In Vitro Diagnostic Platforms for the Developing World

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David Kelso Oak Ridge April 20, 2012 In Vitro Diagnostic Platforms for the Developing World

Transcript of In Vitro Diagnostic Platforms for the Developing World

David Kelso Oak Ridge April 20, 2012

In Vitro Diagnostic Platforms for the

Developing World

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Center for Innovation in Global Health Technologies

Industry

Academia

Philanthropy

Key Contributions: • Technology, Manufacturing, Regulatory,

Distribution, Current Partners:

Key Contributions: • Project Coordination, New Technology, Market Research and

Product Development, Field Experience Current Partners: • McCormick School of Engineering – Center for Innovation in

Global Health Technology (CIGHT) • Kellogg School of Management – Global Health Initiative (GHI) • Feinberg School of Medicine

Key Contributions: • R&D Funding, Mission,

Field Experience Partners:

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Northwestern Global Health Foundation

¡  Researches markets ¡  Funds technology transfer ¡  Contracts with device manufacturers ¡  Conducts field evaluations ¡  Supports and services products

Non-profit distributor of medical devices in developing world

Need for point-of-care

early infant HIV diagnostic, EID

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¡  1.4 million infants were born to HIV-positive women in 2007 ¡  390 thousand infants infected ¡  If not diagnosed and started on antiretroviral therapy,

35% of infected infants will die by age 1 year, 52% by age 2

¡  2.8 million adjusted life years could be saved annually assuming 100% sensitivity and availability of ART

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National and Private Hospitals & Reference Lab, Research

Institute

Regional or Provincial Hospital

District Hospital /

Urban Hospitals

County Hospital

Outreach Programs

Rural Health Care Center or VCT

Level:

Testing sites in the developing world

Source: 2008 Kellogg field research

EID test volumes in Uganda

Tests per Day per Facility

% o

f all

test

s

Cum

ulat

ive

%

• Across health facilities, test volumes ranged from 1 to 14 tests per day

• Overall, health facilities had a median volume of 1 test per day (IQR:1, 2)

• 96.8% of all tests performed took place on days where the facility performed 5 tests or less

Uganda Daily Testing Analysis

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¡  Obtain plasma without centrifuge ¡  Disrupt immune complex ¡  Add liquids without pipets ¡  Detect pM concentrations of p24 antigen ¡  Turnaround time < 1 hr. ¡  Function in ambient temperatures > 40C ¡  Send results to central lab

Technical challenges

Plasma without centrifugation by filtration

Variation of plasma volume

Disrupt immune complex by heat shock

Effects of heat shock

¡  Disrupts antibody -antigen complex

¡  90-95 °C for 5 min required for high avidity patients

¡  p24 antigen refolds, epitopes of test antibodies intact

¡  Gel forms in specimens with high IgG levels

By SafeTech capillary By absorbent pad By unit dose dispenser

Transfer liquids without pipets

Detect p24 antigen by immunochromatographic assay

ICA components

•  Antibody coated carbon nanoparticles •  Biotinylated capture antibody •  SA on capture line •  Anti-mouse IgG on control line •  pM limit of detection

p24 antigen ICA clinical performance

¡  389 samples tested in NHLS lab in Cape Town South Africa ¡  24 (6.2%) were positive by PCR ¡  p24 antigen ICA detected 23 for

sensitivity of 95.8% (95% confidence limits: 79.8 – 99.3%) ¡  2 false positives for specificity of 99.4% (95% CI: 98.0 –

99.8%), ¡  Turnaround time 45 min.

p24 antigen correlation with viral load

¡  18 samples tested with viral loads 345 to 2 million ¡  All samples positive except the 3 with the lowest viral loads ¡  Lowest viral load detected was 6,580 copies/ml

Global temperature ranges

Timbuktu, Mali http://www.world66.com/africa/mali/timbuktu/lib/climate

-20

-10

0

10

20

30

40

J F M A M J J A S O N D

Lhasa, Tibet http://www.asia-planet.net/china/temperature2.htm

Function in temperatures > 40°C

•  Peltier heats and cools tube •  Reaction temperature 30 °C

Communicate with central lab

•  Cellular modem with SIM card •  Push buttons to enter P, N, I •  Results stored in flash memory •  Phones lab at pre-scheduled time •  Transmits results

Kenya  planned  communica2ons  network  

Roche CAP/CTM Analyzer(EID and Viral Load)

Online SQL database on Server rendered by PHP to any web browser

Health Facility: USSD/ SMS Query for test results

Health Facility: PCs accessing data over the Internet

PC software controlling the analyzer

Becton Dickenson FACSCalibur for CD4 testing

SYSMEX Hematology analyzer

Reference  Laboratories  

Health Facility: GSM Printers on GPRS or SMS

EMR Patient test results

p24 plans

¡  Transfer production to contract manufacturers ¡  Test in Mozambique & Malawi clinics 3rd quarter

FDA export certificate required ¡  Conduct studies in Zambia, Uganda, Kenya, Nigeria, India ¡  Develop test strip reader

Need for point-of-care HIV viral load monitor

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¡  34M people living with AIDS ¡  23M in sub-Saharan Africa ¡  15M in need of anti-retroviral therapy ¡  6.6M receiving ART

Need for point-of-care

TB diagnostic

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¡  8.8M new TB cases in 2010 ¡  22 high burden countries ¡ Multi-drug resistant, MDR ¡  Extensively drug-resistant XDR

¡  Viral load PCR detection limit HIV VL 50c/ml ¡  Viral load precision to monitor changes ¡  Obtain plasma without centrifugation ¡  TB culture detection limit 10 cfu/ml ¡  Safe handling of TB sputum specimens ¡ Workloads in large treatment clinics ¡  TB turnaround time < 1 hr ¡  HIV turnaround time < 2 hrs

NAT Technical Challenges

¡  Useful ¡  Affordable ¡  Appropriate ¡  Accurate ¡  Robust ¡  Reliable

Critical attributes