Validity of Rapid Diagnostic Test compared to Light Microscopy for Malaria Diagnosis at Amana Clinic in Khartoum State, 2020

Abstract

Background: Early diagnosis and proper management are important issues in malaria control. Since malaria is a serious disease and highly endemic in Sudan, there is a need to identify the best diagnostic tools to help in the proper management and control of the disease. Rapid diagnostic tests (RDTs) and microscopy are routinely used for the diagnosis of malaria in Sudan. This study was conducted to assess the validity of RDTs of malaria compared to microscopy, using sensitivity and specificity of the RDTs against the standard method (Light Microscopy).

Materials and Methods:  One hundred patients with a clinical diagnosis of malaria attending Amanah Clinic Laboratories were tested by two methods: (a) Peripheral thick and thin blood films for the light microscopy diagnosis and (b) immunochromatographic test (ICT) for Malaria as a RDT. The results were compared using the sensitivity and specificity of the ICT against light microscopy.

Results: The ICT detected Plasmodium species infection with a sensitivity of 89%, specificity of 86%, positive predictive value was 99% and negative predictive value was 31.7%.

Conclusion: Our study shows that diagnostic accuracy of RDT was suboptimal compared to the gold standard method of microscopy.However; RDT is a valid diagnostic test for the majority of malaria cases, because it’s quick and easy to use. In difficult cases, microscopy in expert hands remains the gold standard method and the final court of appeal