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Pandemic Influenza. Influenza. Outbreaks yearly, usually in winter months Illness more severe for very young, elderly, or those with pre-existing health conditions Yearly, 5-20% of population get the flu Annually causes >200,000 hospitalizations in US 36,000 deaths yearly in US.
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Influenza • Outbreaks yearly, usually in winter months • Illness more severe for very young, elderly, or those with pre-existing health conditions • Yearly, 5-20% of population get the flu • Annually causes >200,000 hospitalizations in US • 36,000 deaths yearly in US
Influenza Prevention • Yearly influenza shot • Avoid those who are ill • Wash your hands • Antivirals (in special circumstances) If you are ill--don’t come to work, cover coughs and sneezes.
Influenza Virus types • Type A: Infects humans and other animals • More severe illness • Causes regular epidemics; can cause pandemics • Type B: Infectious only to humans • Causes epidemics, but less severe illness
Influenza • Influenza A is subtyped by surface proteins • Hemagglutinin (H) • 16 different types • Helps virus enter cells • Neuraminidase (N) • 9 different types • Helps virus leave cell to infect others
Influenza • All known subtypes of Influenza A found in birds • H5 and H7 cause severe outbreaks in birds • Human disease usually due to H1, H2, H3 and N1 and N2.
Influenza The flu virus constantly changes • When it does, vaccines will be less efficient • Immune system may be unable to recognize new virus • No immunity in population for new virus—potential for pandemic
Inactivated trivalent vaccine (killed vaccine) 2 A, 1 B Effectiveness of vaccine depends on “match” between circulating strains and those in vaccine Vaccine Development 2005–2006 Influenza Season A/New Caledonia/20/99-like A/California/7/2004-like (H1N1) (H3N2) InfluenzaProtection B/Shanghai/361/2002-like
Prior Year January February March April Surveillance on circulating strains Selection of specific strains Preparation and distribution of virus stock to manufacturers Seed pools inoculated into eggs n engl j med 351;20 www.nejm.org november 11, 2004
May June July August September October Harvest and concentration of fluids Vaccine inactivated and purified Vaccine blended, content verified Packaging, labeling, delivery n engl j med351;20 www.nejm.org november 11, 2004
Influenza—Vaccine Production • Flu vaccines first produced in 1940s • 2 manufacturers in US for flu vaccine • 80 million doses produced by late September • 6-9 months to produce vaccine
Influenza Pandemics • What is a Pandemic? • Outbreak in wide geographic area (global) • Effects large # of people with serious illness • Usually a new virus or one which population has not had exposure in a long time • May have rapid spread • May occur in waves
Seasonal Occurs every year Occurs during winter (usually Dec-Mar) Most recover in 1-2 weeks without tx Very young, very old, ill most at risk of serious illness Pandemic Occurs infrequently(3 per century) Occurs any time of year Some may not recover, even with tx People of all ages may be at risk Seasonal Flu vs Pandemic Flu
Pandemic Influenza • Past Pandemics: • 1968 Hong Kong Flu (H3N2) • 1957 Asian Flu (H2N2) • 1918 Spanish Flu (H1N1)
1918-1919 influenza pandemic • Worst of past century • Estimated 20-40% of world population ill • 40-50 million people died worldwide • 600,000 or more deaths in US • High mortality in young adults
Why did young people die? • Over-reaction by the immune system called “cytokine storm” • Those with the strongest immune systems affected • Older people and youngest often die of bacterial pneumonia complicating flu -- treatable now with antibiotics • Even in 2005, no good treatment for “cytokine storm.”
Infectious Disease Deaths 1900’s Deaths per 100,000 per year 1957 1968 1918
H5N1 Avian Influenza • Hong Kong 1997 • 18 human cases, 6 deaths • 1.4 million birds destroyed • Dec. 2003: Asia • Ongoing extensive outbreak in poultry • Limited human to human transmission • 125 human cases, 64 fatal • July-Aug 2005 Kazakhstan, Russia • October 2005 Turkey, Romania, Russia
H5N1 Symptoms • Symptoms (human) • Fever • Shortness of breath • Cough • Pneumonia • Acute Respiratory Distress • Diarrhea, sometimes severe • Life-threatening complications
Concern with Avian Influenza • Virus mutates rapidly • Has shown ability to acquire genes from viruses infecting other species • H5N1 has acquired some of genetic changes in the 1918 virus associated with human-human transmission • Causes severe disease in humans • High fatality rate
If it happens soon….. • There will be little or no vaccine until 6 - 9 months after the outbreak begins • There will be very limited supplies of antiviral medicines for treatment (for 1% of populations, perhaps less). • All communities hit a about the same time • We need a plan for the short-term that assumes no effective shots or Rx
Why at LESS risk in 2005 • Antibiotics for bacterial pneumonia complications of influenza • Some antiviral medicines • IV fluids, ventilators • Greater ability to do surveillance, confirm diagnosis of flu
Why at LESS risk in 2005 • Rapid means of communications - internet, TV, radio, email • More effective personal protective equipment • Fewer people living in each household and more rooms.
Why at MORE risk in 2005 • A lot more international travel • 10 times more people in Larimer County, contact with far more people daily • Very little surge capacity in health care today • More elderly and immune-compromised people in population
Why at MORE risk in 2005 • Much less self-sufficient than in 1918’s (households and businesses) • Far more manufactured goods and raw materials come from distant areas, especially Asia • “Just-in-time” ordering of needed supplies instead of warehousing critical items on site
Why at MORE risk in 2005 • Unlike 1918, today’s society not used to rationing, sacrifice.(In 1918, because of WWI, fuel, coal, and food were already being rationed, and community groups, like the Red Cross, were very active supporting the war effort)
Overall, are we at more or less risk? • Up to individuals, communities, states, and nations to decide as they plan for a possible pandemic
What might occur - fictional but possible • Closing of borders, shutting down trade • Fuel shortages/restrictions due to in oil imports • Closing of schools, events, and businesses where large numbers of people congregate • Businessses/workers upset about loss of income
What might occur • High mortality, especially among young adults • People working at home when possible; others taking paid or unpaid leave • Absenteeism of 30% to 50% • High numbers of cases, hospitalizations, and deaths
What might occur • Not enough hospital beds, health care workers, or ventilators • High numbers of cases and hospitalizations. Death rates - 2.5% • Death rate for pregnant women is 20% • Inadequate amounts of antiviral meds, leading to violence at treatment sites
What might occur • Sick people who live alone, or with small children only, in dire straits • Young children trying to take care of sick parents, with no support • Children neglected because parent(s) too sick to provide care • Orphaned children whose parent(s) have died
What might occur • Mortuaries and crematoria unable to keep up with deaths • Funeral home workers unwilling to handle corpses of influenza patients • Makeshift hospitals established in churches and schools • Shortages of fuel, food, essential supplies; prices skyrocket.
What might occur • Utilities having trouble with staff shortages, inability to replace supplies and parts. Spot failures occurring. • Care shifted from hospitals to being taken care of by family/friends/people in neighborhood. • Some neighborhoods organized, collaborative; others disorganized with individuals hoarding
What might occur • Protective face masks that sold for $1 are now going for $20 each • Sanitizers and chlorine are sold out of the stores • Availability of other Rx drugs is reduced • Flu outbreak severe in detention center, with 1/2 the usual number of staff
What might occur • Courts largely shut down; no one willing to serve on a jury • Fear, distrust, mourning/depression, are widespread • Church facilities are closed when people most need spiritual comfort • Some flee cities to National Forests to wait out the outbreak
What might occur • In the end, after several waves and 3-4 months, the outbreak is declared to be over in Larimer County. • Over 80,000 became ill and over 2,000 deaths occurred in about 12 weeks. • Great economic loses from closed businesses.
What might occur • 12,000 needed hospitalization, although many were cared for in the community • With the completion of McKee’s new wing AND the completion of Medical Center of the Rockies, Larimer County will have about 635 licensed hospital beds.
Can we maintain our utilities? • Recent disasters have showed us the need for water, power, telecommuni-cations, heat in an emergency • Can they operate with 50% of staff? • Do they stockpile materials and parts to ensure operation for 90-120 days?
Will transportation/trade problems impact food supply? • Typical household has food on hand to last 3 days. • Few families have emergency reserves for a prolonged period • Low-income least able to set supplies aside for an emergency • Prices will rise quickly in emergency.
Who will provide health care? • Health workers will be disproportion-ately exposed and may become ill • Some will not show up due to fear • Some will not be able to leave sick family members, children out of school • Little or no surge capacity; nursing shortage; ? future of MRC?
Who will help us? • Little or no state and federal assistance • Local government also limited in what it can do to assist citizens • Churches, neighbors, friends and families will need to help each other out • Vulnerable groups will need extra assistance • Advance planning and stockpiling of necessities could help.