • Related to bird migratory patterns, smuggling and travel • Presence of the virus does not signal avian pandemic • Human infections related to close contact • No evidence of sustained human-to-human transmission
Pandemic Influenza • Global outbreak of disease that occurs when a new influenza A virus appears or “emerges” in the human population • May be of avian origin • Caused by new subtypes that have never circulated among people, or by subtypes that have not circulated among people for a long time • Characterized as highly contagious, spreading from person to person, worldwide and causes social and economic disruption • Occurs approximately three times every century
20th Century Influenza Pandemics 1918: “Spanish Flu” 1957: “Asian Flu” 1968: “Hong Kong Flu” 20-40 million deaths 1 million deaths 1 milliondeaths H3N2 H2N2 H1N1 H1N1 1920 1940 1960 1980 2000
Influenza Statistics • 5% to 20% of population every year • >200,000 hospitalizations due to complications • 10,000 deaths per epidemic are common • 20,000 to 40,000 deaths during recent epidemics MMWR. 2000;49:1.
Economic Cost of Influenza • Total annual costs of influenza are estimated at $14.6 billion in the US • 10%: Direct costs of increased medical care • 90%: Indirect costs (lost productivity, employee absenteeism) American Lung Association. Fact Sheet – Influenza. Available at http://www.lungusa.org/diseases/influenza_factsheet.html.
Surveillance • Three systems coordinated by the CDC • Pneumonia and influenza deaths • Influenza-like illnesses • Physician reporting • Syndromic surveillance
Pneumonia and Influenza Mortality in 122 US Cities CDC. 1999-2000 influenza season summary. Available at: http://www.cdc.gov/ncidod/diseases/flu/bigpi.htm.
Nasopharynx Trachea Signs and Symptoms of Influenza • Sudden fever, usually over 100°F • Muscle aches and pains • Nasal congestion • Dry cough • Chills and/or sweats • Headache • Sore throat • Potentially severe, persistent malaise • Substernal soreness, photophobia, and ocular problems
Risk Factors for Influenza Complications (CDC) • Age 50 yrs • Residence in nursing home/chronic care facilities • Chronic pulmonary disease (eg, asthma, COPD) • Chronic cardiovascular disease • Chronic metabolic diseases, renal dysfunction, hemoglobinopathy • Immunosuppression • Long-term aspirin therapy (ages 6 mos-18 yrs) • Second or third trimester pregnancy MMWR. 2000;49:6-7.
Prevention and Treatment • Vaccination • Antivirals
Inactivated Influenza Virus Vaccine Content Updated yearly to protect against anticipated strains, consists of type A (2) and type B (1) Process Grown in embryonated chicken eggs and formalin inactivated
Live Attenuated Influenza Vaccine (LAIV) • Licensed for use in the U.S. begins in 2003 • The protective mechanisms are not completely understood • Children and adults can shed vaccine viruses for >2 days after vaccination • Advantages include: • Induce a broad mucosal and systemic immune system • Acceptability of an intranasal route of administration
Influenza Virus Vaccine • Efficacy • Varies with age and immunocompetence • Depends on match between projected vs actual strains • Children/Teens • Stimulates high HA-inhibition antibody titers • Prevents infection • Elderly • Produces lower HA-inhibition antibody titers • May not eliminate URTI susceptibility • May reduce LRTI morbidity/mortality MMWR. 2000;49:5.
Effectiveness of Influenza Vaccine • Most effective (70%-90%) in preventing illness in persons aged <65 yrs • 30%-40% in preventing illness in frail elderly • Overall significantly protects against the severe complications of influenza: hospitalizations and death
Get the Influenza Vaccine • October through November in the Fall • Only one shot is needed for older children and adults • Two does may be required for unvaccinated children aged less than nine years
Who Should Receive Influenza Vaccine (CDC) • Persons aged 50 yrs • Persons at increased risk (age 6 mos) • Hospital and outpatient employees • Nursing home employees with patient contact • Home health care providers working with high-risk persons • Household members of high-risk persons • Pregnant women in 2nd or 3rd trimester • Persons desiring to avoid influenza infection MMWR. 2000;49:6-7.
Side Effects of the Influenza Vaccine • Soreness at injection site (common, mild, and transient) • Systemic and febrile reactions, esp in young children (infrequent) • Immediate hypersensitivity reactions to egg protein (rare) • Guillain-Barré syndrome (rare) MMWR. 2000;49:11-12.
Who Should Not Receive the Vaccination • An allergic reaction to chicken eggs (welts, tongue swelling, difficulty breathing, loss of blood pressure, etc.) • A previous serious reaction to an influenza shot • A rare paralytic disorder called Guillain-Barré Syndrome which was thought to be cause by a pervious influenza shot • A current illness with fever
Influenza A Influenza A and B • Amantadine • Rimantadine • Zanamivir • Oseltamivir Phosphate Treating Influenza with Antivirals
What To Do If You Develop Influenza • If symptoms present less than two days, discuss specific antiviral treatment with your physician • For fever and muscle aches: • Aspirin if you are 18 years of age or older • Or Acetaminophen • Or Ibuprofen • Liquids and nutrition • Rest • See your physician if symptoms worsen
Prevention: Simple Steps • Vaccine • Hygiene • Public Health Measures • Cover Your Cough. • Wash Your Hands. • Get your seasonal flu shot. • Keep all your immunizations current.
Reputation People Organization Protect Information Customers Operation Goals • Containment of disease • Reduction of the impact by controlling the spread of disease • Maintenance of essential services
Evaluation • Identification of essential business activities • Mitigation of business / economic disruptions • Minimizing illness
Strategy • Communication • Containment • Continuity
Programs Insurers Health Plans Materials Healthcare Providers Strategies PH Agencies Communication Plan Other Business Entities Communication Internal Communication / Education External Coordination
Containment • Restrict workplace entry • Emphasize personal hygiene • Social distancing • Manage staff
Cover Your Cough • Cover nose and mouth when sneezing • Use a tissue and dispose once used • Keep hands away from nose, mouth and eyes • Ask people to do the same
Hand Washing • The most important action can do • Soap and water (10-20 seconds) • Alcohol-based sanitizer (15 seconds)
Work Place Disinfectant • Influenza viruses inactivated by alcohol or chlorine • Surfaces touched by hands should be cleansed daily • 1:5 dilution of hospital grade bleach • Granular chlorine • 70% isopropyl alcohol • 60% ethyl alcohol
Social Distancing • Avoid face-to-face meetings • Avoid congregations • 3 Feet rule • Ghost shifts
Manage Staff • Encourage, manage and track influenza vaccination • Establish healthcare resources • Flexible scheduling • Encourage working from home • Oversee travel
Continuity • Identification of core people and skills • Business planning for absence • Knowledge management • Communication
Identification of Core People and Skills • What are the essential parts of the business • Who are the core people required to keep the business running • What are the core skills required • Who are the back-ups • Who will manage the pandemic component
Business Planning for Absence • What is the minimal number of staff required • Where can additional staffing be found • Can operations be shifted • Plan for essential incidentals: food, water, gas
Knowledge Management • Develop a plan • Key operating and emergency management information needs to be readily accessible • Implement exercises and drills to practice • Test plan regularly