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The Potential Threat of Influenza. Flu Terms Defined. Seasonal (or common) flu is a respiratory illness transmitted person-to-person. Most have some immunity, and a vaccine is usually available.
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Flu Terms Defined • Seasonal (or common) flu is a respiratory illness transmitted person-to-person. Most have some immunity, and a vaccine is usually available. • Pandemic flu is virulent human flu that causes a global outbreak of serious illness. There is little natural immunity, and spreads easily from person-to -person. There is no vaccine available. • Avian (or bird) flu is caused by influenza viruses that occur naturally among wild birds. The H5N1 variant is deadly to domestic fowl and can be transmitted from birds to humans. There is no human immunity, and no vaccine is available.
Disaster vs Pandemic Thailand Tsunami 2004 Khao Beach
Widespread geographic impact Occur in multiple waves over ~one year Invisible evidence Human casualties predominate State/federal response may be very limited Widespread economic crisis Limited in scope to a certain area Limited in time from minutes to days Visible evidence Material casualties predominate Can count on local material aid and state/federal response Localized economic impact Disasters vs Pandemics
Seasonal Influenza Overview • Respiratory infection • Transmission:contact with respiratory secretions from an infected person who is coughing and sneezing • Incubation period:1 to 5 days from exposure to onset of symptoms • Communicability:Maximum 1 to 2 days before to 4 to 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
Impact of Human InfluenzaSeasonal Epidemics in United States Deaths ~36,000 Hospitalizations ~200,000 Physician visits ~ 25 million Infections and illnesses 50 - 60 million Thompson WW et al. JAMA. 2003;289:179-86. Couch RB. Ann Intern Med. 2000;133:992-8. Patriarca PA. JAMA. 1999;282:75-7. ACIP. MMWR. 2004;53(RR06):1-40.
Seasonal vs Pandemic Flu Seasonal Flu • Annually fall • Known virus • Vaccine available (usually) • High mortality young & old esp. w/ health problems Pandemic Flu • Irregular intervals anytime of year • Novel virus • No or mismatched vaccine • High attack rate and mortality in 15–50 year olds; mortality in young similar to seasonal flu
Influenza Types • Type A • Epidemics and pandemics • Animals and humans • All ages • Type B • Milder epidemics • Humans only • Primarily affects children
Influenza Virus Composition Type of nuclear material Neuraminidase Hemagglutinin A/Beijing/32/92 (H3N2) Virus type Geographic origin Strain number Year of Isolation Virus subtype
Influenza Antigenic Changes Structure of hemagglutinin (H) and neuraminidase (N) periodically change: • Drift:Minor change, same subtype • In 1997, A/Wuhan/359/95 (H3N2) virus was dominant • A/Sydney/5/97 (H3N2) appeared in late 1997 and became the dominant virus in 1998 • Shift: Major change, new subtype • H2N2 circulated in 1957-67 • H3N2 appeared in 1968 and replaced H2N2 • Pandemic potential
Mechanisms of Antigenic Shift Reassortment in humans Direct Infection Avian virus Indirect Infection Human virus Reassortment In pigs
Countries with H5N1 Influenza in Animals & Humans Countries with H5N1 influenza in animals Countries with H5N1 influenza in humans Through December 28, 2006
The H5N1 Flu Threat to Humans • A new virus to which humans have no immunity — Yes • The virus causes significant human illness or death — Yes • The virus spreads easily from person-to-person — NO The Avian Flu (H5N1) virus has 2 out of 3 of these today…
Influenza Pandemics of the 20th Century http://www.who.int/csr/disease/avian_influenza/en/index.html
Pandemic Flu “Waves” • Flu “waves” last 2-12 weeks • Waves fade then reoccur multiple times • Peak of waves lasts 1-3 weeks • Some locations hit when others are not • Secondary waves are usually the worst
Pandemic flu - 1918 • Healthcare system overwhelmed • Churches and schools shut down • Hysteria and panic reigned • Telecommunication and transportation failed • Police protection failed • Deathcare system overwhelmed
Scared, Sick and Dying Personnel • Up to 30-50% could be infected over a 12-15 month period. • Some staff members will die. • Up to 50% of a workforce can be absent at the peak of a wave – either ill, caring for sick family members, lacking transportation or scared. US Army Hospital – Aix-Lex-Bains, France 1918
Estimated Episodes of Illness, Healthcare Utilization and Death for Texas*
Key Steps for Government Business Continuity Planning 1. Prioritize critical functions • Life, Health, Safety (Police, Fire, EMS, Public Health, Hospitals) • Identify functions that support life, health and safety actions (Communications, data management, facility operation, payroll) • Identify functions that are critical to the mission of an agency
Key Steps for Government Business Continuity Planning • Identify staff needed to carry out critical functions • Identify functions that could be suspended • Build depth through cross training • Plan for alternative work schedules • Explore telecommuting capabilities – large scale
Pandemic Influenza PreparednessKey Steps for Government Agencies • Engage businesses, agencies and organizations that depend on your services or on whom you depend • Involve leadership - identify actions they may take in response to a pandemic event
Pandemic Influenza PreparednessKey Steps for Government Agencies • Determine an incident command structure for agency leadership with at least 2 levels of back-up • Educate employees as to plans • Encourage personal preparedness
Pandemic Influenza Response Plan - Next Steps • Develop agency standard operating procedures to fulfill roles assigned by the State Pandemic Influenza Response Plan • Brief leaders • Conduct training and exercises over and over; internally as well as opportunities for external exercise participation
Pandemic Influenza ProjectionsAustin area 1.3 million people • No. of casualties 1st wave 2nd wave • Illnesses 326,657 65,332 • Hospitalizations 13,067 2,614 • Deaths 5,553 1,111 Source: Austin Travis County Health Department
Number of Confirmed Human Cases of Avian Influenza A/(H5N1) — Worldwide (by 22 January 2007) Total number of cases includes numberof deathsWHO reports only laboratory-confirmed cases