Simplification, cost-reduction strategies and examples from the

field Teri Roberts

Diagnostics AdvisorMSF Access Campaign

Virological Monitoring Detects Treatment Failure Early On

Adapted from Bartlett et al. Lancet Infect Dis 2009

Across programmes: 2% of treated patients are on 2nd-line ARTIn South Africa (Khayelitsha), where routine virological monitoring is available: 12% on 2nd-line after 5 years

HIV Policy and Progress Indicators Across 16 CountriesCameroon CAR DRC Ethiopia Guinea India

VL for Tx failure

OPT OPT OPT NO OPT REQ

Routine VL OPT NO NO NO NO NO

Available LTD LTD LTD LTD LTD LTD

Kenya Lesotho Malawi Mozambique Myanmar

VL for Tx failure

OPT OPT REQ OPT OPT

Routine VL NO NO NO REQ NO

Available YES LTD LTD NO LTD

South Africa Swaziland Uganda Zambia Zimbabwe

VL for Tx failure

REQ OPT OPT OPT OPT

Routine VL REQ NO OPT OPT NO

Available YES LTD LTD LTD LTDLynch et al. Science 2012OPT: optional; REQ: required; LTD: limited

How to increase access to virological monitoring?

• Reduce complexity• Reduce price

– Market entry– Volume– Competition– Open and polyvalent platforms– Price transparency

• Field validate new and current tests (point of care and lab-based)• Perform operational research to define best adapted and most feasible

tests for different settings• Introduce viral load testing in a phased in approach

– Define testing frequency– Replace CD4 monitoring with viral load monitoring– Implement evidence-based algorithms to prioritise patients

Laboratory-based test Point-of-care test

Sample Plasma, DBS Fingerstick, heelstick

Sample volume

200 – 1000μl ≤100μl

Sample prep Simple, no contamination Simple, part of POC test

Consumables Minimal, open access Minimal (1 lancet, 1 collection tube, 1 cartridge)

Reagents No cold storage, stable ≥40°C for ≥18 months

Part of cartridge, no cold storage, stable ≥40°C for ≥18 months

Power AC and battery AC, battery (≥8 hours), solar

Instrument Open access and polyvalent, 1 room, no contamination

Closed system, automated, small and lightweight, environmentally robust (heat, humidity, rigorous movement)

Hands-on time ≤1 hour ≤10 minutes

Time to result ≤1 day ≤30 minutes

Range Quantitative, all subtypes, ≥50 copies/ml

Quantitative / semi-quantitative, all subtypes, ≥1000 copies/ml

Training / skill Medium Minimal, basic (≤2 days), no precision pipetting

Regulation WHO PQ (opt CE, FDA) WHO PQ (opt CE, FDA)

Cost per test ≤$10 ≤$8

Instrument ≤$5000 (all required) ≤$1000 (single instrument)

Simplifying sample transport by using DBS• Quick processing of whole blood• Inefficient sample networks• Alternative: dried blood spots• Long distances, ambient

temperature• Time to result: e-health, m-health• Fingerprick DBS• NucliSENS EasyQ® HIV-1 v2.0 viral

load test (bioMerieux) for DBS• MSF validation of fingerprick DBS

in Malawi• Other tests for use with DBS?

NucliSENS EasyQ® HIV-1 v2.0 (bioMérieux)• Thyolo district hospital, Malawi• DBS validated• Real time NASBA (isothermal signal

amplification), RNA specific• Logistical challenges:

– laboratory infrastructure – unreliable power supply– unreliable water supply – provision of RNAse-free water– unreliable air-conditioning– non-adherence to cold chain transportation,

especially at customs– inability to find local laboratory technicians with

molecular biology expertise– lack of in-country trouble-shooting and

maintenance services

1. Extraction room

2. Amplification room

Generic HIV viral load assay (Biocentric)

• Nhlangano health center, Swaziland

• Open system, low cost• Real time RT-PCR (DNA and

RNA)• Logistical challenges• Use of plasma as a

sample type (use of DBS is research use only)

• Most of the other challenges as for the NucliSENS test

ExaVirTM Load Version 3 (Cavidi)

• Yangon, Myanmar (field site is in Shan state)• Subtype independent, relatively low cost, minimal lab

requirements, not as prone to contamination and not as dependent on precision pipetting as molecular lab tests

• ELISA of HIV reverse transcriptase activity

Challenges include:•Must be performed on plasma•Plasma must be frozen at -20°C•Need for back-up vacuum pump•Relatively low through-put for lab test•Good water quality is essential•Positive and negative controls must be

supplied in-house•Sample preparation to isolate the reverse

transcriptase enzyme is labour-intensive

Formore information,

please grab a copy of our viral load report

(also available on our website:

www.msfaccess.org)

Performance evaluation of SAMBA semi-quantitative HIV viral load test

for therapy monitoring in resource-poor settings

Dr. Suna Balkan

MSF Aids Working Group

Inclusions/month Cumulated patients under ART

0

1000

2000

3000

4000

5000

6000

7000

2001 2002 2003 2004 2005

Scaling-up in the MSF project Chiradzulu district, Malawi

Decentralisation

Task shifting Need for a POC VL

SAMBA system characteristics

• All HIV1 subtypes & recombinants• Threshold 1,000 copies/ml• Heat stability at 50°C

• Robust & simple instrument

• No or minimum electricity• Minimum handling• No risk of contamination• Turn around time allowing same

day result• Affordable cost

• Can detect Groups M, N, O & recombinants

• Cut-off at 1,000 copies/ml• Heat stable reagents; no cold chain

transport or storage• Isothermal amplification with

simple visual detection • Low power requirement 350W• Preloaded reagents in a closed

cartridge• Test time = 90 minutes with

throughput of 24/day at 6.5 hr working day

MSF requirements SAMBA

Visual readout of SAMBA semi-quant VL test

<1,000 cp/ml ≥1,000 cp/ml

SAMBA system

SAMBA-prep(sample extraction)

SAMBA-amp(amplification)

1 to 4 samples per run

* Roche TaqMan accuracy: +/- 0.3 Log per package insert

Evaluation of SAMBA London St Thomas & Royal London Hospitals in 134 clinical samples

Concordance between SAMBA & Roche = 97.8 % (131/134)

< 500(<2.7 log)

500 – 2000(2.7- 3.3 log)*

>2,000 (>3.3 log) Total

SAMBA >1,000 2 2 34 38

SAMBA < 1,000 93 2 1 96

Total (%) 95 (71%) 4 (3%) 35 (26%) 134

Roche Taqman v2 (copies/ml)

• Malawi– 13.2 million population mainly rural – 1 million HIV-infected

• MSF project based in a rural district– 1 hospital (laboratory),10 health centres– HIV care in 2000,decentralisation in 2003– 25 000 patients followed under ART – 80% followed in the 10 decentralised health centres– Integrated project with MOH

MSF Chiradzulu project background

MSF Arua project background

• Northwestern Uganda• Arua + catchment population : 1,5 M• HIV prevalence 3%• ART project since 2002• Arua District Hospital• 7000 patients followed under ART • Integrated project with the MOH

SAMBA tested on-site by MSF technician

Roche TaqMan v2 at Royal London

Hospital

Abbott RealTime PCR at Addenbrooke

SAMBA field trials in Malawi and Uganda

200 HIV+ patients in Malawi 154 HIV+ patients in Uganda recruited

from HIV clinic during routine visit

200 µl fresh plasma Frozen plasma shipped directly

Results to MSF

Discordant SAMBA/Roche

All testing blinded to each other

Malawi results – SAMBA vs Roche TaqMan v2

Viral Load (cp/ml) < 500(<2.7 log)

500 – 2,000(2.7- 3.3 log)*

>2,000 (>3.3 log) Total

SAMBA >1,000 4 4 46 54

SAMBA < 1,000 142 4 0 146

Total (%) 146 (73%) 8 (4%) 46 (23%) 200

Overall concordance with Roche v2 = 98% (196/200)

Roche TaqMan version 2

* Roche TaqMan accuracy is +/- 0.3 Log per package insert

Uganda results – SAMBA vs Roche TaqMan v2

Viral Load (cp/ml) < 500(<1.7 Log)

500 – 2,000*(2.7-3.3 Log)

>2,000 >(3.3 Log) Total

SAMBA >1,000 2 0* 56 58

SAMBA < 1,000 90 2* 4 96

Total (%) 92 (60%) 2 (1%) 60 (39%) 154

Overall concordance with Roche v2 = 96.1% (148/154)

Roche TaqMan v2

* Roche TaqMan is 0.3 Log accuracy (package insert)

Conclusion

• SAMBA platform is much simpler than currently available molecular technologies which require highly-trained personnel and sophisticated infrastructure only available in centralised laboratories

• SAMBA device is much easier to handle and being a closed system, prevents contamination by amplicons

• Staff training requirement for SAMBA is minimal • SAMBA can be implemented in lower healthcare levels such as district hospitals or

health centres with a basic laboratory but supplied with electricity• Routine use of Samba will be now implemented in Arua and Chiradzulu with on going

evaluation • Will improve HIV care in a decentralization & task shifting strategy

Virological efficacy of ART over time at MSF sites in Arua and Chiradzulu

<0.5 0.5-1 1-2 2-3 3-4 4-5 5-6 >60%

20%

40%

60%

80%

100%

<40

<1000

Years on ART

% o

f pat

ient

s

> 65 % of patients on ART have VL < 40 cp/ml after 6 months> 80 % of patients on ART have VL < 1,000 cp/ml after 6 months

n = 284

Distribution of viral loads in treated and untreated individuals in Malawi & Uganda

0%

10%

20%

30%

40%

50%

Roche TaqMan v2 viral load (cp/mL)

% o

f pat

ient

s

> 1x106

1,000 cp/ml

1x105 1x104 1x103 1x102 <100 <40