Journal of Blood Disorders & Transfusion

Abstract

Evaluation of the Diagnostic Performance of OptiMAL-IT® Test for the Detection of Plasmodium falciparum in South-West Saudi Arabia

Wael Alkhiary

Background: OptiMAL-IT® test is a rapid malarial diagnostic test designed to detect at least one protein specific to Plasmodium LDH (pLDH). The diagnostic performance of OptiMAL-IT® was evaluated and compared with the microscopic examinations of thick and thin blood smears, taken as gold standard for the diagnosis of malaria infection.

Methods: A four-year retrospective analysis was done for 238 consecutive suspected patients and 475 apparently healthy blood donors, who were tested for malaria at Rijal Almaa Central Hospital, Asir region, Saudi Arabia between January 2011 and January 2015.

Results: Of the 713 subjects, 74 (10.38%) were confirmed with Plasmodium falciparum infections by cross-checking. All 74 patients (61 patients; 82.4%, and 13 blood donor; 17.6%) were accurately diagnosed with malaria by routine microscopy. 28.15% (67/238) of patients and 3.37% (16/475) of blood donors were positive for malaria by OptiMAL-IT test. OptiMAL-IT® had the following performance indicators for detection of P. falciparum among patients, and blood donors enrolled: Sensitivity—98.36% [95% CI (90.02–99.91)], 100% [95% CI (71.66–100)]; Specificity—96.02% [95% CI (91.65–98.25)], 99.35% [95% CI (97.96–99.83)]; Predictive values for positive tests—89.55% [95% CI (79.06–95.34)], 81.25% [95% CI(53.69–95.03%)]; Predictive values for negative tests—99.41% [95% CI (96.27–99.97)], 100% [95% CI (98.97–100)]; Likelihood ratio for positive tests—24.7, 155; Likelihood ratio for negative tests—0.017, 0.00.

Conclusions: The diagnostic performance of OptiMAL-IT malaria test seems to be satisfactory, particularly as a good negative test. OptiMAL-IT can assist in the diagnosis of malaria cases and can be considered for quick screening of blood donor in potentially-endemic settings to prevent transfusion transmitted malaria.