Legionnaire’s Disease

HPA Surveillance & Outbreak Management

Rebecca Ingham

Health Protection Practitioner

West Yorkshire Health Protection Unit

The West Yorkshire HPU

West Yorkshire HPU:

5 CCDC’s (Consultant in Communicable Disease Control):

All CCDC’s are Dr’s in our Unit

Patch work – 1 CCDC to each patch

Duty CCDC - on daily basis

9 Health Protection Specialists:

8 HP Nurses + 1 HP Practitioner

Patch work – 2 HPS to each patch

Duty Professional – approx 1 or 2 days/ week

Surveillance team

PA support/ Administration Team

Trainees

Specialist Registrars (medic trained) & Specialist Trainees (non medic)/ FY2’s – Junior Dr’s

Legionella pneumophilia

• Ubiquitous: Aquatic: lakes and streams

• 46 species including L. pneumophilia (serogroup 1 causes most LD)

• Spread through aerosols

• Cooling towers, spas, shower heads, taps, humidifiers

• No person-to-person transmission

Clinical features

• Legionnaires’ disease: Incubation Period 2-10 days

Non specific flu like illness: fever, malaise, myalgia, headache, dry cough, anorexia often with diarrhoea and confusion

• Difficult to differentiate clinically from other atypical pneumonias

• Become ill quickly

• Complications:

resp failure, pericarditis, acute renal failure

• Treatment:

Erythromycin

• 5-15% mortality

• Pontiac fever: self limiting, Incubation Period 5-66hrs

Microbiological Investigation

• Culture: need special media

• Antibody detection: takes 3-6 weeks to rise to diagnostic levels

• Serogroup 1 urinary antigen: early diagnosis – fast and dirty testing of urine

• Usual to also get sputum or other respiratory samples (bronchial washings) for testing

• Genotyping available to support epidemiological investigations

i.e. human and env samples ‘fingerprint’ the same

• Environmental sampling to investigate suspected sources. Routine sampling not worthwhile

Epidemiology

• Incidence ?? Over 200 cases a year in the UK

• 70% in Males

• 90% in the over 30’s

• Travel associated accounts for about 50% of cases

Spain, Turkey, France, Italy, Greece

• 15% associated with outbreaks

• 2% hospital acquired

• Risk factors:

Age, smoking, lung and kidney disease, immunosuppression, alcohol

• Incidence appears to be rising, probably due to better awareness and testing

Year Total Cases Male CasesFemale Cases Deaths

Travel Associated

(Abroad & UK)

1997 226 165 61 28 114

1998 227 162 65 25 115

1999 200 150 50 28 91

2000 180 143 37 25 101

2001 182 142 40 26 100

2002 387 256 131 33 154

2003 314 238 76 35 174

2004 318 239 79 38 173

2005 355 271 83 30 179

2006 551 433 118 53 213

2007 442 328 114 53 199

2008# 359 281 78 34 152

Legionella cases Eng and Wales

0

20

40

60

80

100

120

140

160

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Month

Num

ber

of C

ases

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008#

Surveillance: Why?

• See trends: descriptive epidemiology, at risk populations – age, travel

• Detect outbreaks

• New infections: seasonal flu virus, pandemic virus

• Implement interventions to prevent spread of disease

• Monitor effectiveness of interventions

Dissemination of Surveillance Data

• Health Protection Report and HPA website

• European Legionnaires’ disease Surveillance Network (ELDSNet )

• European Centre for Disease Prevention and Control (ECDC)

• World Health Organisation (WHO)

Investigation of a Case

• Confirm case: Test validated at CfI

• Notifiable in Eng&Wales (since 2010)

• Risk factor history for previous 2 weeks

– Travel, place of work, hospital acquired?

• Other cases? (diagnosed, undiagnosed?)

• Inform LA H&S and HSE

• LA holds a database of cooling towers (is it up to date?) Check out sampling records

Surveillance Data Set:

• Patients demographics:

Age/ DoB/ Gender/ Home & Work Address/ Occupation

• Clinical History:

Onset/ Relevant med history/ Hospital admission/ Outcome

• Exposure history:

? hospital acquired

Community acquired (known exposure to cooling towers, whirlpool spas, showers)

Travel associated Country (s) visited, dates of stay, name & address of accommodation, room number, tour operator, use

of showers, spa pools

Household acquired - Use of household water system during incubation period, in absence of other exposures

Clusters, Outbreaks & Travel Associated Clusters

• Cluster

• Outbreak

• Travel Associated Cluster

Strength of evidence for outbreaks

• High

• Low

Outbreaks

• Active case finding

• Detailed analysis of movements

• Mapping

• Identify potential sources: inspections and detailed look at records

• Hospital acquired: check all sources

• Engineer’s advice

• Typing results

Legionella

Prevention and Control

• Health and Safety

– Employers should identify, assess and manage risks

– Cooling towers notified and maintained

– Testing and addition of biocides to limit growth

• Reporting of cases: locally and nationally

• Investigation of cases

• Increasing awareness

– Professionals: thinks of Legionella and if you find it report it

– Employers aware of risks and duties

– Public beware of the risks

Managing Outbreaks Requires All of us Working Together

How to reach us:

West Yorkshire HPU

6th floor South EastQuarry HouseQuarry HillLEEDS LS2 7UE

Telephone:

0113 386 0300

Duty desk: option 1

Email:

westyorksdutypro@hpa.org.uk

rebecca.ingham@hpa.org.uk

1st April 2013:

rebecca.ingham@phe.gov.uk

NB soon to be Public Health England

HPA website:

www.hpa.org.uk

1st April 2013

www.phe.gov.uk