Presentation on theme: "Avian Influenza A (H5N1) “Bird Flu” TRCPA November 18, 2005 Charles W. Mackett III, MD FAAFP Executive Vice Chair Department of Family Medicine University."— Presentation transcript:
Avian Influenza A (H5N1) “Bird Flu” TRCPA November 18, 2005 Charles W. Mackett III, MD FAAFP Executive Vice Chair Department of Family Medicine University of Pittsburgh Medical Center
Etiology Viral disease Avian Influenza (HPAI) –H5 and H7 – highly pathogenic –Human case fatality estimated to be as high has 50%, but not definitely known
Cycle of Avian Influenza viruses in animals & humans Shore birds Pandemic disease cycle Natural avian influenza cycle Mammals (primarily swine) Waterfowl Domestic birds Humans Direct bird to human transmission is also common
How is bird flu monitored? WHO and CDC maintain regional labs that test both bird and human specimens Periodic updates are provided The lab surveillance permits implementation of control measures if needed Vaccine trials are underway for the H5N1 strain, but are in early phases
WHO Pandemic Alert Phase Plan
Map of current outbreak FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
Bird flu by the numbers Human cases since date of onset (12/26/03)125 Human deaths64 Suspected human-to-human transmissions2 Number of countries affected (since Dec 04)12 Est. international airline passengers yearly1.6B Types of potential antivirals for bird flu2 Known bird flu types15 Bird flu that can be fatal to humans1 Best case global deaths in pandemic2-7M Worst case potential global deaths40-100M *Source: World Health Organization
First case of bird flu in the U.S.
Previous avian flu in the U.S. Delaware (H7N2) –Reported February 6, 2003 –12,000 chickens –Low pathogenicity Texas (H5N2) –Reported February 23, 2004 –1 st such case in U.S. in 20 years –7,000 chickens –Highly pathogenic No H5N1
Human H5N1 Incubation: 3-5 days Few URI symptoms Severe viral pneumonia picture –Fever –Lymphopenia –Pulmonary infiltrates –Hypoxia Diarrhea (50%) Time to death: 10 days (mean)
Transmission Respiratory droplets vs. aerosol Hand to hand Fomites Viral shedding starts 24 hours before clinical illness and lasts 5-7 days
Prerequisites for a pandemic Novel virus with no immunity Able to cause significant disease in humans Efficient human to human transmission –Re-assort during co-infection with H3N2 –Evolve in a human by spontaneous mutation
Common pandemic features Herald wave (warning): up-tick in mortality at end of prior year Increased mortality Mortality shift to younger ages Multiple waves of increased mortality for several years
Potential for influenza pandemics All influenza viruses can mutate Avian flu can cause illness in humans Little to no herd immunity to avian strains among humans If avian viruses acquire human genes –Facilitate efficient person-to-person transmission H5N1 of particular concern No one can predict when a pandemic might occur
How is bird flu in humans treated? The H5N1 virus currently infecting birds in Asia that has caused human illness and death is resistant to amantadine and rimantadine Neurominidase inhibitors –oseltamavir (Tamiflu) –zanamavir (Relenza) inhaled, not stocked in house –Resistance can develop Additional studies are needed to prove the effectiveness of these medicines.
Defenses Vaccination Prophylaxis Rapid diagnosis Treatment Infection control –Respiratory etiquette –Hand washing –Disinfection –Droplet precautions in hospitals
CDC recommendations Enhanced surveillance in the U.S. of H5N1. Travelers to countries with known outbreaks of influenza A (H5N1) should avoid: –Poultry farms –Contact with animals in live food markets –Surfaces that appear to be contaminated with feces from poultry or other animals. CDC does not recommend any travel restrictions to affected countries at this time. For more information, visit Travelers' HealthTravelers' Health
CDC pandemic preparation Providing leadership and working with: National Pandemic Influenza Preparedness and Response Task Force, created in May 2005 by the Secretary of the U.S. Department of Health and Human Services Association of Public Health Laboratories on training workshops for state laboratories Council of State and Territorial Epidemiologists and others to help states with their pandemic planning efforts Department of Defense and the Veterans Administration on antiviral stockpile issues World Health Organization (WHO) and Vietnamese Ministry of Health to investigate influenza H5N1 in Vietnam and provide help in laboratory diagnostics and training
CDC pandemic preparation Offering laboratory testing for H5N1 viruses Funding a $5.5 million initiative to improve influenza surveillance in Asia Holding or taking part in training sessions to improve local capacities to conduct surveillance for possible H5N1 human cases Developing and distributing reagents kits to detect the currently circulating influenza A H5N1 viruses Working together with WHO and the National Institutes of Health (NIH) on safety testing of vaccine seed candidates and to develop additional vaccine virus seed candidates for influenza A (H5N1) and other subtypes of influenza A virus
UPMC Avian Flu Task Force Under the Direction of Loren Roth, MD, MPH Sr. V.P., Quality Care & Chief Medical Officer Comprised of experts in : –infectious disease-virology –critical care-epidemiology –emergency management-emergency medicine –pathology-mental health –medical laboratory-medical logistics –human resources-public affairs –corporate security-Center for Biosecurity of UPMC; The Task Force works closely in cooperation with the Allegheny County Health Department and Region 13 emergency management in facilitating and guiding UPMC’s preparations Preparation for a possible pandemic has been ongoing since early this year
Thank You! Many thanks to : UPMC Avian Flu Task Force Center for Biosecurity of UPMC Questions?