department of human services avian influenza and pandemic preparedness bruce mclaren communicable...

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

. o

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