Avian Influenza / Pandemic Influenza

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Avian Influenza / Pandemic Influenza

• Neyla Gargouri Darwaza, M.D.
• Surveillance Department
• Directorate of Disease Control
• Ministry of Health, Jordan

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Outline

• Influenza virus
• Avian influenza
• Influenza pandemic

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Influenza viruses

• Orthomyxoviruses
• Influenza virus   A, B, C  
• A birds, pigs, humans
• B C humans

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Influenza virus type A

• 16 different HA and 9 NA
• All subtypes found in birds
• Only H5 and H7 caused severe disease in birds
• Human disease caused by H1, H2, H3, N1, N2

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Influenza virus type A

• 2448 hours or hard non porous surfaces
• 812 hours on cloth, paper, tissue
• 5 min on hands
• 4 days in water 22ºC
• 30 days at 0ºC
• 30 min at 60ºC
• Inactivated by 70 alcohol, chlorine and
  disinfectants

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Genetic reassortment
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Pandemic influenza strain
Migratory water birds
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Understanding pandemic influenza

• Pandemics occur when a novel influenza strain
  emerges that has the following features
• readily transmitted between humans
• genetically unique (i.e., lack of preexisting
  immunity in the human population)
• increased virulence

Very widespread epidemic that affects a whole
region, a continent or the world.
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Previous pandemics
Death million Strain Flu Year
50 H1N1 Spanish 1918
2 H2N2 Asian 1957
1 H3N2 Hong Kong 1968
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Avian influenza H5N1

• Since mid-2003, H5N1 virus has caused the largest
  and most severe outbreaks in poultry on record.

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H5N1 among poultry or wild birds

• Cambodia
• China
• Croatia
• Indonesia
• Japan
• Kazakhstan
• Laos
• Malaysia

• Mongolia
• Romania
• Russia
• South Korea
• Turkey
• Thailand
• Ukraine
• Vietnam

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Global risk of avian influenza outbreaks
Category 1
Category 2
Category 3
Category 4
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Why is H5N1 very dangerous?

• Present in healthy waterfowl (e.g. ducks), shed
  in feces
• Very lethal to poultry and other animals
  including humans
• Big impact on trade and economics
• Crossed species barrier in 1997 in Hong Kong,
  caused 18 human cases 6 deaths

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Cumulative Number of Confirmed Human Cases of
Avian Influenza A/(H5N1) Reported to WHO
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Cumulative Number of Confirmed Human Cases of
Avian Influenza A/(H5N1) Reported to WHO
10 January 2006
Total number of cases includes number of
deaths.WHO reports only laboratory-confirmed
cases.
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Pandemic alert

• H5N1 currently lacks ability for efficient spread
  among humans
• But, continual H5N1 transmission in animals (and
  humans)
• increases viruses in environment and chances of
  humans being infected
• increases chances of mutations/reassortments to
  create pandemic virus

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Present situation
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Influenza pandemic

• Once a fully contagious virus emerges, its
  global spread is inevitable
• Given the speed and volume of international
  travel today, the disease could reach all
  continents in less than 3 months
• 2 waves of 6 weeks each

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Influenza pandemic

• Worldwide
• 30-50 human population
• 2 to 7.4 million deaths (conservative estimates,
  based on 1957 pandemic)
• In Jordan
• 1.75 million cases (AR 35)
• 10,000 deaths (CFR 0.6)

Attack rate Case fatality rate
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Influenza pandemic

• Recent studies1,2 suggest that 1918 H1N1 and H5N1
  are similar
• macrophage activities with high levels of
  cytokine production maybe a factor in the lung
  and other organ damage (cytokine storm)

1Kobasa et al Nature 2004431703 2Peiris et al
Lancet 2004363617
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If influenza pandemic takes place

• It will take several months before any vaccine
  becomes available
• Vaccines, antiviral agents and antibiotics will
  be in short supply unequally distributed
• Medical facilities will be overwhelmed
• It will affect essential community services
• It will cause social and political disruption and
  considerable economic losses

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Can a pandemic be prevented?

• Theory
• antiviral drugs can contain/eliminate pandemic
  virus
• soon after it develops ability to spread human to
  human
• WHO antiviral stockpiles for rapid deployment in
  initially affected countries

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Can a pandemic be prevented?

• Requirements
• good surveillance and rapid reporting
• rapid response teams
• stockpile of antiviral drugs, PPE, etc.

Personal protective equipment
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Can a pandemic be prevented?

• Challenges
• limited money
• limited staff and training
• limited planning, coordination, cooperation
  within government and with other countries

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Which antiviral?

• M2 protein inhibitor amantadine, rimantadine
• up to 30 resistance, one passage in cell culture
• not effective against H5N1
• Neuraminidase inhibitors oseltamivir,
  zanamivir
• multiple passages in cell culture required to
  produce resistance
• effective against H5N1
• Susceptibility or resistance to antivirals of the
  new strain of influenza virus???

Tamiflu, Relenza
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Suspected case of H5N1

• Symptoms
• Flu illness or respiratory illness
• AND
• History within 10 days of onset
• Travel to a country with documented H5N1 in
  poultry or humans, and/or
• Contact with poultry or domestic birds, or known
  or suspected patient with influenza H5N1

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How to reduce risk of infection?

• Thorough cooking of all foods from poultry,
  including eggs
• Avoiding contact with poultry and any surfaces
  that may have been contaminated by poultry or
  their feces/secretions

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How to reduce risk of infection?

• Frequent hand washing with soap water
• after touching birds
• after cooking food involving poultry or eggs
• Simple etiquette like covering nose mouth when
  sneezing coughing

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Conclusion

• The next pandemic is just a matter of time
• For the first time in human history we have a
  chance to prepare ourselves for a pandemic before
  it arrives
• Pray, plan and practice

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References

• http//www.who.int/csr/disease/avian_influenza/en/
  index.html
• http//www.cdc.gov/flu/avian/outbreaks/asia.htm

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Contact

• MOH/ Disease Control
• Tel [phone]
• Fax [phone]
• epijor_at_wanadoo.jo
• neylagd_at_yahoo.com

• MOH
• Tel [phone]
• MOA/ Hotline
• Tel [phone]