Pasientnær testing av infeksjonssykdommer - NITO€¦ · Pasientnær testing av infeksjonssykdommer André Ingebretsen Avdeling for mikrobiologi og Avdeling for smittevern ... •Xpert

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Pasientnær testing av infeksjonssykdommer

André IngebretsenAvdeling for mikrobiologi og Avdeling

for smittevernOslo universitetssykehus

Avdeling for smittevern, OUS• Kompetansesenter for smittevern i Helse Sør-Øst

– MLST på K.pneumoniae, E.faecium, C.albicans

– spa-typing på S.aureus

– MLVA på C.difficile

– PCR ribotyping på C.difficile

– RAPD PCR på G- mikroorgansimer– PFGE – WGS pipeline– Vannanalyser i helseinstitusjoner (Legionella etc)– Under utvikling: HRM analyser

• Nasjonal kompetansetjeneste for dekontaminering• Nasjonal referanselab i medisinsk mikrobiologi –

Clostridium difficile

Automasjon innen mikrobiologi 2015 André Ingebretsen

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Hva gjør en test hurtig?Preanalyse

• Kunnskap• Transport• Åpningstider• Pasientnære labfasiliteter / instrumenter• Elektronisk rekvirering

I laboratoriet

•Kunnskap•Åpningstider

•Prioritering•Lablogistikk•Hurtig rapportering

•Telefon•Foreløpige svar

•Elektronisk svar

I klinikken

• Kunnskap• Elektroniske svar

• Rådgivende personell (mikrobiologer, smittevernspersonell, infeksjonsmedisinere, teknisk personell)


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Genomics & Proteomics i klinisk mikrobiologi


Differensiering av laboratoriet


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Pasientnære tester


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Pasientnære tester

• POC – ”point-of-care”

• Pasientnært - ingen transporttid.

• Enkel i bruk

• Billig?

• Hurtiganalyser

• Kvalitetssikring over web

• Bruk på desentraliserte steder


LUCAS (Lensless, Ultra-wide-field Cell monitoring Array platform based on Shadow imaging)

Pasientnære tester


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Pasientnære tester

• Immunokromatografisk test

• Detekterer antigener

• Differensierer P. falciparum fra andre

• Sensitivitet P.f: 99.7% - 53.9%

• Sensitivitet P.vivax: 93.5% - 6.2%

• Spesifisitet : 94.2% - 99.8 %

• Hjemmetesting?


Avlesning


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Molekylære hurtigtester


Niemz et al. Trends in biotech. 2011.5; 240-250

GeneXpert


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GeneXpert


Evaluation of GeneXpert® MRSA for rapid detection of Methicillin-Resistant Staphylococcus aureus (MRSA).

Safina Khan, Hanane Belmekki (Biomedical laboratory scientists), Gaute Syversen (MD. Consultant). Department of Microbiology, Division of Diagnostics and Intervention, Oslo University Hospital, Norway.

Introduction:MRSA is Staphylococcus aureus containing mecA or mecC gene, responsible for methicillin resistance. MRSA is highly contagious, and screening to prevent nosocomial transmission is important. Methods for phenotypic identification of MRSA take a long time. Xpert MRSA (Cepheid) is a rapid real time PCR for genotypic identification of MRSA. The purpose of this evaluation is to assess the clinical performance of Xpert MRSA compared with CHROMagar MRSA culture (reference method).

Materials and Methods:Specimens were collected from a selected group of patients in Oslo University Hospital, Ullevål from 21.07.2009 to 30.12.2011. This group included primarily persons at risk of importing MRSA from health care centers abroad and persons who had been exposed because of contact with a known MRSA case. Swabs in Copan venturi- and Copan Eswab transport medium from nose, throat, hands, perineum and wound sites were tested.

Xpert® MRSA assays:We used four types of kits i.e. •Xpert MRSA version 3.0 (21.07.2009 to 02.12.2009 and 11.01.2010 to 11.05.2010)•Xpert MRSA G3 version 6.0 (12.05.2010 to 30.12.2011)•Xpert MRSA/SA Nasal version 1.0 and Xpert MRSA/SA Nasal G3 version 1.0 (03.12.2009 to 10.01.2010). To save costs, throat, hands and perineum swabs were analysed together in a single cartridge.

Figure 1. Swab and elution reagent vials, Cartridge and GeneXpert real time PCR instrument (Cepheid).

Results:Table 1. All GeneXpert® MRSA test kit results.

Table 2. Xpert MRSA and Xpert MRSA G3 conclusive results compared to culture results.

The performance of the Xpert MRSA and Xpert MRSA G3 kits compared to culture is shown in Table 2. The sensitivity was 92.0%, the specificity 98.0%, positive predictive value 82.5% and negative predictive value 99.2%.Table 3. Xpert MRSA/SA Nasal and Xpert MRSA/SA Nasal G3 conclusive results compared to culture results.

The performance of the Xpert®MRSA /SA Nasal and Xpert®MRSA /SA Nasal G3 kits compared to culture is shown in Table 3. The sensitivity was 74.5%, the specificity 97.7%, positive predictive value 90.4% and negative predictive value 93.0%.Table 4. All Xpert MRSA kit results compared to culture results.

Data shown in Table 4 gives the following performance of the Xpert MRSA kits compared to CHROMagar MRSA culture as the gold standard: sensitivity: 90.0%, specificity: 98.0%, positive predictive value: 83.2% and negative predictive value: 98.9%.

Xpert® MRSA Xpert® MRSA G3 Xpert® MRSA /SA Nasal Xpert® MRSA /SA Nasal

G3

Total

Negative 1463 2676 177 11 4327

Positive 123 335 23 19 500

Invalid 28 166 12 0 206

Error 5 17 4 0 26

No result 0 1 0 0 1

Total 1619 3195 216 30 5060

Sum of invalid, error + no

result

33

(2.0%)

184 (5.7%) 16 (7.4%) 0 (0.0%) 233

(4.6%)

Culture positive Culture negative Total

Xpert pos 378 80 458

Xpert neg 33 4106 4139

Total 411 4186 4597


Xpert pos 416 (8.6%) 84 (1.7%) 500 (10.4%)

Xpert neg 46 (0.9%) 4281 (88.7%) 4327 (89.6%)

Total 462 (9.6%) 4365 (90.4%) 4827

Conclusion:Xpert MRSA kits are fast, easy to perform and can accommodate the urgent cases. The lower specificity and positive predictive value are probably caused by MSSA with SCCmec without functional MecA, and Xpert MRSA results need to be confirmed by culture. It is known that the SPA-types t230, t442, t688, t2958, t6667 are poorly detected by Xpert MRSA, but the negative predictive value is high in low prevalence settings. In our laboratory GeneXpert real time PCR is mainly used to define negative cases, and even if it is expensive, it is cost effective as a negative Xpert MRSA result allows treatment of the patients without prolonged isolation awaiting culture test results.


Xpert pos 38 4 42

Xpert neg 13 175 188

Total 51 179 230

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Genexpert MBT/Rif

(n=595) Sens Spec PPV NPV

Respiratory 97,1% 98,6% 95,7% 99,1%

Non-Resp 33,3% 99,7% 80,0% 97,3%

GX: 8 Rif-rest. Fenotypisk kun 5 Rif-rest.


IVD-godkjente kit 2014

Influenza

C.difficile

S.aureus

vanA/vanB

MRSA/SA

Enterovirus

Gruppe B streptokokker

B.anthracis

MTB/Rif

Norovirus


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Film array

• Luftveispanel

• Bioterror panel

• Blodkultur panel

• GI panel

• Meningitt/Encephalitt panel


Film array


Idaho technology Inc.

(Biomerieux)

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Film array

• Blodkulturtest– Polymikrobiell deteksjon

– Relativt få publikasjoner

– Liten database sammenlignet med MALDI

– 25 patogener + 4 res.gen• Sens/Spec = 91-95%

• Luftveistest– 20 targets virus/bakt

– Relativt få publikasjoner

– Sammenlignbart med andre PCR

– Sens/Spec = 87 -95%

Blaschke, AJ. et al. Diagn Microbiol Infect Dis. 2012 Dec;74(4):349-55.

Pardo, J. et.al. J Clin Microbiol. 2014 Jun;52(6):2262-4

Rand &Delano. Diagn Microbiol Infect Dis. 2014 Mar 22. pii: S0732-8893(14)00124-2

Piralla et al. Diagn Microbiol Infect Dis. 2014 Jun;79(2):183-6


PA Portrait analyzer


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UNIVERO system


UNYVERO system


Jamal et al. J Clin Microbiol. 2014 Apr 30

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Lab-on-a-chip

• Microfluidic flow

• Isolerer komponenter i en væskestrøm

• T/H-sensor

• Aktiv/passiv

• Diffusjon


PanNAT system (micronics)


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Lab-on-a-chip 2

• Q-POC instrument

• Microfluidic flow + PCR + Nanowire FET tech

• Ekstraksjon og amplifisering av DNA

• Rask – 15 min

• Under utviking

• Malaria, MDR TB, STI


Q-POC system


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Q-POC system


Q-POC system


https://youtu.be/izvT1PxP8jY

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Den perfekte pasientnære testen


Modell for fremtidig organisering

• Elektronisk overføring av svar

• Elektronisk mikrobiologisk validering/ vedlikehold

• Små POC laboratorier inkl. MIK, IMMI, MBK

• Tverrfaglig lab personell

Hovedlab

Kliniske avdelinger

Primær HT

Små sykehus

Satellitt-Labs

Hjem


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Oppsummert

• Hvor hurtig er hurtig?

• Hvem betaler?

• Hvem er ansvarlig for testene?

• Hvem ivaretar kvalitetssikring?

• Mange nye tester

• Lavprevalent/høy prevalent


Documents

Pasientnær testing av infeksjonssykdommer - NITO€¦ · Pasientnær testing av infeksjonssykdommer André Ingebretsen Avdeling for mikrobiologi og Avdeling for smittevern ... •Xpert