Simplification, cost-reduction strategies and examples from the
fieldTeri Roberts
Diagnostics Advisor Medecins Sans Frontieres, Access Campaign
7th International AIDS Conference 2 July 2013
Virological monitoring detects treatment failure earlier than clinico-immunological monitoring
How viral load testing fits into the package of care to ensure people stay undetectable
Early treatment
Routine viral load
Adherence support
Community-based &
self-managed therapy
Drop routine CD4 monitoring for virally suppressed ART treated PLWHA and rather use routine VL monitoring to trigger the need for CD4 testing (is CD4 over 200 cells/ul?)
Viremic patients can re-suppress following an adherence intervention
The importance of preserving first line, affordable, robust, one-pill-a-day regimens
Implementation is done in support of, and in collaboration with, the Ministries of Health and reference laboratories
SAMBA
CAVIDI
BIOMERIEUX
BIOCENTRIC
• G. Patten et al. Poster TUPDD0106 (Oral abstract session: The point of point of care (Tuesday))
• Youth and adolescents have been identified as a particularly vulnerable group, at greater risk of loss from both pre-ART and ART care.
• MSF supported clinic in Khayelitsha, Cape Town, South Africa: implemented POC CD4-testing at a clinic dedicated to youth aged 12 to 25 years.
• POC CD4 testing significantly improved assessment for ART eligibility, ensuring that most youth were made aware of their treatment needs on the day of HIV diagnosis.
Does point-of-care (POC) CD4 testing reduce losses from care between HIV diagnosis, assessment for ART eligibility and ART initiation among HIV-positive youth in Khayelitsha, South Africa?
Group A (Before) Group B (After)
HIV Testing
Blood sample drawn for CD4 counting
WHO Staging*
ART preparation counselling sessions
ART Initiation
CD4 Result
ART eligibility assessed
Visit 1
Visit 2
Visit 3
Visit 4
Visit 5
Visit 6
HIV Testing
Blood sample drawn for CD4 counting
WHO Staging
ART preparation counselling session
ART Initiation
CD4 Result
ART eligibility assessed
Visit 1
Visit 2
Visit 3
Visit 4
Visit 544% 50%
34 days 28 days
P=0.6
Point-of-care versus laboratory-based tests for viral load testing
Regional-level laboratory tests will
use dried blood spot samples that can use
finger or heel prick blood
Diagnostic accuracy of DBS using the COBAS Ampliprep/COBAS TaqMan HIV-1 v2.0 (CAP/CTM)
• NMRL, Harare, Zimbabwe in collaboration with MSF• Sekesai Mtapuri-Zinyowera (WEPE610 - Poster Exhibition on Wednesday)• 118 finger prick DBS, venous blood DBS and plasma specimens from ART patients attending
two rural OI clinics in Buhera and Tsholotsho districts and one urban OI clinic in Harare• good sensitivity of DBS compared to HIV-1 RNA plasma but very low specificity, which
translated in a higher rate of false positive results with DBS at lower VLs (<3.5log)
COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 TestDried Fluid Spot Procedure RUO
Sample Collection
±70 μL of capillary and EDTA blood (air dry min. 3h)
detach and transfer1 spot (Ø 12 mm)
560C, 10 min, 1000 rpm+1000 μL SPEX
S-input tube
Controls
Fully automated nucleic acid extraction and amplification/detection
Pre-extraction
Pooling methods, in combination with the use of fingerprick DBS as a sample type for VL testing, can importantly reduce costs
while maintaining accuracy
Efficiency expressed as cost savings:• Example of Thyolo District
– Population: 620,000– HIV prevalence: 14,5%– # VL tests needed/year: 23,000– Price per VL test: $24
• Total cost/year = 23,000 x $24 = $552,000– Efficiency at 1,000 cps/mL = 28,6% => $157,800 saved– Efficiency at 5,000 cps/mL = 51,4% => $283,700 saved
Sample 1500 µL
100 µL
Pool 500 µL
Viral load testing
100 µL100 µL
100 µL100 µL
Sample 2500 µL
Sample 3500 µL
Sample 4 500 µL
Sample 5 500 µL
What to do with pooled results?1. Pooled VL result < threshold => no further testing 2. Pooled VL result > threshold => further testing
MSF has previously validated the use of fingerprick DBS on the bioMerieux NucliSENS EasyQ HIV-1 platform, which is RNA-specific
Reports: www.msfaccess.org/reports
2012
IAS poster TUPDD0102 and Oral abstract session: The point of point of care (Tuesday)
2013