Preparing for an Influenza Pandemic in Westminster Health and Community Services Overview and Scrutiny Committee 9 Oct 2006 Dr Margaret Guy Director of.

Preparing for an Influenza Pandemic

in Westminster

Health and Community Services Health and Community Services Overview and Scrutiny Committee Overview and Scrutiny Committee

9 Oct 20069 Oct 2006

Dr Margaret GuyDr Margaret Guy

Director of Public HealthDirector of Public Health

What is a flu pandemic?

Flu pandemics occur when a new influenza virus emerges which is able to:

infect people; infect people;

spread readily from person to person;spread readily from person to person;

cause illness in high proportion of people infected; andcause illness in high proportion of people infected; and

spread widely.spread widely.

Influenza virus

An RNA virus An RNA virus

Three types: A, B, and CThree types: A, B, and C

A & B are major human A & B are major human pathogens: give rise to pathogens: give rise to ‘normal’ epidemics in ‘normal’ epidemics in winterwinter

Only influenza A virus is Only influenza A virus is recognised as having the recognised as having the potential to cause a potential to cause a pandemicpandemic

Influenza A subtypes

H antigen - 16 different subtypesH antigen - 16 different subtypes N antigen - 9 different subtypes N antigen - 9 different subtypes

Both antigens change over time, H more than NBoth antigens change over time, H more than N

DriftDrift Minor continuous changes in same subtypeMinor continuous changes in same subtypeResults in epidemics - almost every Results in epidemics - almost every

winterwinter ShiftShift Major abrupt change in subtypeMajor abrupt change in subtype

May result in pandemic as little/no May result in pandemic as little/no immunityimmunity

1920 1940 1960 1980 2000

Circulating influenza strains in humans and pandemics in 20th Century

H1N1 H1N1

H2N2

H3N2

1918: “Spanish Flu”

40-50 million deaths

1957: “Asian Flu”

1 million deaths

1968: “Hong Kong Flu”

1 million deaths

Domestic birdsMigratory water birds

• Hong Kong 1997, H5N1

• Hong Kong and China 1999, H9N2

• Netherlands 2003, H7N7

• Hong Kong 2003, H5N1

• Vietnam and Thailand, 2004 H5N1

Transmission of Avian Flu to humans

Emergence of pandemic strains

Migratory water birds

Avian Flu - H5N1

First isolated from terns in 1961 in S. AfricaFirst isolated from terns in 1961 in S. Africa Outbreaks in 8 countries in SE Asia during late Outbreaks in 8 countries in SE Asia during late

2003 and early 20042003 and early 2004 From late June 2004 new deadly outbreaks From late June 2004 new deadly outbreaks

reported in Cambodia, China, Indonesia, reported in Cambodia, China, Indonesia, Malaysia Thailand Vietnam and TurkeyMalaysia Thailand Vietnam and Turkey

These are ongoingThese are ongoing

Mortality during the pandemic of 1918-19

3 epidemic waves in fairly close succession

March 1918, Sept 1918, Feb 1919

Up to 40 million deaths world-wide, including…

198,000 excess civilian deaths in Britain

500,000 excess civilian deaths in USA

A/H1N1 – Spanish influenza

Mortality in other 20th century pandemics

1957-1958 (A/H2N2) – Asian flu

USA, 80,000 excess deaths

Worldwide: Estimated 1.0 million deaths

1968-1970 (A/H3N2) – Hong Kong flu

UK: 30,000 excess deaths (c/f 26,000 in 1989-90)

Worldwide: Estimated 0.8 – 1.0 million deaths

Peoplewho consult

their GP

People infected withsymptoms

People infected without symptoms

191825%

50%

195725-33%

1968

25-33%

Morbidity associated with pandemic influenza

April 2005

WHO Influenza Pandemic Phases Inter-pandemic PeriodInter-pandemic Period   Phase 1 Phase 1 No new influenza virus subtypes detected in humans. No new influenza virus subtypes detected in humans.    Phase 2 Phase 2 No new influenza virus subtypes detected in humans, but No new influenza virus subtypes detected in humans, but

circulating animal influenza virus subtype poses substantial risk of human circulating animal influenza virus subtype poses substantial risk of human disease.disease.

Pandemic Alert PeriodPandemic Alert PeriodPhase 3 Phase 3 Human infection with new subtype but no new human-to-human Human infection with new subtype but no new human-to-human spread, or, at most, rare instances of spread to close contact.spread, or, at most, rare instances of spread to close contact.Phase 4 Phase 4 Small cluster(s) with limited human-to-human transmission but Small cluster(s) with limited human-to-human transmission but spread highly localised, suggesting virus not well adapted to humansspread highly localised, suggesting virus not well adapted to humansPhase 5 Phase 5 Large cluster(s) but human-to-human spread still localised, Large cluster(s) but human-to-human spread still localised, suggesting virus becoming increasingly better adapted to humans, but may suggesting virus becoming increasingly better adapted to humans, but may not yet be fully transmissible (substantial pandemic risk).not yet be fully transmissible (substantial pandemic risk).

Pandemic PeriodPandemic PeriodPhase 6 Phase 6 Pandemic phase: increased and sustained transmission in general Pandemic phase: increased and sustained transmission in general population; second and further waves likely 3-9 months after previous wave population; second and further waves likely 3-9 months after previous wave has subsided has subsided

Post Pandemic PeriodPost Pandemic PeriodReturn to inter-pandemic periodReturn to inter-pandemic period

Implications for the UK

If there are cases in the UK during the pre-pandemic If there are cases in the UK during the pre-pandemic period, the international phases apply. period, the international phases apply.

   Once a pandemic has been declared (Once a pandemic has been declared (Phase 6Phase 6), a four ), a four

point UK-specific alert mechanism has been point UK-specific alert mechanism has been developed (consistent with alert levels used in other developed (consistent with alert levels used in other UK infectious disease response plans):UK infectious disease response plans):

Alert level 1: Alert level 1: Cases outside the UK Cases outside the UK

Alert level 2: Alert level 2: New virus isolated in the UKNew virus isolated in the UK

Alert level 3: Alert level 3: Outbreak(s) in the UKOutbreak(s) in the UK

Alert level 4: Alert level 4: Widespread activity across the UK.Widespread activity across the UK.

Influenza – transmission of infectionInfluenza – transmission of infection

Incubation periodIncubation period1-3 days1-3 days

Virus sheddingVirus shedding 24 hours before symptoms and up to 9 days after onset 24 hours before symptoms and up to 9 days after onset

of symptomsof symptomsOnly considered to be infective when symptomaticOnly considered to be infective when symptomatic

TransmissionTransmissionRespiratory secretions - airborne droplet spread by Respiratory secretions - airborne droplet spread by coughing, sneezing or contaminated handscoughing, sneezing or contaminated hands

Reducing the impact of a Flu Pandemic

Immunisation against influenza Immunisation against influenza

Pneumococcal immunisation Pneumococcal immunisation

Measures to reduce the transmission of influenzaMeasures to reduce the transmission of influenza

Restriction of travel or mass gatherings Restriction of travel or mass gatherings Action by individuals Action by individuals Action by health and care staff Action by health and care staff Action to reduce spread in residential facilities Action to reduce spread in residential facilities

Antiviral drugs Antiviral drugs

Planning for a Flu Pandemic

NationalNationalUK National Influenza Pandemic Committee (UKNIPC)National Director of Pandemic Influenza PreparednessNational Director of Pandemic Influenza Preparedness

LondonLondonLondon Health Pandemic Flu Steering Group London Health Pandemic Flu Steering Group London Pandemic Flu Coordinator London Pandemic Flu Coordinator

WestminsterWestminsterWestminster Influenza Pandemic CommitteeWestminster Influenza Pandemic Committee WestminsterWestminster Influenza Pandemic Coordinator Influenza Pandemic Coordinator

Local estimates of service demand (17-week pandemic wave) Per week* **Per week* ** Total**Total**

New influenza casesNew influenza cases 460 rising to 7590460 rising to 7590

(920 rising to 15180)(920 rising to 15180)

5612056120

(112240)(112240)

GP consultationsGP consultations 92 rising to 151692 rising to 1516

(184 rising to 3032)(184 rising to 3032)

1126111261

(22522)(22522)

A&E presentationsA&E presentations 23 rising to 37923 rising to 379

(46 rising to 759)(46 rising to 759)

28062806

(5612)(5612)

Hospital admissionsHospital admissions 2 rising to 442 rising to 44

(4 rising to 88)(4 rising to 88)

363363

(726)(726)

Excess deaths assuming a Excess deaths assuming a 0.37% 0.37% case fatality rate case fatality rate

2 rising to 282 rising to 28

(4 rising to 56)(4 rising to 56)

209209

(418)(418)

Excess deaths assuming a Excess deaths assuming a 2.5% 2.5% case fatality rate case fatality rate

12 rising to 19012 rising to 190

(23 rising to 380)(23 rising to 380)

14031403

(2806)(2806)

*The highest figures are given for week 9 within a 17 week pandemic wave period** Estimated 25% attack rate with 50% attack rate given in parenthesis

Service demand during worst 8 weeks of pandemic (weeks 5-12)

Per week* **Per week* ** Total**Total**

New influenza casesNew influenza cases 3220 rising to 75903220 rising to 7590

(6440 rising to 15180)(6440 rising to 15180)

4508045080

(90160)(90160)

GP consultationsGP consultations 653 rising to 1516653 rising to 1516

(1306 rising to 3032)(1306 rising to 3032)

90649064

(18128)(18128)

A&E presentationsA&E presentations 161 rising to 380161 rising to 380

(322 rising to 759)(322 rising to 759)

22542254

(4508)(4508)

Hospital admissionsHospital admissions 16 rising to 4416 rising to 44

(32 rising to 88)(32 rising to 88)

276276

(552)(552)

Excess deaths assuming a Excess deaths assuming a 0.37% 0.37% case fatality rate case fatality rate

12 rising to 2812 rising to 28

(24 rising to 56)(24 rising to 56)

168168

(336)(336)

Excess deaths assuming a Excess deaths assuming a 2.5% 2.5% case fatality rate case fatality rate

81 rising to 19081 rising to 190

(161 rising to 3797)(161 rising to 3797)

11271127

(2254)(2254)

**Estimated 25% attack rate with 50% attack rate given in parenthesis

Planning for a Flu Pandemic in Westminster

35%

1,127

4001,432

Total Deaths

215

110358

1 2 3 4 5 6 7 8

68 113 169 214 214 169 113 68

24 40 60 76 76 60 40 24

86 143 215 272 272 215 143 86

Hosp Adm. / Week

Most Likely ScenarioMinimum ScenarioMaximum Scenario

Pandemic Influenza Impact / Attack Rate

Most Likely Scenario

Minimum Scenario Maximum Scenario

Total Hospital Admissions

Most Likely Scenario

Minimum Scenario Maximum Scenario

Distribution of admissions: By week, 8 week outbreak 35% attack rate

0

50

100

150

200

250

300

1 2 3 4 5 6 7 8Weeks of outbreak

Wee

kly

adm

issi

on

s

Maximum

MinimumMost Likely

Planning for a Flu Pandemic in Westminster

Total Hospital Admissions (most likely)

1,127

Total Deaths (most likely)

215

Distribution of admissions: By day, 8 week outbreak 35% attack rate

05

1015202530354045

1 8 15 22 29 36 43 50Days of outbreak

Da

ily #

of

ad

mis

sio

ns

Most likely Minimum scenario Maximum scenario

Workstreams

Westminster-wide workWestminster-wide work Joint work between all health service Joint work between all health service

providersproviders Joint work with Westminster City CouncilJoint work with Westminster City Council

Westminster-wide work Overarching Westminster Influenza Pandemic Overarching Westminster Influenza Pandemic

Contingency PlanContingency Plan Command and control structuresCommand and control structures Agreeing responsibility for local actions Agreeing responsibility for local actions

+ development of action cards+ development of action cards Business continuity Business continuity Communications Strategy Communications Strategy Staff trainingStaff training Supplies and logisticsSupplies and logistics Monitoring arrangementsMonitoring arrangements BudgetsBudgets

Joint work between health service providers Arrangements for administering antivirals and vaccine Arrangements for administering antivirals and vaccine

– Flu centres– Flu centres Supporting self careSupporting self care Triage of those who seek adviceTriage of those who seek advice Mounting the Primary Care ResponseMounting the Primary Care Response Mounting the Secondary ResponseMounting the Secondary Response Maintaining services for people who do not have Maintaining services for people who do not have

influenzainfluenza Role of private hospitals and nursing homes Role of private hospitals and nursing homes Hospice care provision Hospice care provision Infection control measuresInfection control measures Ensuring business continuity plans are complementaryEnsuring business continuity plans are complementary

Joint work with Westminster City Council

Flu centres – identification of suitable sitesFlu centres – identification of suitable sites Mortuaries – including liaison with CoronerMortuaries – including liaison with Coroner Joint work with Social Services in relation to Joint work with Social Services in relation to

the provision of services to people in receipt of the provision of services to people in receipt of PCT services and social servicesPCT services and social services

Ensuring business continuity plans are Ensuring business continuity plans are complementarycomplementary

Provision of antivirals/vaccine for WCC Provision of antivirals/vaccine for WCC essential staffessential staff