Avian Influenza Avian Influenza A

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					Avian Influenza A (H5N1)
       “Bird Flu”
      November 18, 2005

     Charles W. Mackett III, MD FAAFP
             Executive Vice Chair
       Department of Family Medicine
    University of Pittsburgh Medical Center
• 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

                                                             T ranmi ssi on                 al so   d

                                                              Direct bird to human
                                                             to p eop le.

                                                              transmission is also common
                                      Domestic birds

         Natural avian                 Pandemic
        influenza cycle               disease cycle

Shore                     Waterfowl                        Mammals
birds                                                  (primarily swine)

      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

                 Bird flu by the numbers
    Human cases since date of onset (12/26/03)     125

    Human deaths                                   64

    Suspected human-to-human transmissions         2

    Number of countries affected (since Dec 04)    12

    Est. international airline passengers yearly   1.6B

    Types of potential antivirals for bird flu     2
    Known bird flu types                           15

    Bird flu that can be fatal to humans           1

    Best case global deaths in pandemic            2-7M
    Worst case potential global deaths             40-100M

*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
  –   1st 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)
•   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
• 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.
•   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' 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


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