Effectiveness of RDT and Microscopy in Detection of Malaria Parasite

Malaria presents a diagnostic challenge to laboratories especially in non-endemic malaria countries. Population movements and Travellers all contribute to presenting the laboratory with diagnostic problems for which it may have little expertise available. This study was aimed to compare the accuracy of two malaria Rapid Diagnostic Tests (RDTs); Optimal-IT® and one step RDT with the microscopic examination as the gold standard. Between June 2013 to January 2015 blood samples were collected from 78 patients, attending the internal medicine department at King Faisal specialized hospital at Taif, Saudi Arabia. Microscopy and Rapid Diagnostic Tests (RDTs) were done locally and the accuracy was evaluated. In this study detected 61 (78%) malaria positive slides, while 65 (83%) and 64 (82%) positive samples were detected with Optimal-IT and One Step Malaria Antigen Rapid Tests respectively. Optimal-IT sensitivity (98%), specificity (71%), positive predictive value (92%), negative predictive value (92%) and diagnostic accuracy (92%) whereas, one step RDT test showed 97%, 71 %, 92%, 86%, 91% respectively. However, the differences in detection rates of these diagnostic tests were not statistically significant (P>0.05). RDTs are considered the best option in health areas specially with limited laboratory services despite the problems related to their accuracy. However, this study showed that the accuracy of RDTs is not always satisfactory when performed in clinical laboratories.