Transcript Pertussis

Avian influenza and
pandemic preparedness
Bruce McLaren
Communicable Diseases Section
Phone
1300 651 160
24 hour page
1300 790 733
Department of Human Services
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
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
Biology
Type: Influenza A, B, (C)
Subtype (for Flu A): HxNy
Variants – site, year,
number
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
Avian influenza 1997-2006
Source: European Union
Avian influenza in humans
•
Source – European Union
Source: European Union
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
20
05
20 /1
05
20 /4
05
20 /7
05
20 /10
05
20 /13
05
20 /16
05
20 /19
05
20 /22
05
20 /25
05
20 /28
05
20 /31
05
20 /34
05
20 /37
05
20 /40
05
20 /43
05
20 /46
05
20 /49
05
/5
20 2
06
20 /2
06
/5
No. of Notifications per week
Summary of tested cases
Period 01/01/2005 to 01/02/2006 (Notification Date) - Influenza A
virus H5N1
5
4
3
2
1
0
Year / Week
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
Suspected avian influenza
• Risk factors
• Exposure
• Symptoms



Isolate – asap – before presentation!
Ring DHS re testing, transfer
Alert hospital and ambulance in advance
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)
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
Anti-viral medications
• Oseltamivir
– Treatment: 75 mg bd for 5 days
• within 48 hours of onset
• Reduce dose in severe renal failure (GFR <30
ml/min)
• Pregnancy and children <1 year – “no evidence”
• Nausea, vomiting, diarrhoea, hypersensitivity
• Effectiveness?
• Resistance?
Anti-viral medications
• Current situation:
– National stockpile: 4 million packs and
counting
– State “stockpile”
– Hospitals?
– Practices?
– Personal?
– Travellers and expatriates
Pandemic influenza
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
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)
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
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
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
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
Thanks
Bruce McLaren
Communicable Diseases Section
Phone
1300 651 160
Medical officer: 24 hour page
1300 790 733