Avian influenza and pandemic preparedness

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Avian influenza and pandemic preparedness
Bruce McLaren Communicable Diseases
Section Phone [phone] hour page 1300
790 733
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Aims

• Avian influenza in birds
• Avian influenza in people
• DHS response to suspected cases
• Preparing for a pandemic in GP
• Overview of state/national plans

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Biology

• Influenza virus
• Changeable
• Mutation antigenic drift
• Reassortment antigenic shift
• Haemagglutinin binding to cells virulence
  factor
• Neuraminidase release of virus from cell
• Many species affected horses, felines, mink,
  seals
• Interspecies infection pigs, birds, humans

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Biology
Type Influenza A, B, (C) Subtype (for Flu A)
HxNy Variants site, year, number
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History

• Antigenic shift - Pandemics
• 1918 - H1N1 20-50 million deaths, -
  approximately 2.5 mortality
• 1957 - H2N2
• 1968 - H3N2
• Antigenic drift variable epidemics year to year
• eg 2005 A/New Caledonia/20/99 (H1N1)
  A/Wellington/1/2004 (H3N2)
• B/Shanghai/361/2002 or B/Jiangsu/10/2003

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Avian influenza 1997-2006
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(No Transcript)
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Source European Union
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Avian influenza in humans

Source European Union
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Source European Union
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Avian influenza DHS and Victoria

• Current picture Overseas phase 3
• human infection overseas with a new sub-type of
  influenza but no human to human spread or at most
  rare instances of spread to a close contact
• Testing at DHS
• Countries reporting avian influenza (bird or
  human)
• Plausible contact (animal, laboratory, patient)
• Notified cases 64 since June 2005
• Tested cases 13 since June 2005

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Summary of tested cases
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Main features of tested cases

• First presentation GP 10, hospital 3
• Hospitalised - 8
• Age range 25 80 years 9 Male 4 Female
• Countries visited HK 3, China 3,
• Thailand 3, Vietnam 2, Indonesia 1,
  Australia 1
• Occupation Lab technician x 1, Lab assistant x
  1, tourist x 11
• Outcome no isolate 5 influenza A (H3) 6
  influenza A (nonH5) 1 picornavirus 1

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Suspected avian influenza

• Risk factors
• Exposure
• Symptoms
• Isolate asap before presentation!
• Ring DHS re testing, transfer
• Alert hospital and ambulance in advance

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Avian influenza challenges in clinical practice

• Recognition exposure history plus compatible
  illness (plus timelines)
• Forewarning of presentation see at home if
  possible
• Unusual presentations diarrhoea and fever,
  encephalitis
• Countries without apparent avian influenza (eg
  Iraq)

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Anti viral medications

• M2 inhibitors eg amantadine (Flu A only)
• Current H5N1 is resistant
• Possible role in pandemic for treatment
• Neuraminidase inhibitors oseltamivir (tablet,
  syrup), zanamivir (oral inhalation)
• Prophylaxis Oseltamivir 75 mg daily up to 6
  weeks
• After contact begin asap, 10 days
• 50-70 effective

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Anti-viral medications

• Oseltamivir
• Treatment 75 mg bd for 5 days
• within 48 hours of onset
• Reduce dose in severe renal failure (GFR lt30
  ml/min)
• Pregnancy and children lt1 year no evidence
• Nausea, vomiting, diarrhoea, hypersensitivity
• Effectiveness?
• Resistance?

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Anti-viral medications

• Current situation
• National stockpile 4 million packs and counting
• State stockpile
• Hospitals?
• Practices?
• Personal?
• Travellers and expatriates

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Pandemic influenza
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Preparing for a pandemic in clinical practice

• Protect yourself and staff
• Waiting room posters
• Train receptionists
• PPE ON wash, mask, goggles, gown gloves
• OFF gloves, wash, goggles, gown, mask,
  wash
• Planning
• Absentees
• Appointments
• Separation
• Handling problems demand, aggression

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Preparing for a pandemic in clinical practice

• Immunisation of staff and high risk patients
• Current season influenza
• Pneumococcal
• Also for staff MMR, ADT (boostrix - pertussis)

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Victorian and national pandemic plans overview

• Stages actual pandemic will be phases 4 and 5
  (overseas) and 6 (Australia)
• Waves weeks or months apart
• Victoria first 6-8 weeks
• 2,000 10,000 deaths (usual avge. 700/week)
• - 6,000 25,000 admissions
• - 600,000 750,000 outpatients

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Victorian and national pandemic plans overview

• Strategy
• Preparedness
• Containment
• Maintenance of essential services
• Hospitals
• Designated hospitals (NPR and isolation)
• Dedicated wards
• Dedicated influenza hospitals
• Fever clinics

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Victorian and national pandemic plans overview

• Primary care
• Business as usual?
• Changed routines
• separation of clinics?
• Task force home visits?
• Fever clinics
• Rotation of staff six weekly?
• Divisions, AMA, practice managers

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Big pandemic issues

• Anti-virals
• Treatment priorities?
• Prophylaxis contacts
• Prophylaxis essential services
• Managed by Govt, dispensed by clinicians
• Vaccine
• Pre-preparation
• Effectiveness almost certainly 2 doses
• Timelines weeks to months to develop
• Rapid deployment

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Thanks

• Bruce McLaren
• Communicable Diseases Section
• Phone [phone]
• Medical officer 24 hour page 1300 790 733