Point of Care multiplexed molecular amplification and visual detection for HIV-1 adn beta-actin ...

20 Pages·2013·1.8 MB·English

by  Information Services

Point-of-care multiplexed molecular
amplification and visual detection for HIV-
1 and beta-actin without electricity
Dr. Jennifer Osborn,
Technical Program
Associate, Co-PI

Paul LaBarre,
Sr. Technical Officer, lead PI
Photo: Lisa Stroux/PATH
Problem: Lack of Appropriate Diagnostic Tests
Decentralized Low-Resource Laboratory
Centralized PCR
Laboratory
http://www.science.leidenuniv.nl/index.php/ibl/dna_markerpoint/view_inside
Photo: PATH
Page 2 4/8/2013
Point-of-care Testing in Low-resource Settings
Types of tests: Test settings Test users:

Hospital
• Hospital staff,
• RDT, molecular smears
lab tech

Peripheral
• RDT, PCR, ELISA, • Lab tech
Lab
microscopy

Clinic or Health
• RDT, • Clinical staff
Post
handheld instruments

• Minimally trained
Community
• RDT
health worker

• RDT Home
• Lay person

Pag e 3 4/8/2013
Molecular Diagnostics Technology Requirements
WHO
Polymerase Chain
Decentralized Low-Resource
Diagnostic Ideal POC Test
Reaction
Laboratory Criteria
Centralized PCR
Laboratory High cost Affordable Low cost
Highly sensitive Sensitive Highly sensitive
Highly specific Specific Highly specific
Technically trained Minimal user steps
User friendly
users required required
Rapid &
Days to months Minutes to hours
robust
Power and equipment Equipment No power required, no
required free complex equipment
Deliverable to
http://www.science.leidenuniv.nl/index.php/ibl/dna_markerpoint/vie
Not portable, Highly portable, dried
w_inside
developing
refrigeration required reagents
Photo: PATH
countries

Point-of-care molecular diagnostics could reduce the disease burden
•
Page 4 4/8/2013
Early Infant Diagnosis and Linkage to Care is Critical
370,000 new HIV infections from mother-to-child
•
transmission (UNICEF, 2008)
EID improves health
•
outcomes
CHER trial in South Africa:
•
76% reduction in
•
morbidity
75% reduction in
•
mortality

Photo: March of Dimes
Challenges with Current Tests
:
Available tests
•
rapid diagnostic tests (RDTs)
•
PCR for infant testing with dried blood spots
•

~60% of infants are lost to follow-up
•
Only 6-15% of HIV-exposed infants accessed testing
•
(WHO,
2009)

Maternal antibody interference Centralized laboratories

Photo: PATH

Photo: CDC
Defining Use Cases and Target Product Profiles
(TPPs)

Exploratory
Stakeholder
Interviews
Technical
Use Case(s) TPP(s)
Specifications
User Needs
Assessments
Alpha Prototype
Design Iterations
NIH RO1
Target product profile process helps to ensure
•
technologies will meeting existing needs
PATH’s Approach: A Non-Instrumented Nucleic
Acid (NINA) Diagnostic Platform
Exothermic Isothermal Nucleic Point-of-Care NINA
Heat A cid Amplification Heater Device
PCR Tubes
www.ontech.com PCM
Curtis et al. J. Med. Virol.
Photo: PATH
81:966–972 (2009)
MgFe/H2O
Reaction
Isothermal amplification simplifies the power
•
requirements for amplification
Page 8 4/8/2013
Benefits of NINA Compared to PCR Testing
Gold WHO NINA
Standard: Diagnostic Heater +
PCR Criteria LFD
Centralized PCR High cost Affordable Low cost Point-of-Care
Laboratory NINA Heater
Highly sensitive Sensitive Sensitive
Highly specific Specific Specific
Technically
Minimal User
trained users User friendly
Steps
required
Days to months Rapid & robust ~60-90 minutes
Power and No power or
Equipment
complex complex
free
equipment equipment
Photo: PATH
Not portable, Deliverable to
Photo: Highly portable,
http://www.science.leidenuniv.nl/index.php/ibl/dna_markerp refrigeration developing
oint/view_inside dried reagents
required countries
The NINA heater is designed for nucleic acid detection in low-
resource settings for improved acute and infant HIV diagnosis.
Page 9 4/8/2013
NINA Kit concept
User-friendly Operation of the NINA Heater