Background: In Ethiopia, malaria case is declining as a result of proven interventions and the country launched malaria elimination strategy in targeted settings since 2017. Accurate malaria diagnosis and prompt treatment are the key components of the strategy to prevent morbidity and stop continuation of the transmission. However, the quality of microscopic diagnosis in general is deteriorating as malaria burden declines. Therefore, this study was carried out to
evaluate the competency of microscopists and the performance of health facilities on malaria microscopic diagnosis.
Methods: A cross-sectional study was conducted from August 01 to September 30, 2019 in nine Regional States and one city administration. A standard checklist was used for on-site evaluation, archived patient slides were re-checked and proficiency of microscopists was tested using WHO certified slides from national slide bank in public health institute. Strength of agreement, sensitivity, specificity and positive and negative predictive values were calculated.
Results: In this study, 102 health facilities (84 health centers and 18 hospitals) were included; from which, 202 laboratory professionals participated. In slide re-checking, moderate agreement (Agreement: 76.0%; Kappa: 0.41) was observed between experts and microscopists on malaria detection in all health facilities. The sensitivity and specificity of routine slide reading and the rechecking results were 78.1% and 80.7%, respectively. Likewise, positive predictive value of 65.1% and negative predictive value of 88.8% were scored in the routine diagnosis. By panel testing, a substantial overall agreement (A: 91.8%; K: 0.79) was observed between microscopists and experts in detecting malaria parasites. The sensitivity and specificity in detection of malaria parasites was 92.7% and 89.1%, respectively. Furthermore, in identifying species, slight agreement (A: 57%; K: 0.18) was observed between microscopists and experts.
Conclusion: The study found significant false positive and false negative results in routine microscopy on slide re-checking of Plasmodium parasites. Moreover, reduced grade in parasite species identification was reported on the panel tests. Therefore, implementing comprehensive malaria microscopy mentorship, in-service training and supportive supervision are the key strategies to improve the overall performance of health facilities in malaria microscopy.