Laboratories And EQA for effective
Tuberculosis Control Programe
Gokarna Raj Ghimire
Senior Medical Technologist
National Tuberculosis Center
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Introduction
• The global burden of TB is high
• Untreated smear positive cases are highly
infectious
• Nepal has steady case finding rate (75%)
• Treatment success rate (90 %)
• Slide positivity rate still on average 10 %
• DO NOT miss diagnosis
• DO CORRECT TREATMENT FULL DOSE FULL PERIOD
OF TIMR
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• Laboratories and lab networks are a fundamental
component of NTP.
• It provides testing for diagnosis, treatment monitoring,
evaluating the success of treatment and surviellance.
• Laboratory should do:
– New Initiatives
– Strengthen the lab capacity including HR
– Implement rapid and new diagnostic tests
– Implement quality system and safety system
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Strength of lab network reflects the success of NTP
Good quality microscopic centers (ZN technique)
Fluorescence Microscopy (Auramine techniques)
Culture and DST (Solid and Liquid)
Molecular techniques, (Gene Xpert, LPA)
Trained staff
Good Quality management System
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Microscopy
• Microscopy remains mainstay of rapid, cheap, easy
method of TB case detection
• ZN smear is still the most common test.
• Low sensitivity, so look for advanced method
• FM has high sensitivity
• Concentrated technique with FM has more higher
sensitivity
• Monocular microscope-binocular-fluoresence
microscope
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Container
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Culture and DST
• Confirmed diagnostic test
• Need high quality lab infrastructure, equipments and
HR
• Useful diagnostic tools for EP cases, childhood TB
cases, HIV-TB cases, MDR-TB Cases, XDR-TB cases
• FLD/SLD DST
• Facilities are available at NRL/NTC and GENETUP
• Purposed places: BPKIHS Dharan, RTC Pokhara, Mid
west Surkhet
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Mycobacterial Colonies on Egg based Culture
Medium (LJ medium)
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Nucleic Acid Amplification tests
• Gene Xpert : Fully Automated, Cartridge based,
Real Time, Nucleic Acid Amplification Test (NAAT)
• LPA: Manual PCR, Detection by Hybridization strip,
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Specimen Transportation
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EXTERNAL QUALITY ASSESSMENT (EQA)
IN NEPAL FOR SPUTUM MICROSCOPY
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External Quality Assessment (EQA)
• A system for objectively checking the laboratory’s
performance using an external agency or higher
authority
• Ensures customers (physicians, patients and health
authorities) that the laboratory can produce
reliable results
• An indispensable part of a laboratory quality
management system
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The Quality System
Quality System
Essentials (QSE)
Set of coordinated
activities that function
as building blocks for
quality management
EXTERNAL
QUALITY
ASSESSMENT
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Requirements Regarding EQA
• The laboratory should participate in inter-laboratory
comparisons such as those organized by EQA
schemes ( Total 554 Microscopy centers are exists in
Governmental organization and NGO/INGO/Private
institution)
• The lab management shall monitor the results of
EQA and participate in the implementation of
corrective actions
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EQA Benefits
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Allows inter-lab comparison of performance
Serves as an early warning system
Identifies systematic problems
Provides objective evidence of laboratory quality
Serves as an indicator for focusing improvement efforts
Identifies training needs
Source of continuing education
Source of material for practice
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EQA for AFB Smear Microscopy
Consensus document:
External Quality Assessment
for AFB Smear Microscopy
(2002)
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Current EQA Structure
QCA at National Quality
Control Centre (NTC)
National
Problem slides
If some slides
Regional incorrect
DTLO holds meeting
to discuss results
with PMCs
DTLO
District
Local
QCA at Regional Quality
Control Centre
PMC
= Slides
PMC
PMC
= Feedback
If 100% slides
correct
DTLO
PMC
PMC
Structure of Quality Control System
Central level
National TB Centre
Regional level
EDR
GoN/BNMT
CDR
NTC
WDR
RTC
DPHO/DHO
Periphery level
Microscopy Centre
MWDR
GoN
District level
FWDR
GoN/FAITH
Flow of Quality Control System
On Quarterly Basis
2. Send Collected Smear Slides With Form (QC 1)
Selecting by using LQAS
DTLO
3. Cross Check
1. Keep all Slides
Microscopy
Centre
Report Feed-Back
(QC 3)
Assessment (QC 2)
Regional Quality
Control Centre
RTLO
5. Supervision
Refresher Training
EQA Methods
for AFB Smear Microscopy
External Quality
Assessment (EQA) –
a process to assess
laboratory performance;
allows to assess labs’
capabilities and
performances by
comparing their results
with those obtained in
other labs in the network
Panel testing
Blinded rechecking
On-site supervision
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Panel Testing Process
• NRL sends out sets of stained and/or unstained
sputum smears for testing
• Laboratory technicians analyze smears and return
results to NRL
• Results are evaluated, scores are sent to
participants
• Appropriate corrective actions are undertaken (and
documented), if needed
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Blinded Rechecking
• Random sampling of routine slides from a peripheral
laboratory for rechecking by a higher-level laboratory
• The widely used system for rechecking of “10% of
negative and 100% of positive smear” is no more
recommended
• The proposed blinded rechecking method is based on
the Lot Quality Assurance System (LQAS)
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On-Site Supervision
• Periodic visits to the laboratory to assess laboratory
practices to:
• Obtain a realistic picture of laboratory practices
• Provide assistance with problem areas, including training
• Laboratory vs. TB supervisors
• When planning site visits, to consider:
– Frequency
– Use of checklists
– Follow-up visits
• Monitoring corrective actions
• Training
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EQA methods: Which one is better?
• Advantages and drawbacks for all types
• Influencing factors:
– NTP goals set up for laboratory services
development
– TB prevalence in the country
– Centralization / decentralization of health services
– Resources available and projected
• Cost, time
• Logistical questions
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Panel Testing
ADVANTAGES
DISADVANTAGES:
•Low workload for a peripheral
•Does not measure routine
center
•Improves laboratory credibility
•Rapid response countrywide
possible
•Use of stained and unstained
smears can help to identify the
source of a problem
•May lead to identification of faulty
equipment
performance
•High workload for NRL
•May not be motivating to
improve daily performance
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Panel Testing: Indications for Use
• Minimal first step for EQA with limited resources
• Rapid assessment of gross deficiencies
• Evaluates proficiency of laboratory technicians
prior to and following training
• A tool during problem-oriented supervision
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Blinded Rechecking
ADVANTAGES
DISADVANTAGES:
•Low workload for a peripheral
•Higher workload for a higher
laboratory
•Motivates to improve daily
performance
•Reflects reality of routine
performance
level center
•Needs close adherence to
elaborated procedures
•Can not be used with very low
positivity rates
Indications for use:
• The best method for evaluating lab performance
• Countrywide
• Ongoing and permanent
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On-Site Supervision
ADVANTAGES
•Direct personal contact
•Motivating to staff
•Observation of actual work
•Identifies causes of errors
•Permits verification of equipment
DISADVANTAGES:
•Usually poor coverage
•Labor intensive
•Costly
•Needs very good
supervisors
quality and function
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On-Site Supervision: Indications for Use
• Complementary to rechecking and panel
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testing for constructive feedback and problem
solving
Implementation and monitoring of quality
improvement measures
Data collection and flow of information among
laboratory levels
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EQA: Important Issue
Blinded rechecking or panel testing
should be complemented by very
targeted problem-oriented
supervision conducted by a trained
staff
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Situational Analysis Of EQA Nepal
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Medium Size Population;
Vast different territory
Low Burden of TB
Several hundreds of geographically dispersed peripheral
laboratories
• RQCC’s (Intermediate laboratories’) infrastructure is not
well developed; many intermediate labs experience lack
of staff
• NRL/NTC is not well equipped and sufficient staffed
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Key Messages (I):
• EQA can be defined as a system for objectively checking the
laboratory’s performance using an external agency or
facility
• EQA for AFB smear microscopy allows participating
laboratories to access their capabilities and performances
by comparing their results with those in other laboratories
in the network
• EQA for AFB sputum smear microscopy include three
methods:
– Panel testing
– Blinded rechecking
– On-site supervision
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Key Messages (II):
• Effective use of each of EQA methods will highly
depend on resources, NTP goals, TB prevalence,
health services’ structure and the stage of
laboratory quality assurance activities development
in the country
• Blinded rechecking or panel testing should be
complemented by very targeted problem-oriented
supervision conducted by a trained staff
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Thank You
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