Scheme Design and Slide Composition:
A minimum of two cycle distributions will be done per year and this could be increased depending on client or participant requirements.
After each distribution, participants will have 21 calendar days (3 weeks) to analyse the panels and submit their results.
(10) Giemsa stained blood slides will be dispatched for each cycle
and these will be sourced from the Amref Malaria Slide Bank which already has a variety of prepared, validated slides.
Proposed slide composition:
Slide set |
Description |
Number of slides |
Component assessed |
Negative Slides |
Blood films with no parasites |
4 |
Will form part of species identification slides |
Count slides |
Slides with Pf |
3 |
To assess parasite quantitation or parasite density |
Single infection |
One of either Pf/Pm/Po/Pv (moderate parasitaemia) |
2 |
To assess detection and species identification of Plasmodium parasites |
Mixed infection |
Slides with Pf in addition to ether Po/Pm/Pv. |
1 |
To asses detection and species identification of Plasmodium parasites |
Each stained slide will have a unique identifier serialized as follows: Year-Cycle number-Slide number. For example 2024-C1-BS1 would be the first blood slide (BS1) of the first distribution (C1) in year 2024.
All slides in the panels will be independently verified by at least three microscopists with valid Level 1 competency certification according to criteria outlined in the WHO Malaria Microscopy Quality Assurance Manual. A summary of agreement between the independent microscopists will be used as the criterion for including slides for use in PT cycles.
Scoring system and statistical design:
For negative slides and positive slides with a single parasite species
a correct answer shall score 1 mark, for slides with mixed infections (2 parasite species), both parasite species correctly identified will score 1 mark, while one correct parasite species will score of 0.5 mark. 0 marks will be awarded for each incorrect answer.
3 marking categories will be evaluated as outlined below:
Parasite detection – All positive slides including single and mixed infections.
Species identification – All negative and positive slides including single and mixed infections.
Parasite quantitation ¬– Only count slides with P. falciparum.
A percentage score in each marking category will be calculated as (score obtained/total possible score for category*100).
An overall percentage score will also be awarded and this will be calculated as the average of percentage scores achieved in the 3 marking categories.
A percentage score of 80% and above per category or as overall percentage is considered acceptable, and lower scores (not acceptable) are expected to trigger implementation of corrective actions by the participants.
The overall score and scores per category will be provided in the performance feedback reports issued to participants after closure of each cycle.
The validity or microscopy skill of each participating site will also be further assessed by determining the percentage sensitivity and specificity. These are determined as follows:
Sensitivity: TP/ (TP+FN)
Specificity: TN/ (TN+FP)
Positive predictive value: TP/ (TP+FP)
Negative predictive value: TN/ (FN+TN)
TP=True Positive
FP=False Positive
TN=True Negative
FN=False Negative
Competence Result |
Result |
Sensitivity: Proportion of positive slides correctly read as positive |
≥80% |
Specificity: Proportion of negative slides correctly read as negative |
≥80% |
Detection of malaria parasites
Differentiation of Plasmodium species
Determination of malaria parasite density
Calculating sensitivity and specificity of microscopy technique
Results Submission
A standard form will be utilized for submission of results ERQ-MAL-FRM-002. Additional information about the survey distribution will also be captured or indicated as follows;
Date panels sent to facility.
Date panels received at facility.
Date results submitted by facility.
Date results received by PT coordinator.
This data serves to provide information about turnaround times for PT distributions and a summary is also included in reports provided to participants.
After completion of each PT distribution, participants submit results via an online informatics portal which will be accessed via the URL malaria.eareqas.org
The online informatics system will automate results' submission, scoring and issuance of preliminary feedback reports and com posite reports.
Immediate Feedback Report format
The Immediate Feedback Report provided to each participant includes information as outlined in ERQ-MAL-FRM-003-Feedback report. After participants submit their results via the informatics system, an automated comparison is done against the expected results and scores are awarded for each slide. The informatics system will then display the Immediate Feedback Report, which can be downloaded in PDF by the participant.
An option to appeal the report is available, to allow participants to register any dispute they may have with the scores awarded. Each case will be handled on an individual basis. No appeal can be made after 7 days of issuance of the Immediate Feedback Report.
A more detailed Composite Report will be compiled and provided to participants within 30 days of the cycle closure. This will include combined performance of all responding participants per slide and also overall combined performance in all marking categories.
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