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“Pandemic Influenza, Government, and Business: Balancing Public Health and Economic Risks” Douglas Ball, MD, MA Department of Community and Preventive Medicine University of Rochester School of Medicine [email protected] Overview • • • • Some things about Influenza A Some things about Pandemics Some things about Disease Control Planning for Pandemics • • • • What to expect from a pandemic. What to expect from the Government. What to expect from the workforce. How to plan. • Resources Influenza A virus subtypes: • 16 HA antigens (H1 to H16) • 9 NA antigens (N1 to N9) • Human disease historically • HA (H1, H2, and H3) • NA (N1 and N2) • More recently, human disease from avian origin • HA (H5, H7, and H9) Two Very Important Properties • "Antigenic drift" refers to the process of small genetic changes that influenza viruses continuously undergo from year to year, which necessitates the development of new vaccines annually. • "Antigenic shift" refers to substantial genetic changes caused by the process of genetic reassortment. Avian influenza • Influenza A subtypes that primarily affect birds. • H5N1 • 191 human cases, ~50% case mortality rate • New York State Department of Agriculture and Markets • The New York State Department of Environmental Conservation’s Wildlife Pathology Unit What is Pandemic Influenza? • Highly pathogenic for humans. • Efficiently transmitted between humans. • Genetically unique. Routes of transmission • • • • Direct and indirect contact Droplet Airborne How much transmission occurs before symptoms are present??? WHO Pandemic Phases Phase Definition 1 Inter-pandemic Period No new flu subtypes in humans Possibly present in animals Risk to humans is low. 2 Inter-pandemic Period No new flu subtypes in humans A circulating animal flu subtype poses a substantial risk of human disease. WHO Pandemic Phases Phase Definition 3 Pandemic Alert Period Human infections with a new subtype, No human-to-human spread, or rare instances of spread to a close contact. 4 Pandemic Alert Period Small clusters, limited human-to-human transmission Spread is highly localized: Virus is not well adapted to humans. 5 Pandemic Alert Period Larger clusters but human-to-human spread still localized: Virus becoming better adapted to humans 6 Pandemic Period Increased and sustained transmission in general population. Historical pandemics • Three pandemics occurred during the 20th century: • 1918-19: Spanish Flu. • 1957-58: Asian Flu. • 1968-69: Hong Kong Flu. Historical pandemics: 1918-1919 • 1918-1919 (Spanish Flu) • Strain was H1N1, with probable avian origin • 500 million ill worldwide • 40-50 million dead worldwide • Attack rate: 40% of people in exposed populations fell ill • Case fatality rate: 2.5-5% of ill died as a result of the illness 1918 Pandemic waves Taubenberger JK, Morens DM. 1918 Influenza: the Mother of All Pandemics. Emerging Infectious Diseases 2006;12:17. 1918 Pandemic distorted case mortality Taubenberger JK, Morens DM. 1918 Influenza: the Mother of All Pandemics. Emerging Infectious Diseases 2006;12:20. Historical pandemics: 1957-58 • 1957-58 (Asian Flu) • Cause was H2N2, via a re-assortment event • 2 million dead worldwide • Attack rate: 20-70% of people in exposed populations fell ill • Case fatality rate: 0.1-0.2% of ill died as a result of the illness Historical pandemics: 1968-69 • 1968-69 (Hong Kong Flu) • Strain was H3N2, via a re-assortment event • 1 million dead worldwide • Attack rate: 15% of people in exposed populations fell ill • Case fatality rate: 0.1-0.2% of ill died as a result of the illness Pandemic features • Great variation in mortality, severity of illness, and patterns of spread. • Rapid surge in cases and exponential increase over a very brief time, often measured in weeks. • Severe disease in non-traditional age groups, namely young adults, is a major determinant of a pandemic's overall impact. • Subsequent waves more severe then primary wave. Disease control strategies • Vaccination • Pharmacologic • Prophylaxis • Treatment • Non-pharmacologic • Isolation and Quarantine • Social Distancing • Hygiene • Decontamination • Personal Protective Equipment Pandemic vaccine • Annual vaccine is trivalent (3 strains), pandemic vaccine will be monovalent. • Production using current technologies would likely take 4-5 months may not be available before 1st pandemic wave • There will be vaccine shortages initially • 2 doses may be necessary to ensure immunity • H5N1 Vaccines are in clinical trials Pharmacologic prophylaxis and treatment of influenza • Two groups of antiviral agents are available for treatment and prophylaxis of influenza • adamantanes • amantadine • rimantadine • neuraminidase inhibitors • oseltamivir • zanamivir Isolation and quarantine • Only shown to be effective in preventing transmission in closed settings. • Recommended if pandemic influenza strain is highly localized and limited. Limitations for Influenza • Short incubation period. • Possible pre-symptomatic spread. • Possible asymptomatic illness. Social distancing and hygiene • Limited success during past pandemics. • Wearing masks in public apparently helpful. • Hand washing and respiratory hygiene/cough etiquette may help, but benefit is undemonstrated. Decontamination • “The influenza virus is extremely sensitive to almost any disinfectant. However, it is very difficult to inactivate the virus if it is in organic material, such as feces.” Disinfectants that will kill avian influenza virus: • Any detergent • Formaldehyde • Bleach • Ammonia • Acids • Heating to 90ºF for 3 hours, 100ºF for 30 min. • Drying • Iodine containing solutions Cardona C. UC Davis Veterinary Medicine Extension. AI Recommendations. Available at: http://www.vetmed.ucdavis.edu/vetext/INF-PO_AI.html Accessed February 06, 2006. Surgical masks • FDA Surgical Mask Approval Criteria “A surgical mask covers the user’s nose and mouth and provides a physical barrier to fluids and particulate materials.” “A surgical respirator is fitted to the user’s face, forming a seal that provides a physical barrier to fluids, particulate materials, and aerosols.” • NYS DOH “Wear a surgical or procedure mask for close contact with infectious patients (i.e., within 3 feet).” Ways that pandemic planning is different • Influenza pandemics are expected but arrive with very little warning. • Outbreaks can be expected to occur simultaneously throughout much of the U.S. • The effect of pandemic influenza on individual communities will be relatively prolonged (weeks to months) in comparison to disasters of shorter duration. Ways that pandemic planning is different • The number of persons affected will be high. • Effective preventive and therapeutic measures, including vaccine and antiviral agents, are likely to be delayed and in short supply. • There may be significant shortages of personnel in other sectors that provide critical public safety services. A question of risk Risk =Hazard X Probability Which model? • Department of Health and Human Services Pandemic Plan (and NYS DOH plan): • Very detailed, mild and severe scenario. • Duration of absenteeism not quantified. • 10% worker absence for child care and care of ill relatives suggested. Which model? • Congressional Budget Office • Comprehensive; mild and severe scenarios. • Includes numbers of days workers expected to miss. Which model? • FluSurge 2.0 • A CDC modeling tool. • Does not model the DHHS-stated planning assumptions. Comparison For Monroe County • DHHS Assumptions: • 30% overall attack rate. • 2.5% case mortality rate. • For population of 738422, there will be 5, 538 deaths. • FluSurge 2.0 • 35% overall attack rate. • For population of 738422, there will be 1,158 deaths in the worst case scenario. Congressional Budget Office Severe Pandemic Projection for Monroe County: • 220 thousand will fall ill (30% of total population) • 5,500 will die (2.5% of those who fall ill) • Workforce Effects: • 30% of the workforce will be affected. • For surviving ill, average time away from work will be 3 weeks. • 2,750 workers will die (0.75% permanent reduction of the workforce). Likelihood of a pandemic • Pandemics have occurred an average of every 24 years over the last 300 years. • Large HPAI pandemic may be a harbinger of a human pandemic: • • • • now endemic in eastern Asia. expanding mammalian host range and geographic extent. high case-fatality rate. two recent mutations ->better adapted to humans. Travel restrictions • Point-of-entry screening. • Isolating persons and identifying and quarantining contacts. • Limiting or canceling nonessential travel. • Isolating ill arriving passengers on flights and quarantining passengers and crew. • Closing mass transit systems and interstate bus and train routes. Containment strategies for different groups 1) Individuals or groups of exposed persons: isolation and quarantine. 2) Entire communities • • • Promotion of community-wide infection control measures including respiratory hygiene/cough etiquette, hand hygiene, and avoiding public gatherings. Snow days and self-shielding Closure of office buildings, shopping malls, schools, and public transportation are potential community containment measures during a pandemic. Workforce • Marked reduction in workforce due to: • Fear of contracting illness and fear related behaviors. • Child and elder care obligations and absences. • Personal illness and absence. • Deaths. Common sense planning • Identify essential employees and other critical inputs. • Provide sufficient and accessible infection control supplies in all business locations. • Establish policies for employees who have been exposed to pandemic influenza, are suspected to be ill, or become ill at the worksite. • Anticipate employee fear and anxiety, rumors and misinformation, and plan communications accordingly. Other less obvious issues • Establish policies for flexible worksite and flexible work hours. • Establish policies for preventing influenza spread at the worksite. • Evacuate employees working in or near an affected area. Other less obvious issues • Establish policies for employee compensation and sickleave absences unique to a pandemic: • “non-punitive”. • “liberal leave”. • Self-shielding. • Caring for well children home from closed schools. • Quarantine. Players on your team • Your Company • • • • • Line Management Human Resources Occupational Health Logistics Information Technology • Public Health Department Local Health Departments • Monroe County Health Department COMMISSIONER: Andrew Doniger, MD, MPH PHONE: 585-753-2991 E-mail: [email protected] • Livingston County Health Department PUBLIC HEALTH DIRECTOR: Joan H. Ellison PHONE: 585-243-7270 E-mail: [email protected] • Orleans County Health Department PUBLIC HEALTH DIRECTOR:/ DIR. OF ENVIRON. HEALTH: Andrew Lucyszyn E-mail: [email protected] • Ontario County Comm. Health Services PUBLIC HEALTH DIRECTOR: Jody Gray, RN, MSN PHONE: 585-396-4343 E-mail: [email protected] • Genesee County Public Health Department PUBLIC HEALTH DIRECTOR: Christopher M. Szwagiel, MS, MPH, DrPH PHONE: (585) 344-2580 x 5496 E-mail: [email protected] • Wayne County Public Health Service PUBLIC HEALTH DIRECTOR: Linda Michielson, RN, MS, ANP PHONE: 315-946-5749 E-Mail: [email protected] • Wyoming County Health Department Interim PUBLIC HEALTH DIRECTOR: Gregory Collins, DO PHONE: (585)786-8890 E-mail: [email protected] • The New York State Association of County Health Officials www.nysacho.org/Directory/directory.html Resources Department of Health and Human Services Pandemic Plan: www.cdc.gov/flu/pandemic/ New York State Department of Health: www.health.state.ny.us/diseases/communicable/influenza/pandemi c/index.htm Federal Pandemic Planning Resources Including Checklist: www.pandemicflu.gov The Occupational Health Disaster Expert Network ohden.sph.unc.edu