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LegionellosisLegionnaires’ Disease

Pontiac feverRare non pneumonic infections

Planktonic flagellatedvirulent transmissive

Nonmotile replicative phaseinside amoebae

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Biofilm in plumbing system

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Clin Micro Rev 2015;28:80 –118.

Environment

Human Host

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‘Broad Street”

NEJM N Engl J Med 1977; 297:1189-1197

Broad Street

• Community acquired and nosocomial • Mostly sporadic and occasionally outbreaks • Often severe and life threatening • Risk factors – males, smoking, older age, chronic

cardiovascular or respiratory disease, diabetes, alcohol misuse, cancer and immunosuppression

• Incubation: 2-10 days• Mortality: 8-12% (15-35% for nosocomial)

1977; 297:1197–1203

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Legionnaires’Disease is not an atypical pneumonia

The “atypical” organisms, so called because they are notdetectable on Gram stain or cultivatable on standard

bacteriologic media, include M. pneumoniae, C. pneumoniae, Legionella species, and respiratory viruses.

The Lancet Infectious Diseases 2009; 9:512-519

Clinical Presentation of LD

• Clinical and radiologic features are indistinguishable from other CAPs (i.e the features are not atypical)

• Clinical scoring systems are unreliable

• There are no distinguishing biomarkers

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Lancet Infectious Diseases 2013: 14;1011-1021

New Zealand 2013 : Incidence 35 / million per year

25

2728 17 21 24

1136 34 48

3743 38 32 45 35

4830 55 42 47 71

165

93

130

5

10

15

20

25

30

0

100

200

300

400

500

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

2015

Rate

per

mill

ion

popu

latio

n

No

. o

f ca

ses

Legionella Noifications by Year 1991 - 2015*

ACT NSW NT QLD SA

TAS VIC WA Rate

Melbourne Aquarium (n=125)Cooling towersMJA 2004; 180: 566–572

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CDI 2013; 37: E380

50.5%

48.6%

Legionella NNDS System, 2011

Lp/Ll 0 > = = < < > <

Communicable Diseases Intelligence 2013; 37; No4 E313

Notified cases Australia 2011

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Communicable Diseases Intelligence 2013; 37; No4 E313

Prevalence of LD among patients with pneumonia

• Adults with CAP worldwide– Typically 1-10%, mean ~5 %

• Australia - ACAPS - 3.4% (CID 2008;46:1513-1521)

• Adults with CAP Christchurch NZ during spring/ summer ~ 19%

• Children with CAP – Very uncommon

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Legionnaires Disease is more than just about outbreaks and cooling towers

1981; 94: 739-740 Isolation of L.longbeachae sg1 from potting mixes. T W Steele et al AEM 1990; 56:49-53

Does using potting mix make you sick? Resultsfrom a Legionella longbeachae case-control

study in SA Epi & Inf 2007; 135:34-39

Legionellosis Notification Rates - NZ • One third to one half of cases

come from Canterbury ( incidence > 3 times the national average)

• In Christchurch it is the most commonly identified cause of pneumonia for about half the year

• Has a seasonal peak in activity in spring/summer – more predictable than influenza

• ~ 85% of cases are due to Legionella longbeachae

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22 to 92 cases (x4) 1 in 20 positive 1 in 9 positive peak season (Nov – Jan)Mostly L.longbeachae

Distribution of cycle threshold (Ct) values for polymerase chain reaction–positive

specimens

Association between Ct and culture positivity Correlation - bacterial load and disease severityCt values lower for ICU admissions; non survival Decreased with increasing CURB-65 score

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PCR is the diagnostic method of choice for Legionnaires’ Disease

J. Clin. Microbiol. 2013;51:348-351

Antigen Detection Antibody Detection PCR

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Culture

Culture• Sensitivity 10-80%

• Buffered charcoal yeast extract (BCYE) + α ketoglutarate +

cysteine ± antibiotics

• Slower to grow – plates held 7 days

• Pretreat – acid or heat

• Specifically requested

• Fewer than 50% produce sputum

• Rejection criteria should not be applied – often non purulent

• Legionella - does not activate the alarm of blood cultures systems

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No. Year Sex/Age

Hosp Site Host Organism LUA Serology Outcome

1 2005 M/62.1 C SputumCAP:Psoriatic arthritis, mtx

L.pneumophila ndneg (single sample)

Deceased

2 2009 M/62.2 F BALCAP:SLE pred, mycophenylate

L. longbeachae ndneg (2 days apart)

Deceased

3 2010 M/58.8 A BW/BALCAP: CLL immunosuppressed

L. longbeachae nd neg (no SC over 6m)

Survived

4 2011 F/80.8 E LungCAP: Lung abscess; smoker

L. longbeachae nd Ll: 4096 Survived

5 2011 M/73.7 B BALHAP: refractory myelodysplasia;AML

L.pneumophila POSneg (single sample)

Deceased

6 2012 M/73.9 D BAL CAP: Dalby L. longbeachae NEG SC Ll 8192 (8d)

Deceased

7 2013 F/46.1 B BW/Sputum HAP: Relapsed AML L.pneumophila POSneg (no SC over 8w)

Survived +

8 2013 M/66.9 BPleural

F/SputumHAP: Cardiac amyloid L.pneumophila POS neg Deceased

9 2013 M/80.3 C WristRA, mtx; multiple sc nodules

L.sainthelensi nd nd Survived

10 2014 M/55.6 A SputumHAP/CAP?: Supraglottic SCC; Crohns azothioprine

L.pneumophila POS neg Survived

11 2014 M/66.4 A BW HAP: CLL L.pneumophila ndneg (no SC over 8w)

Survived +

Culture Positives SNP 2005 – 2015*

Legionella Urinary Antigen

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Legionella Urinary Antigen• Only detects L.pneumophila serogroup 1• Sensitivity: 70-80%• Specificity: approaching 100%• May be negative during first 1-3 days of illness• Quick - < 4 hours • Useful in those who do not produce sputum • Immunosuppressed patients can excrete Ag

for > 60 days (>300d)

MJA 2007;187:36-39

Legionella Urinary Antigen • EIA

– Binax Now sg1 – Biorad– IVD Research

• ICT – Binax Now sg1 – Oxoid Xpect

• PCR – Life River

• FIA • Quidel Corporation

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Legionella Urinary Antigen

0 0 13

0

5 2

0

0100200300400500600700800900

2008 2009 2010 2011 2012 2013 2014 2015

No.

of T

ests

LUA negative LUA positive

11/2261 tests positive (0.5%)7 patients positive Peaked in 2013 Wesley Outbreak

Legionella Urinary Antigen

* LUA pos 2 months later

No. Year Sex/Age

Hosp Host Site Culture LUA PCR SerolOutco

me

1 2010 F/47.8 ACAP: Crohns Humira

ND ND POS ND Neg Survived

2 2011 F/39.9 C

CAP: Psoriatic arthritis on immunosuppression

ND ND POS ND SC: 2048 Survived

3 2011 M/73.7 BHAP: refractory myelodysplasia;AML

BAL L.pneumophila POS ND Neg Deceased

4 2013 M/66.9 BHAP: Cardiac amyloid

Pl Fluid, Sputum

L.pneumophila POS ND Neg Deceased

5 2013 F/46.1* BHAP: Relapsed AML

Sputum L.pneumophila POS ND Neg Survived +

6 2013 M/61.9 D CAP: Unknown ND Negative POS POS SC: 512 Survived

7 2014 M/55.6 C

HAP/CAP?: Supraglottic SCC; Crohns azothioprine

Sputum L.pneumophila POS ND Neg Survived

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Serology

• Indirect immunofluoresence (IFA)• Subjective • Low titre positives • Cut-off for significance• 20-30% don’t seroconvert • Seroconversion 2-10 weeks • Cross reactivity – especially pooled antigen

– Absorption of sera with E.coli O13:K92:H4 • Range of antigens

– L. pneumophila sg1; sg1 – 14; sg1 – 6; sg7 – 14 – L.longbeachae sg1 sg2; L.bozemanni; L.micdadei

Wilkinson HW JCM 1979;10(5):685-9

Titre 2008 2009 2010 2011 2012 2013 2014 2015 Total % Total <128 12823 14207 14962 19130 16891 18076 17038 3135 116262 99.11128 106 150 115 141 124 65 31 9 741 0.63256 34 38 40 29 37 15 12 2 207 0.18512 18 11 6 9 11 8 0 2 65 0.06

1024 2 2 2 4 11 1 3 25 0.022048 0 2 2 4 0.00total 12983 14408 15125 19315 17076 18165 17084 3148 117304 100

Serology ALL SNP : Legionella pneumophilia sg1

Serology 2008 – 2015*

• L.pneumophila sg1 IFA • 117 304 tests; 105 719 patients

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Serology 2008 – 2015*

• L.longbeachae IFA • 117 304 tests; 105 719 patients

Titre 2008 2009 2010 2011 2012 2013 2014 2015 Total % Total <128 12263 13257 14081 18041 15433 16768 16270 2914 109027 92.9128 423 621 621 752 907 850 450 126 4750 4.0256 193 343 279 364 468 348 252 60 2307 2.0512 71 128 100 102 166 125 62 30 784 0.7

1024 24 34 30 32 56 37 29 9 251 0.22048 5 14 5 17 39 25 10 7 122 0.14096 4 10 7 7 3 7 6 2 46 0.08192 1 2 4 5 5 17 0.0total 12983 14408 15125 19315 17076 18165 17084 3148 117304 100

Serology ALL SNP : Legionella longbeacheae

Nucleic Acid Detection (e.g. PCR)

• Detects Legionella DNA• High sensitivity and specificity• Faster TAT than culture• Detects all species and serogroups• Costs and technical expertise no

longer a barrier for some laboratories

• Commercial NAATs now available e.g AusDiagnostics

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Any Sputum will do

• Sputum - preferred sample for PCR testing

• Quality measures do not apply • Induced sputums should be collected

from patients who cannot expectorate• Collecting induced sputum increases

case detection by about 36%

Eur Respir J 2014; 43: 644-6

Which patients with pneumonia should be tested for Legionnaires’ Disease?

• British Thoracic Society – LUA; Legionella culture – all patients with high severity pneumonia– Other patients with specific risk factors– All patients with CAP during outbreaks

• NICE (National Institute for Health and Care Excellence – LUA– moderate-or high severity CAP

• IDSA Guidelines – LUA, Culture if LUA positive– severe CAP; ICU admission, failure of outpatient antibiotic

treatment, active alcohol abuse, travel within the past 2 weeks, pleural effusion

–

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National Legionnaires’ Disease Case Finding (LegiNZ)

• Canterbury Approach

• Sputum samples tested for Legionella by PCR if there is any indication that the patient has pneumonia– Clinical information:

‘pneumonia” “consolidation” CAP

– Immunocompromised– LUA has been ordered– PCR specifically requested

• 1 Year study• To better understand

national epidemiology• To inform regional testing

and treatment protocols

Chief Health Officers Report

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Wesley Outbreak• Not in cooling towers

• Present in water in patient rooms - shower head & basins

• 15 of 85 (17.6%) of hospital water outlets cultured L. pneumophilaserotype 1 on initial survey

P1 2013

P2 2013P3 2011

Bartley PB et al Science Translational Medicine (submitted)

Wesley Response • No new admissions• Alternative hygiene measures

(bottled water, no showering) • Scalding of the WDS - 60C 10

minutes • Disinfection of WDS - alkaline

detergent (pH = 10.0) containing 10 mg/L free chlorine

• In-line chlorinator systems • Intensive monitoring - L.

pneumophila in water specimens

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2011 patient

2013 outbreak patient

2013 outbreak patient

2013 hot water isolate

Reference strains and non related isolates

Point Prevalence Study Public and Private Hospitals and RACF s

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CID Advance Access March 18, 2015No safe level of legionella colonisation

sites that could serve as a trigger point 30% previously suggested Wesley 17.6% at time of outbreak

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Travel associated LD

http://ecdc.europa.eu/en/publications/Publications/legionnaires-disease-surveillance-2012.pdf

Travel associated LD

http://ecdc.europa.eu/en/activities/surveillance/ELDSNet/Documents/1003_Travelassociated_Legionnaires_disease_2007.pdf

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Travel Associated LD

Key messages• Ubiquitous environmental organism• Not an atypical pneumonia• LD is more than just outbreaks, cooling

towers and potable water• PCR is the diagnostic method of choice• Non pneumophila disease:underdiagnosed• An ideal approach is to respond to local

epidemiology - however we need to first define the local epidemiology

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Acknowledgements

• Prof David Murdoch Christchurch • Australasian Society for Infectious Diseases

(ASID) 2015

typing

• Monoclonal antibody methods • restriction endonuclease analysis (REA)

ribotyping, • amplified fragment length polymorphism

(AFLP), • pulsed field gel electrophoresis (PFGE),

restriction fragment length polymorphism (RFLP),

• arbitrarily primed PCR7

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Wesley Outbreak

• Not in cooling towers • Present in patients

water - shower head & basin in patient’s room