# Presentation: 681646

## Implementation of an AFB Smear Microscopy External Quality Assessment Program in ZambiaGABERONE BOTSWANA29, July 2003 

**BWALYA RUTH TEMBWE**
*** ****PRINCIPAL SCIENTIFIC  OFFICER*
*CHEST DISEASES LABORATORY*
*(NATIONAL REFERENCE LABORATORY FOR TUBERCULOSIS)*
*LUSAKA, ZAMBIA*

## Tuberculosis (TB) in Zambia

- 512 TB cases per 100,000 population (10.6 total pop.)
- Direct AFB sputum microscopy
-      - most cost effective for diagnosis and monitoring treatment
- 154 AFB smear microscopy centers
- National Reference Laboratory (CDL) in Lusaka
- No previous organized system for assuring the quality of TB smear results in laboratory network

## Map of Zambia showing 9 Provinces

**Map of Zambia showing 9 Provinces**

## Zambia TB Microscopy National Action Plan for 2002 – 2003

- National Action Plan for AFB Smear Microscopy
-      external quality assurance (EQA) developed June 2002
- Central Board, MoH, CDL and Province Laboratory Managers
- Onsite laboratory evaluation form modified by lab managers
- Based on the External Quality Assurance Guidelines* developed by International Work Group
- Support  for EQA from CDC; also JICA and WHO

- *http://www.aphl.org/Infectious_Diseases/EQA.cfm

## Components of AFB Microscopy External Quality Assurance 

- (1)  On-site evaluation of the microscopy laboratory
-         -microscopes, registers, reporting results, techniques, etc.
- (2)  Panel testing (PT) of technicians who read and report AFB smears
-         -competency in detecting and quantification of AFB in smears
- (3)  Blinded rechecking of smears randomly selected by a statistical method
-         -determines # of errors in a statistical sample of slides read in a laboratory

## Implementation of EQA Activities

- In phases starting with 9 provincial hospital laboratories
- On-site evaluation was done consecutively with  PT in each province hospital laboratory (September 2002 to January 2003)
- Province Mangers will conduct onsite evaluation and PT in their respective district and rural laboratories

##  Implementation of Panel Testing 

- CDL determined the # AFB technicians in each Province Hospital Laboratory for PT slide preparation
- Communication with Public Health Directors regarding EQA activities
- Preparation of schedule for onsite laboratory evaluation and Panel Testing (PT) of AFB microscopists in each province
- Technical support and consultation with CDC-Atlanta on preparation and validation of slides to be used for PT

## Implementation of EQA Activities (continued)

- Batches of PT smears developed at CDL based on EQA guidelines
- Smears were: negative; 1-9; 1+; 2+ and 3+ AFB
- AFB in smears validated at CDL, UTH & CDC-Atlanta
- 10 slides per technician; 5 stained at CDL and 5 un-stained to be stained by technicians
- Successful completion of PT challenge was at least 80% score

**Notes:**
Explain the use of containers were used because of the capacity of new centrifuge.

## Onsite Evaluation and PT 

- Total time involved was at least three days for each laboratory
- Courtesy calls to Province Health Director and Laboratory Administration
- Orientation of Laboratory staff to PT and onsite evaluation process
-         Panel testing about three hours
-           11⁄2 - 2 hours for 10 slide test evaluation
-          5 slides pre-stained at CDL; 5 stained by each technician to be tested
- On site evaluation, about 2 hours
- Equipment, procedures and laboratory register assessed
- Corrective actions discussed with technicians, about 1 hour
- Scoring PT and documentation of onsite visit results
- Travel time one day

## Province Panel Test Results

- PT success rate 52% at province laboratories
- Types of errors:  high false negative and quantification were most common
- PT and onsite exercises were received positively by managers and technical staff
- Staff and managers were receptive to discussing opportunities for improvement
- Communication - a very important factor !!!

## Panel Test and Onsite Evaluation Workshop 

-    3 day re-training workshop
-  Re-training on quantification of AFB smears
- Appropriate preparation of stain reagents; specimen labeling, etc.
- Attention was given to equipment, reagent and technical needs in the laboratory
- New microscopes had been distributed to some laboratories; others were still in need
- Weigh balances were needed
- More detail on Zambia PT to be presented at IUATLD Meeting (Paris, France - October 2003)
- Participants were also oriented to the Rechecking program

## Implementing Blinded Rechecking  

- Determine # of smears performed in each laboratory
- Determine the number of positive smears in the laboratory
- Slide positivity rate
- Distribute slide boxes to archive slides consecutively for one quarter
- Storage of slides began on 1st April 2003
- For ease of random collection of slides:
-        - each sample received in the laboratory is given an
-          individual number
- May 2003 - supervisory visit to check on the progress of slide storage and management of laboratory register

## Initiation of Rechecking Program

- First supervisory findings:
- Some laboratories were following the recommended  procedures
- Two laboratories had not yet started; advised to commence on 1st July
- One laboratory was not grading the positive smears
- Random collection of smears for rechecking to begin on 10th July
- The numbering in the register should be carefully checked as some numbers are missed; e.g., after 1099 the next number was 2000 instead of 1100.

## Resources for EQA Activities

- Adequate number and dedicated staff at NRL
- Microscopes (some centers have one for all lab work); spare bulbs
- A reliable mode of transportation/vehicle and funds for food/lodging
- Computer for preparation of forms and communications
- Slide boxes to store 3-4 month volumes of slides per laboratory
- AFB Microscopy EQA Guideline for International Laboratories
- Consultation with others involved in AFB Microcopy EQA activities

## Acknowledgements

- Financial and technical support:
-      Centers for Disease Control and Prevention-Zambia
-       Japanese Inter Cooperation Agency
-       World Health Organization
-       Ireland AID
- Consultants:
- 	Centers for Disease Control and Prevention,  Atlanta, GA (USA)
- 		Dr. John Ridderhof
-        	Dr. Bereneice Madison

***TWATOTELA***** **