Performance of microscopists in malaria diagnosis at two university community health centers, Mali 2020 to 2021

Abstract

Introduction: The World Health Organization recommends that suspected cases of malaria should be confirmed by a biological test before treatment. The diagnosis of malaria poses problems of error in several health establishments due to the lack of qualification of medical staff for microscopy. The aim of our study was to evaluate the performance of microscopists in malaria diagnosis in two University Community Health Centres (CSCom-U) in Mali.
Methods: A cross-sectional study was conducted from January to December 2020 in Ségué and from June 2020 to March 2021 in Banconi. A sample of 943 thick drop slides read by CSCom-U laboratory staff was re-examined by expert microscopists to assess the sensitivities, specificities and concordances of routine microscopy. The chi2 test was used with a significance level of 5% for comparison of proportions.
Results: The overall thick drop positivity rate was 46.3% using routine microscopy and 21.5% using expert microscopy. Using expert microscopy as a reference, the microscopists surveyed had an overall sensitivity of 85.2%, a specificity of 64.3% and a concordance of 68.8%. The diagnostic performance of the different species of Plasmodium falciparum was poor.
Conclusion: Our study revealed poor performance by microscopists in the CSCom-U laboratories studied. Specific training of laboratory staff in the microscopic diagnosis of malaria could improve the reliability of thick drop results.