Challenges and advances in laboratory methods for the detection of Legionella pneumophila in on-premise testing

Transcription

1 Challenges and advances in labratry methds fr the detectin f Leginella pneumphila in n-premise testing

2 Why shuld yu be cncerned with Leginella? The # f cases f leginellsis have increased 286% ver the past 14 years 8,000 t 18,000 peple cntract leginellsis in the U.S. each year (estimated) 5-15% f the knwn cases f leginellsis are fatal 2 Cpyright 2017 IDEXX Labratries

3 Clinical causes f leginellsis causative agents Culture-cnfirmed patient cases f L. pneumphila Year n % ECDC Leginnaires' disease in Eurpe, Surveillance Reprt Reprted culture-cnfirmed cases f Leginnaires' disease and Leginella islates by species, EU/EEA, Cpyright 2017 IDEXX Labratries

4 Outbreaks: ptable vs. nnptable water 4 Cpyright 2017 IDEXX Labratries

5 Leginella is ubiquitus, but it can be managed Up t 70% f all building water systems are cntaminated with Leginella Ptable and nnptable waters are ptential surces f Leginella cntaminatin Building wners & managers are respnsible fr cntrlling it Leginnaires Disease is a grwing public health issue that is preventable 5 Cpyright 2017 IDEXX Labratries

6 Leginellsis is preventable with tls and guidance: ASHRAE Standard CDC Guidelines Versin Cpyright 2017 IDEXX Labratries

7 Hw d yu reduce health and legal risks? Test regularly t cnfirm risk management practices are wrking prperly Perfrm crrective actins if needed and retest t cnfirm actins have reduced the risk Keep recrds f yur test results and crrective measures! 7 Cpyright 2017 IDEXX Labratries

8 Testing fr Leginella The Gld Standard is culture methd 8 Cpyright 2017 IDEXX Labratries

9 Leginella Traditinal Culture Methds Examples Different methds = Different results 9 Cpyright 2017 IDEXX Labratries

10 But which culture methd? Many prtcl ptins, each cntributing t Measurement Uncertainty Cncentratin Membrane filtratin Centrifugatin Pretreatments (t reduce the backgrund) Acid Heat Media Frmulatins - GVPC, PVC, MWY, DGVP, CCVC, etc. Manufacturers Fllw up and cnfirmatin methds Plate media Sertype - latex agglutinatin Direct flurescence antibdy micrscpy Sequencing 10 Cpyright 2017 IDEXX Labratries

11 Cntributrs t Measurement Uncertainty Cncentratin Membrane filtratin Lss f target rganism due t vacuum pressure Membrane variability can impact target capture and recvery Impaired grwth f target due t reduced cntact with media Centrifugatin Lss f target rganism during the decant Pretreatments (t reduce the backgrund) Acid and/r Heat Lss f target rganisms that are sensitive t treatment Nn-target rganisms resistant t treatment and impact target Media Frmulatins - GVPC, PVC, MWY, DGVP, CCVC, etc. Lss f target rganisms that are sensitive t frmulatin Nn-target rganisms resistant t frmulatin and impact target Manufacturers Prducts vary by manufacturer and lt which can negatively impact target recvery and nn-target suppressin 11 Cpyright 2017 IDEXX Labratries

12 Cntributrs t Measurement Uncertainty Results Interpretatin Analyst Analyst experience level Methd Subjectivity f clny differentiatin Interference f nn-target grwth 12 Cpyright 2017 IDEXX Labratries

13 Results Interpretatin, 7 day results Plates cuntable Sme nn-leginella interference, plates difficult t read and cunt Cmplete nn-leginella interference, plates unreadable 13 Cpyright 2017 IDEXX Labratries

14 Results Interpretatin, 7 day results One sample was plated 4 times at 3 dilutins The impact f the nn-target interference can vary wildly 1. Sample A, 1:2 dilutin 2. Sample A, 1:4 dilutin 3. Sample A, 1:6 dilutin 14 Cpyright 2017 IDEXX Labratries

15 Cumulative impact f Measurement Uncertainty The varius cntributrs f measurement uncertainty we have discussed will have a cumulative impact Results Interpretatin Media Manufacturer Pretreatment Methd Media Frmulatin Cncentratin Methd Ttal Measurement Uncertainty 15 Cpyright 2017 IDEXX Labratries

16 Rutine testing The best decisins cme frm data that is: Accurate Highly reprducible s trending is accurate, n matter wh is prcessing yur sample Specific fr disease causing agent 16 Cpyright 2017 IDEXX Labratries

17 Legilert, the next generatin culture test Ideal fr rutine mnitring and cmpliance Detects all sergrups f Leginella pneumphila Highly specific, little backgrund interference Simple t use, clr reactin similar t Clilert Reprducible and repeatable Can be used fr ptable and nnptable matrices Matrix-specific prtcls Uses mst prbable number (MPN) t quantify, which is the same quantificatin as CFU Cunts f up t 2,272 per test, much higher than petri plates Incubates fr 7 days t yield a cnfirmed result 17 Cpyright 2017 IDEXX Labratries

18 Legilert Unique 100 ml Quanti-Tray device 6 large wells (verflw) 90 small wells (reslutin) Cunts L. pneumphila; frm MPN/ Quanti-Tray Blister pack reagent Reactin with L. pneumphila Negative Sample 18 Cpyright 2017 IDEXX Labratries

19 Legilert Legilert Quanti-Tray/Legilert Quanti-Tray/Legilert Insert IDEXX Labratries, Inc. All rights reserved. Quanti-Tray Sealer PLUS

20 Legilert ISO Methd Validatin Perfrmance Validatin f Legilert ISO/TR 13843:2000(E) Water Quality Guidance n validatin f micrbilgical methds Metric Value Sensitivity 98% Specificity > 99% False psitive rate < 0.01% False negative rate 4.20% Efficiency > 99% Repeatability < 0.01 Reprducibility < IDEXX Labratries, Inc. All rights reserved.

21 Legilert Studies cmpleted and in prgress Multiple trials and validatins by independent labs with ptable and nnptable samples Cmpleted t date Studies in the US, Canada and Germany 10 independent labratries 3,570 matched samples analyzed All results published, under review r being written up fr publicatin in peer review jurnals In prgress Studies in Italy, UK, Australia, Singapre, US, and Germany Planning phase Studies in France, Prtugal and Spain IDEXX Labratries, Inc. All rights reserved.

22 22 Cpyright 2017 IDEXX Labratries Questins