department of human services avian influenza and pandemic preparedness bruce mclaren communicable...
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Department of Human Services
Avian influenza and Avian influenza and pandemic preparednesspandemic preparedness
Bruce McLarenCommunicable Diseases Section
Phone 1300 651 160
24 hour page 1300 790 733
• Avian influenza in birds
• Avian influenza in people
• DHS response to suspected cases
• Preparing for a pandemic in GP
• Overview of state/national plans
AimsAims
BiologyBiology
• 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
Type: Influenza A, B, (C)
Subtype (for Flu A): HxNy
Variants – site, year, number
BiologyBiology
HistoryHistory
Antigenic shift - Pandemics1918 - H1N1: 20-50 million deaths,
- approximately 2.5% mortality1957 - H2N21968 - 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 1997-2006Avian influenza 1997-2006
Source: European Union
•
Avian influenza in humansAvian influenza in humans
Source – European Union
Source: European Union
Avian influenza – DHS and Avian influenza – DHS and VictoriaVictoria
• 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 2005Tested cases: 13 since June 2005
Summary of tested casesSummary of tested cases
Period 01/01/2005 to 01/02/2006 (Notification Date) - Influenza A virus H5N1
0
1
2
3
4
5
Year / Week
No
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f N
oti
ficati
on
s p
er
week
Main features of tested casesMain 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 influenzaSuspected avian influenza
• Risk factors
• Exposure
• Symptoms
Isolate – asap – before presentation! Ring DHS re testing, transfer Alert hospital and ambulance in advance
Avian influenza –challenges Avian influenza –challenges in clinical practicein 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 medicationsAnti 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 medicationsAnti-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 medicationsAnti-viral medications
• Current situation:– National stockpile: 4 million packs and
counting– State “stockpile”– Hospitals?– Practices?– Personal?– Travellers and expatriates
Pandemic influenzaPandemic influenza
Preparing for a pandemic in Preparing for a pandemic in clinical practiceclinical 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 Preparing for a pandemic in clinical practiceclinical practice
• Immunisation of staff and high risk patients:– Current season influenza– Pneumococcal– Also for staff: MMR, ADT (boostrix -
pertussis)
Victorian and national Victorian and national pandemic plans: overviewpandemic 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 Victorian and national pandemic plans: overviewpandemic 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 Victorian and national pandemic plans: overviewpandemic 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 issuesBig 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
ThanksThanks
Bruce McLaren
Communicable Diseases Section
Phone 1300 651 160
Medical officer: 24 hour page 1300 790 733