Rapid diagnostics in general practice - what can help now?

Dr Derren Ready

Independent review of Antimicrobial Resistance Jim O’Neill

Diagnostics are critical to the appropriate use of antimicrobials

Step change in the way technology is incorporated into the decision making process

Rapid point of care diagnostics enabling a precise, timely diagnosis

Decision support approach to drive change in prescribing

Key requirements of diagnostics in AMR

Speed

Specificity Sensitivity

Cost

•  Quality is dependent on many factors:

•  National defined criteria

•  Test itself •  Interpretation & use •  Tester competence

•  Value balance: cost effectiveness, timeliness and quality

•  Need the evidence base to underpin decisions

•  Surveillance!

Quality and

evidence

Point of Care Test (POCT) Need

Training

Will / desire

Cost

Inexpensive, rapid, can be undertaken proximal to patient

Multiple tests now available:

•  Influenza A/B / RSV

•  GAS / GBS

•  MRSA/SA

•  Cdiff1

•  HIV

New diagnostic approaches

New diagnostic technologies fall into two main areas:

Indirect: (identifying markers of infection)

- identifying patients in whom antibiotics may be appropriate

- response patterns

Direct: (identifying infectious diseases)

- identifying pathogens & resistance

- assessing susceptibility

Meningitis

Testing panel

Blood culture

Gastrointestinal

Respiratory

•  Antibiotic resistance genes •  Hypervirulence genes •  Common & unusual bacteria and viruses

Respiratory STI

Cancer Markers Cardiac risk

Respiratory

Sepsis

Under validation

Gastrointestinal

Blood culture CNS

Currently available

7 POCT testing

Group A pharyngitis

Group A Streptococci - bacterial pharyngitis, which require antibiotic therapy. 96 participants consisted of 44 women (46%) and 52 men (54%); children aged 3-14 years constituted 46% of the patients. S. pyogenes were cultured from 43 of 96 pharyngeal swabs. Almost half of all positive samples (47%, n = 20) were collected from children aged 3 to 14 years. The PPV of the test was 83% and its NPV was 92%. Using quick tests to detect GAS antigens appears a good alternative to conventional microbial diagnosis of strep throat, as it enables making a diagnosis and deciding on treatment plan in one appointment.

TaqMan®ArrayCards

1 to 8 samples

1 µL reaction volume

TaqMan® Assays pre-spotted

48 wells per channel

1 2 3 4 5 6 7 8

384 wells (1µL reaction volume)

TaqMan®ArrayCards-workflow

1 2 3 4 5 6 7 8

LoadtheTAC

Centrifuga2on Sealing

• 20ulofnucleicacidextract• 26ulofTaqman®Fastvirus1-step• 58ulofRnasefreewater • 2x2min300g/1200rpm

Trimtheportstrip Amplifica2on Dataanalysis

• 50/5min(RT)95°C/20sec• 95°C/1sec60°C/20secX45cycles• 53minrunOme • Approx.10min

CostefficientIndividual Tests Price

Adenovirus £49 Candida albicans £49 Candida spp £23 Chlamydia trachomatis £57 CMV £21 Enterovirus £56 Escherichia coli £41 HSV £23 H. influenzae £193 L. monocytogenes £111 M. genitalium £98 Mec_A £30 M. hominis & Ureaplasma £161 N. meningitidis £36 Parechovirus £80 S. aureus £30 S. pyogenes £100 S. agalactiae £100 S. epidermidis £29 Staph CoNS £29 S. pneumoniae £100 T. pallidum & VZV £111

£1,527 £50

Biomarkers of infection POCT

CRP

Procalcitonin< 10mins Diazyme PCT POC Test

Lactate StatStrip® Connectivity and StatStrip Xpress Point-of-Care Lactate Analyzers

13 seconds, 0.6 µL whole blood

Multi-analyte:

Complete Blood count and CRP counts on <0.018mL in 4 minutes

Horiba haematology

Other makes are available!

Metagenomics

POCT genomics

Genomics PHG Foundation: Genomics and the management of antimicrobial resistance: current successes and future challenges The targeted use of genomics presents a valuable opportunity to support and enhance the ability of the health services to minimise ineffective use of antibiotics and antivirals, to combat the spread of resistance through improved infection control, and to ensure that these vital therapies continue to be effective in the years to come. Already in use for surveillance and outbreak analysis… Increasing use within the system nationally

H14314073002 H14314073202 H14332051408

H14332051608 ENV H14314072802 H14314072902 H14314073108

H110860291 H110860288 H110860290 H110860289

H110160676 H110540155 H110260244

H111660292 H112020673 H112100161

MGAS5005

5

A

B

C

D

emm 1.0

emm 1.0

emm 1.52

emm 1.53

ulcerfootswab

ulcerfootswab

bloodculture

chair

throatswab

bloodculture

legswab

throatswab

throatswab

throatswab

throatswab

bloodculture

swab

eyeswab

bloodculture

bloodculture

sputum

Any questions?