Diagnostic testing for tuberculosis

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Diagnostic testing for tuberculosis
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3 - 9 months
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The slow road to microscopy diagnosis of TB
Implement molecular test with sensitivity similar
to culture
AFB/ml
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Abbreviating delay through better sensitivity or
better access
Implement dipstick with sensitivity equal to
microscopy
10,000,000 AFB/ml
Implement molecular test with sensitivity similar
to culture
AFB/ml
Where delay contributes greatest to morbidity,
mortality, transmission
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Where is the point of care for TB and how do you
get to it?
Reference center District hospital Microscopy
center Health post
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Referral for 3.8b people in 22 HBC
325
Reference center District hospital Microscopy
center Health post
1500
27,000
270,000
1,52m?
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Strength of health system
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Major Markets
Rest of World

• Simple one-step testing in 15 minutes
• Accurate, quantitative readout
• Simultaneous results from multiple markers
• Portable, low maintenance instrument
• Built-in quality control

• Complex, slow tasks
• Inaccurate, qualitative readout
• Single marker, single disease
• Heavy, high maintenance instruments
• Absent quality control

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FIND a public engine for diagnostic development
FINDs focus
Upstream
Downstream
Market access and
distribution
Discovery and research
Development
Evaluation
Demonstration
Liaise with funders, pharmaceutical and biotech
companies, research institutions, academia
Liaise with funders, multi-lateral agencies,
NGOs,health ministries, and agencies like GDF
and GFATM
Create network of public and private partners to
create effective tests and demonstrate their
success
Development Facilitate, co-fund, co-develop
Evaluation Regulatory- quality lab field trials
Demonstration Large-scale projects measuring
feasibility and impact on disease control
programs
Proof of principle
Product in box
Efficacy Data
Effectiveness Data
Policy
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Making US standard accessible in DEC

• Price negotiations on MGIT
• Licensing agreement for MPT64
• Development for lower cost version
• Large demonstration projects (gt100,000 pts)
• Customer support plan

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Steps in Hain test for molecular MDR screening
with PCR and line probe hybridization
Process specimen, extract DNA, amplify DNA
targets with PCR
Hybridize amplified DNA to oligonucleotide probes
on strips
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Geneva, Switzerland - 2007
17 y.o. male admitted to hospital with cough and
fever
AFB microscopy positive patient placed in
isolation pending drug susceptibility testing
Conventional DST results fully susceptible
18th birthday passed in isolation
weeks
0
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5
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1
2
6
3
7
9
8
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Evolution of TB diagnostics in the public sector
Fundamental diagnostic 1882
Fundamental diagnostic 2009
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Integrated NAAT for TB/Rif
Automated sample preparation Amplification and
detection lt 2 h
Xpert TM MTB/Rif

• Workflow
• fully automated, with 1-step external sample
  prep.
• time-to-result lt 2 h (walk away test)
• throughput up to 1-48 tests / run
• no bio-safety cabinet
• closed system (no contamination risk)

• A technology platform for
• TB Rif resistance
• TB Quinolone resistance
• Potential for HIV viral load

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Xpert MTB/Rif FIND Evaluation studies
Rigorous performance evaluation at 5 sites
(gt1500 TB suspects) Included 2 sites with high
HIV prevalence (80) 2 with high MDR prevalence
(gt30)
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Xpert MTB/Rif FIND evaluation studies
Sensitivity for in S/C 100, in S-/C 91
High accuracy for Rif detection Sequencing data
for discrepant results suggest Xpert correct
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Simple, manual NAAT

• Closed system
• Isothermal
• Rapid
• Multiprimer
• Visible readout

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TB LAMP Procedure

• Single instrument
• From 32 to 7 steps
• From 15 to 3 plastics

85?, 5 min
Mixing
Sputum
One drop
Dried reagent
LAMP reation 67? 40 min
Calcein fluorescence
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Spiked sputum samples
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Decentralization of molecular diagnostics
1st generation MDR
Less complexity, more robustness
2nd generation automated MDR
1st generation manual detection
2nd generation manual detection
POC test
Xpert
LPA
LAMP
2008 2010
2011
2015
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Serodiagnosis of TB
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Sensitivity of selected antigens at gt95
specificity level compared to healthy controls
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Whole proteome screening of M. tuberculosis for
diagnostic antigens
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Mtb Antigen Detection Another needle in the
haystack?

• Collaborations
• Existing Assays Chemogen, Inverness, Biomed, J
  Mitra, Lionex, SMI / TBDiaDirect, Standard, ANDA
• Biomarkers Forsythe, Harvard / Beth Israel, SSI,
  Proteome Systems, TAUNS, Cellzome, St. Georges
  Hospital, Genovac, Cornell, NYU, MPI / GC-6, KIT,
  Scensive, EMBO
• Technology SBRI, CibiTest, Nanogen, LRE Medical
  Inverness, DKFZ, Singulex, Chimera, deTect,
  Roche, Luminex, ProteomeBinders, BD, Biomerieux,