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2014/05/05
1
Beyond Implementation:Health systems strengthening and
focus on high risk populations2011-2014
Professor Wendy Stevens
Department of Molecular Medicine and Haematology,
University of the Witwatersrand and
Head of National Priority Programs, NHLS
On behalf of the GeneXpert Team
TB Disease Burden in South Africa(WHO 2013 TB report)
• World’s 2nd highest incidence rate (1000/ 100 000/ year) (2012)
– Mining populations 4000/100,000:
– Correctional Services 4500/100,0000
• 63%-77% HIV prevalence in incident TB cases
• “Missed cases” remains a problem: (World’s 2nd highest in 2012)
• Increasingly smear negative
• South Africa reports the most XDR-TB cases in the world and annual
notifications have increased from 467 in 2009 to 1 596 in 2012. About 10% of
MDR-TB cases have XDR-TB
•WHO Strong Recommendation 2010: “The new automated DNA test for TB should be used as the initial diagnostic test in individuals with presumptive MDR-TB
or HIV/TB” (i.e. Most in SA)
•Pillars of SA National Strategic Plan: (2012-2016)•Minister of Health’s call in 2011
•Universal testing for HIV and screening for TB
South African experience highlighted areas for program strengthening
Priority Programs: general program: change from vertical management
•Linkage to care: CDC, BMGF, GF
•Focus on high risk populations: MDR, correctional services, mines
•Smooth implementation of EPTB and paediatric specimens
•R&D on other assays
Operational Challenges: Some solutions
•Improved technical and clinical training; Adherence
•Need for laboratory information systems to link with clinical data seamlessly
•Need for quality system components:
– Verification
– Remote monitoring; M&E for errors
– External quality assessment (pre – post analytical)
– Remote calibration
100% Coverage as per NDoH plan in public sector.
• Implementation in all original smear microscopy
centres: in a 3 phased approach, HBD first
• 207 centers across the 9 provinces
• Phased implementation started March 24th, 2011
• To date >3,2 mill tests performed to date; 60% of
global cartridges procured
• 289 analyzers: GX4 (95); GX16(186);GX48(1)
• 7 GX 80’s have been purchased and 5 installed to
improve capacity, but also assist with increased no's
expected for high risk populations
• 4th phase: High risk populations: correctional
services, mines and peri-mining communities and
MDR/XDR
Lab-based teaching
•916 technical staff trained
•3968 Clinical staff trained
•27 Master trainers for laboratories
•3 Master clinical trainers
Xpert contd…
2014/05/05
2
GeneXpert Cumulative data (March 2011-March 2014)
GeneXpert volumes, MTB detected: ~3.2 million tests to date (cumulative average 13% positivity) : geographical variation
Features:•Provincial summary District summary•Test volume trends MTB detected volumes (now at lab level)•Rif resistant volumes (now at lab level) Error rates•TATs Monthly uptake
GeneXpert volumes, RIF resistant (7%): stable average with geographic variation
GXP Test Volumes 2011-2014
0
50000
100000
150000
200000
250000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
2011 3152 12920 15970 17989 19290 23912 26212 32002 32040 23452
2012 30961 36346 44854 36843 48581 53011 50174 57056 63394 83940 92918 62038
2013 90571 98228 116096 119537 154254 127508 182713 201202 194136 196844 185474 117490
2014 171834 155073 205140
No
. o
f Te
sts
GXP Volumes 2011-2013
Significant algorithm simplification requiredAdherence to laboratory algorithm
• Cumulative results: 41% (culture + LPA + indeterminate/no result)• Steady improvement in adherence to laboratory diagnostic algorithm (see slide 2)
• EXIT-RIF study: laboratory does not equate to those receiving treatment
Annual Algorithm data Note: steady increase in RIF resistance detection: 2011-2013
Reduction in culture usage in favour of LPA over time
Marked increase in RIF resistance detection in all 9 provinces over time
Algorithm adherence improves with time
South Africa: Notified cases of MDR-TB and enrolments on MDR-TB treatment 2009–2012 (WHO 2013 TB report)
• NOTIFIED CASES ;•2009: 9070
•2010: 7386
•2011: 10085•2012: 15419
• CASES ENROLLED ON MDR-TB TREATMENT:
•2009: 4143
•2010: 5402•2011: 5643
•2012: 6494
2014/05/05
3
Evaluation of the GenoType® MTBDRsl to screen for extensively drug-resistant tuberculosis in South Africa
Lynsey Stewart-Isherwood, Francesca Conradie, Kathryn Schnippel, Natalie Beylis, Riana Louw, Pamela Diniso, Amanda Axcell, John Dewar, Adriano Duse
Submitted to the Journal of Clinical Microbiology in April 2014
Setting: Dedicated drug-resistant tuberculosis (TB) hospital in South Africa.
Objective: To rapidly screen for XDR-TB within a high MDR-TB, HIV co-infected population.
Design: Prospective cohort of 150 newly admitted patients to Sizwe Hospital.
GenoType® MTBDRsl line probe assays (LPAs) were performed directly on sputum and indirectly on culture isolates for specimens collected at admission. Results
were compared to gold standard liquid culture and drug susceptibility testing (DST) for ofloxacin (OFX) and kanamycin (KAN).
Previous work in SA tested for OFX and Amikacin with good results, Barnard et al 2012
Specimen type n Prev (%) Sensitivity (%)
95% CI
Specificity (%)
95% CI
PPV (%)
95% CI
NPV (%)
95% CI
*OFX smear + 35 25.7 (12.5-
43.3)
100.0 (66.4-
100.0)
100.0 (86.8-
100.0)
100.0 (66.4-
100.0)
100.0 (86.8-
100.0)
*OFX smear - 19 10.5 (1.3-
33.1)
50.0 (1.3-98.7) 100.0 (80.5-
100.0)
100.0 (2.5-
100.0)
94.4 (72.7-99.9)
OFX culture 58 22.4 (12.5-
35.3)
100.0 (75.3-
100.0)
95.6 (84.9-
99.5)
86.7 (59.5-
98.3)
100.0 (91.8-
100.0)
*KAN smear + 35 11.4 (3.2-
26.7)
50.0 (6.8-93.2) 96.8 (83.3-
99.9)
66.7 (9.4-
99.2)
93.8 (79.2-99.2)
*KAN smear - 17 17.6 (3.8-
43.4)
33.3 (0.8-90.6) 92.9 (66.1-
99.8)
50.0 (1.3-
98.7)
86.7 (59.5-98.3)
KAN culture 58 12.1 (5.0-
23.3)
42.9 (9.9-81.6) 100.0 (93.0-
100.0)
100.0 (29.2-
100.0)
92.7 (82.4-98.0)
Summary of prevalence of XDR-TB, as well as the sensitivity, specificity, PPV and NPV of the GenoType® MTBDRsl assay, compared to phenotypic DST. (Sizwe Tropical Disease Hospital, Gauteng, South Africa)
*The predictive indices of the direct smear-positive and smear-negative LPA results should be considered with reservation, as the numbers in this study are small. A larger
study is required.
L.E. Isherwood, et al.Similar KAN from Ignatyeva et al
1. High Risk Populations: MDRWHO report 2013: Address MDR as a public health crisis
Large Linkage to Care Project:• Design a comprehensive real-time m-Health solution for linking patients to care
using electronic records and accessing the NHLS central data warehouse and
laboratory information system, as well as the Edr, Etr.net and clinical data system
from the NdoH.
• Two NHLS databases can be used: the Central Data warehouse (CDW) and the
Laboratory Information system to which all Xpert analysers are interfaced that is
responsible for delivery of results
• To get maximum usage out of newly designed bi-directional sms printers
• Secondary objectives
• To implement the reporting structure needed to facilitate linkage to the following stakeholders
– National reporting of R-R cases to the National TB program managers
– Regional reporting to Provincial co-ordinators
– Facility reporting to clinical manager
– Reporting to the closest MDR centre, patients they should be looking for
– Ensure all bi-directional printers are functional and distribution is completed.
– Engage contact and tracing teams being introduced by the National TB program
through global fund in collaboration with JHU
CDC funded labGF: JHU
Global interim fund
On the ground.....
Staff complement/target to be hired between all stakeholders:
•52 Linkage Officers: (1 per district)
•18 Project Directors: who will report to the Implementation Science
Director
•180 Nurses: trained to initiate and manage TB, MDR-TB and HIV and
care
•2500 PHC PN/EN teams
•104 Mobile infection/PHC re-engineering teams
•10,000 CHW/CCG (symptom screening, tracing, simple screening tool)
•18 PHC Master Mentors (4 KZN/3 EC/2WC/2NC/2GP/1FS/LM/MP/NW)
2014/05/05
4
Total DCS facilities- red
Total NHLS GXP labs (207)-green
Map of all DCS facilities and all NHLS GXP labs
• 150 000 defenders in 242 facilities in 48 management clusters
• 50 000 in remand
• Overcrowding, isolation difficult, workflow, connection to community
• NOT A CAPTIVE COHORT
• Comprehensive plan for managing HIV and TB in the Correctional
Management Centres in South Africa- programme launched on World
TB Day 2013 (guidelines, program initiated)
• National Task Team established by NPP with all stakeholders: NDoH,
DCS, Clinicians, NHLS, human rights and advocacy groups, facility
security, M&E group, research group, donors; infection control
• Several models for implementation proposed:
– Placement of GeneXpert at all 242 DCS facilities
– Placement at 7 larger DCS management facilities and incorporate other
centres into NHLS lab network
– Use existing NHLS lab network
2. Correctional services plan initiated
NHLS proposed project plan for 6 selected DCS
sites : Total:18,298; 9.6% MTB; 7.54% RIF Peri-Mining Communities-Pilot
• To improve TB diagnosis and treatment in six districts:
1. Lejweleputswa (Free State),
2. Dr. K Kaunda & Bojanala Districts (North West),
3. West Rand (Gauteng)
4. Waterberg & Sekhukhune (Limpopo)
1 mobile team in each district
HIV and TB: 2GX4
Impact studies
– XTEND: Aurum/BMGF funded/NHLS: cluster randomized trial Xpert testing
sites with/out Xpert to review cost-effectiveness and impact.
– X-Phactor: Xpert MTB/RIF for people attending HIV care: interventional
cohort study to guide rational implementation.
– EXIT-RIF: UNC, NC/RTC/WITS/NIH funded/NHLS: Observation study: Rif
resistant patients identified arm 1 by culture, arm 2 by Xpert
MSF: Implementing Xpert MTB/RIF in Zimbabwe (S. Van Den Broucke, IAS 2012):
•Xpert doubled detection rate;
•Increased the no. of lab confirmed TB cases- less empiric diagnosis of TB;
•Triples/quadruples the number of MDR –TB diagnosed
RTC in central Karoo region (T,van den Handel: personal communication):
•Xpert increased case detection
•Pre-Xpert: 22% cases treated were smear negative, culture negative vs. 1% post Xpert .
•Pre-Xpert 21% patients initiated in 5 days, post expert 95% initiated in 5 days.
2014/05/05
5
Optimizing the impact of Xpert MTB/RIF on
treatment outcomes of drug resistant TB
Evaluating the Xpert Impact on
Tuberculosis-Rifampicin Resistance
EXIT RIF Study
Annelies Van Rie, Lesley Scott, Yara Vossdelima,
Colleen Hanrahan, Natalie Beylis, Eugenne Elliott,
Cindy Hayes, Rob Warren, Wendy Stevens
Objectives
• To assess whether rapid diagnosis of RIF resistance leads to improved TB treatment outcomes.
• To determine phenotypic and genotypic drug resistance profile in patients diagnosed with Xpert-RIF resistance.
• To document management decisions and patient actions in the first 6 months following diagnosis of Xpert-RIF resistance.
Methods
• Study Design: Observational Cohort Study with two
arms.
• Sample size :474 total (237 per arm)
-One arm will be made up of individuals with RIF resistant TB by
culture-based drug susceptibility method or LPA on a sputum sample collected prior to TB treatment initiations
-The second arm will enrol individuals diagnosed with RIF resistant TB by Xpert MTB/RIF prior to the start of TB treatment.
-Enrolment period: 15 months. In Gauteng, Eastern Cape and Free State.
Embargo on results:Union meeting
Infinity installations
Sites
Province Laboratory Date
installed
Western Cape Greenpoint 18 Nov 2013
Free State Pelonomi 03 Dec 2013
Gauteng Tambo Memorial 03 Feb 2014
Gauteng Braamfontein 03 Apr 2014
Eastern Cape Port Elizabeth 17 Mar 2014
Gauteng CH Baragwanath Scheduled for
May
Gauteng Steve Biko To be re-
allocated
Challenges
• Infrastructural changes (Renovations)� Reinforcing door panels and floor
� Dedicated power points
� Redesigning of work area
� Removal of pipes (gas, water, waste, etc.)
� Crane required to lift machine
• LIS� Current barcodes too big causing
recurring gripper sensor problems – staff to manually cut
� New barcodes not compatible with TRAK-requires software modifications
Not a small endeavour…..
Pelonomi Laboratory; Free State
2014/05/05
6
Cost-effectiveness doesn’t equal affordability or uptake: linkage to care!
(Clouse, K et al, SAMJ 2012)
• Feasibility and impact of Gx at POC (~2hr test result).
– Concerns: Expanding Xpert to POC could result in important patient
benefits but requires substantial strengthening of primary care facilities
and investment in human resources (a minimum of two full-time staff
required to supervise sputum collection, process sputum, perform
assays, document and communicate results for an average of 15 TB
suspects daily). Some patients did not receive same day treatment due
to specimen preparation times.
Module Failures
Total Number of Modules Replaced: n=515 (of 3564)(14%)
Source of Error Frequency % No of
Sites
No of
Modules
Error Codes
Cartridge Related Issues 31 13.84 24 56 2037, 5011
Power Failure 7 3.13 6 13 2126, 4008
Sample Processing 38 16.96 27 69 2008, 5006, 5007, Invalid
Software Issues 5 2.23 3 9 2127, 4016
System Related Issues 72 32.14 59 130 1004, 1006, 1018, 2005, 2006,
2011, 2012, 2016, 2018, 2025,
2026, 2032, 2034, 2035, 4004,
4014
Temperature Related
Issues
71 31.70 44 128 1001, 1002, 2014, 2022, 4009,
4010, 4012, 4015, 4017
(n=405 attributed to module failure: 11.4%)
Summary of Module Failure errors
Cartridge
Relates Issues
14%
Power
Failure
3%
Sample Processing
17%
Software Issues
2%
Instrument Related Issues
32%Temperature Related Issues
32%Other
64%
• 89 (17%) were classified as calibration issues and 21 defective on installation (4%).
Most common: temperature fluctuations and instrument malfunction (63.95%)History of modules prior to replacement not known
• Costing and modeling revealed extended warranty costs 25% more than replacement
Dried culture spot program
• <3.5Ct SD across bulk batches
• <3.3Ct SD between skill cadres
• <3.3Ct SD between G3/G4
• Temperature stability: 4°°°°C to 37°°°°C (2.7Ct SD best at 37°°°°C)
• Stable to 12 months, therefore single shipment for whole year EQA (3/an)
One perforated DCS pushed out. Tested as a clinical specimen
Manufacture of bulk culture: single cell suspension
Manufacture of bulk culture: single cell suspension
Inactivation in Xpert SR buffer (2 hrs), confirmation by MGIT
Inactivation in Xpert SR buffer (2 hrs), confirmation by MGIT
Quantitfyusing flow cytometry: small particle counting (1um)
Quantitfyusing flow cytometry: small particle counting (1um)
Calculate bacterial events/ul
Calculate bacterial events/ul
Spot onto
Whatman
paper cards –
perforated
spots
Spot onto
Whatman
paper cards –
perforated
spots
Send to
sites for Gx testing
Send to
sites for Gx testing
US patent no: 8,709,712
Tbgxmonitor®
www.tbgxmonitor.com
Trial outcomes:
• All material compatible with Gx testing.
– No PCR inhibition
• Matrix (liquid or dried) not a distinguishing criterion for
use.
• Some material required additional consumables, some
not easy to open, transfer to cartridge.
• Room temperature optimal for product stability and
transport: 4/5 panels pass.
• Minimal variation in Ct is optimal for future use of Gx
for patient monitoring: 3/5 panels pass
EQA trial: 5 materials,11 Gx site SAMaterial requirement for Gx platform:
•Material must contain whole M.tb
•Testing procedure safe and compatible with Gx
•Non-laboratory skilled HCW’s able to perform testingin non-lab settings.
•Easy to transport and stable during ranges oftemperature.
•Cost-effective and sustainable for large scale Nationalprograms.
In press, JCM, 2014
Upload results from laboratory
Central review and
release of reports
Automated Platform for result reporting:
www.tbgxmonitor.com• Submission of CSV files to cloud (web)
• Automated processing and analysis
• Review of results
• Issuing of report and soon IR (investigational report)
Upgrading for
automated frame
score report
2014/05/05
7
DCS EQA Overview
1. DCS panel2. Informatio
n3. SOP4. Barcodes
Panels 1, 2 & 3 packaged in
one shipment
Investigation Report
Tri-annual email reminder (automated)
TBGxMonitor.com+ = Performance Report
Tri-annual EQA Report based on all
sites
DCS material: single cell culture, inactivated, quantified,
spotted on perforated cards.
Frame score Report
Summary of all DCS performance : 2011-2014
EQA: 3 panels per year (4 DCS per panel)
• 2012:
– Pilot ACTG: 6 participants, verification of
instruments and trial of EQA program
– Pilot SA: 11 sites, DCS plus 4 other panels.
• 2013:
– ACTG: 20 sites (24 instruments) completed full EQA
program (16 instruments with passing frame score,
1 with acceptable frame score, 7 with a frame score
of concern)
– SA: Site participation increased by 40% from round
1 to 3: 202 sites, Timeous submission rates
improved 24% with total program costs <0.1% of
test cost; 2068 DCS analysed, 98% generated
correct results and 1% instrument/assay/operator
error.
• 2014
– South Africa: 207 sites
– ACTG: 19 sites (26 instruments) in 13 countries
– International participants: 21 sites in 6 countries
(Ghana, Uganda, Tanzania, Kenya, Nigeria, Namibia).
Verification: installation,
maintenance, calibration
• Completed all in SA: 3432
modules upon installation.
• Use for relocated instruments
• Field campaigns.
• GLI/WHO accepted DCS for
international Gx verification
– Cepheid accepts shared shipping with
their instruments
• DCS also tested on other
platforms:
– Abbott MTB (under R&D)
– Hain LPA V1, V2 (Durban TB
conference June 2014, oral)
– EasyNATTM(China) (ASLM Cape
Town, December 2014, under
submission)
Challenges and Solutions (2011-2014)
Early (2011) Solutions Mid (2012- current) Solutions
NTCM, National plan,
Treasury support
Donor and NdoH funding Module failures Replacement, work in progress,
history not known
Algorithm: dual Phased, unavoidable
HBD first
Non-adherence to diagnostic
algorithm
Improvement-20-41%
Stock shortages Stabilized
Global forecasting useful
Clinical data collection Poor; EXIT RIF study
Verification of analyzer on site DCS development; patent:
WHO/CDC approval
Clinical training: MDR especially Linkage to Care program:
Funded by CDC (NHLS, JHU,
NDoH)
EQA material Developed with DCS
Trialled in SA, ACTG
Extended warranty For SA EW was 30% more
expensive
Forecasting difficult in 2014; GF
projects delayed
Global forecasting Massive scale up of QA material
required
Business plan under review
Clinical lag in training Trainers employed by NHLS and
GF
EPTB: CSF, FNA, purulent fluid,
etc
In-country study, WHO meta-
analysis; SOPs and policy
developed
Instrument performance
monitoring
Remote connectivity system High risk populations: DCS,
mines, MDRInitiation pressure
Paediatric Policy developed, although
/with culture
Monopoly Pipeline improving
Investment not wasted with
new assays at Cepheid
Monopoly Pipeline improving
Current EPTB Recommendations• Consultation with the NPP as well as its Microbiology Expert Committee as to best
practice based on local data and WHO recommendations.
• In order to ensure best patient care it has been proposed that the following
extrapulmonary and paediatric sample types may be tested with the Xpert MTB/RIF
assay:
• Cerebrospinal fluid, fine needle aspirates, gastric washes and lavages, other
fluids and tissue. (SOP development for specimen type, MBD)
• The NHLS would like to propose a testing algorithm for the abovementioned sample
types that includes performing culture either as a reflex test or in parallel.
In general for extrapulmonary specimens:
• If the GeneXpert result is MTB detected and rifampicin sensitive, no further culture
testing is required
• If the GeneXpert result is MTB not detected, further testing with culture is required
• If the GeneXpert result is MTB detected and either rifampicin resistant or
indeterminate, further testing with culture is required
For all paediatric specimens: it is recommended to perform GeneXpert and culture in
parallel
Tissue samples will be sent only to culture facilities (16)
Additional EPTB specimens other than FNA: Xpert Validation, preliminary results (Aug – Jan2013):
(Elizabeth Prentice, Lesley Scott, Gloria Nkuna, Natalie Beylis, Wendy Stevens)
Contamination: NALC-NaOH
decontaminate
Residual Xpert tested: >0.5ml
N=6112 routine EPTB specimens received ~6 months
Blood agar plate check for contamination
No contamination
Inoculate MGIT (~0.5ml)
Exclusions:Numbers received in total <10 (0.6%)
Not enough residual for Xpert – needs to exceed 0.5 ml after routine processing (30%)
• Most common specimens excluded:• CSF (37%), • Pleural fluid (14%) • Other aspirates (9%)
•Blood (1%)
EPTB
Xpert testingAccuracy of the Xpert MTB/RIF assay for
diagnosis of HIV-associated peripheral
lymph node Tuberculosis (in press).Van Rie A, Page-Shipp L, Mellet K, Scott L, Mkhwanazi M, Stevens W,
Sanne I, Menezes CN.
•152 adults referred for FNA
•Detection: 20%(n=30) smear +, 45%(n=69)
culture +, 49%(n=76) Xpert +.
Miscellaneous
(sample types <5)
1%
Miscellaneous
(sample types <30)
2%Blood
1%
Tissue
2%
Ascitic
fluid
2%
Pus
4%
Fluid
5%
Aspirate
9%
Pleural fluid
10%
FNA
27%
Cerebrospinal
fluid
37%
EPTB specimen types received in a
high throughput central laboratory,
n=6112 received in 6 months (April 2012-Jan 2013
• Sensitivity (culture reference)
– Xpert 94.2% (85-98)
– Did not differ by smear status or CD4 count
• Median time to diagnosis: lymph node TB
– 5 days microscopy
– 31 days culture DST
• Median time to treatment initiation
– 1 day using Xpert
• Median time for Rif resistance diagnosis
– 1 day using Xpert
– 47 days using culture/MTBDRplus
2014/05/05
8
Findings
• Overall sensitivity of Xpert compared to
MGIT=55.9% (CI 48.8; 62.8)
• Absolute number: 159 new cases (18%
of total referrals)
• Cost-effective?
MGIT and
Xpert positive,
113, 13%
MGIT pos,
Xpert
Negative, 89,
10%
MGIT negative
Xpert positive,
46, 6%MGIT negative
, Xpert
negative, 524,
61%
MGIT
contaminated,
Xpert
negative, 70,
8%
MGIT
contaminated,
Xpert positive,
19, 2%
MGIT and Xpert positivity
35613
2125
39
68
363
2014
3228
96
11077
1115
28
0
20
40
60
80
100
120
MGIT and Xpert positivity per specimen type
Xpert positive (incl culture contaminated) Culture pos Cul contam
3632014
3228
96
346
1220
2232
60
0
20
40
60
80
100
120
140
160
180
Xpert positivty of MGIT
Cul pos Xpert pos
38%
53%41%
59%
38%
67% 40% 50%
Cepheid/NHLS Remote Connectivity project
• Operational
dashboard for
real-time
monitoring of
results, errors,
resistance and
positivity rates
• Pre-configured
on all newly
installed
GeneXperts
User Workshop held 5-9th November to improve usability and facilitate design changes, Johannesburg
Xpert Calibration
• Calibration cartridges as opposed to swap-out module.
• Run cartridge as a normal Xpert assay (21minutes)
• Software calibration is performed once the calibration file has been
verified by Cepheid
• Calibration activation code: barcode to be scanned in the calibration software to activate the calibration (within three months
of issuing)
• New version of calibration cartridge launched in December 2013 to reduce the number of calibration failures.
User runs calibration
software & loads the
calibration cartridges
Cepheid analyzes data
Activation code is provided
to user to update calibration
Certificate issued
Customer
Service notified
for follow-up
Data sent by internet or by CD
Courtesy FIND 201
5 cartridges
Pre-post calibrationCt value analysis
• Probe A evaluated:
– Ct decrease after calibration
– Less variability in Ct after calibration
– Not statistically significant (p=0.175)
• 2000 tests or 1 year may not be the optimal indicator for
calibration but rather change in SD of Ct value/module
• Concern: the use of Ct for patient monitoring?
0
5
10
15
20
25
30
35
Ct
va
lue
Module name
Pre and post calibration Ct for probe A: Instrument 1
Pre cal
Post cal
0
5
10
15
20
25
30
Ct
va
lue
Module name
Pre and post calibration Ct for probe A:
Instrument 2
Pre cal
Post cal
Pre
calibration post calibration
Instrument 1 (n=13)
Average Ct 18.5 17.9
SD 4.4 1.6
Instrument 2 (n=11)
Average Ct 19.3 17.4
SD 2.2 1.5
Xpert MTB/RIF field testing for NDoH campaign
and using DCS to verify mobile Gx units. World TB day: 10 X GX16 in mobile vehicles
w1
Slide 48
w1 didnt we use this last imewendy.stevens, 28/08/2012
2014/05/05
9
Acknowledgements• Honorable Minister of Health: Dr Motsoaledi
• NHLS National Priority Program staff : Dr Leigh Berrie, Mr Sebaka Molapo
• NDoH: Drs Mametje, Pillay, Mvusi, Barron. Mabope, Nshuti
• Centre for Tuberculosis: Drs N. Ismail. L.Erasmus
• CDC for funding and support
• HERO team, G. Meyer –Rath, K. Bistline, Prof S.Rosen, Dr Billl Macleod
• Right to care: Prof Ian Sanne
• MM&H: Prof Scott, N. Gous, B. Cunningham, Dr E.Prentice
• Centre for TB excellence: Dr Bavesh Khana
• NHLS TB Expert working group: Dr A Whitelaw, Prof M.Nichol
• USAID, South Africa
• FIND: new work on EQA, R&D projects: Heidi Albert, Dr Boehme
• Aurum Institute: Prof G Churchyard, XTEND study and staff
• Bill and Melinda Gates foundation
• PATH
• Cepheid for new collaboration: regarding remote calibrations and connectivity