Performance of Malaria Rapid Diagnostic Test in Asymptomatic Malaria Cases in Stable Transmission Area in Kisantu, Democratic Republic of Congo

Abstract

Background: Democratic Republic of Congo has shifted from pan test to mono-specific malaria RDT tests. A new Histidine rich protein 2 (HRP2)-based Rapid Diagnostic Tests for malaria diagnosis was then implemented. Objective: This study evaluated the performances of this new diagnostic tool compared to the thick smear as the gold standard. Method: The study was conducted in Kisantu Health zone in the Democratic Republic of the Congo (DRC) where malaria is known as endemic disease. Asymptomatic children aged between 0 and 10 years were included in the study. Malaria tests such as Rapid Diagnostic test (RDT) and blood smear were perform in all enrolled children. Blood smear was considered as a reference test. In the performance analysis, only thick positive smears confirmed as Pf by thin smear were considered positive in calculation. The sensitivity, specificity and positive and negative predictive values of CareStart Malaria Pf (HRP-2) RTD Ag compared to the thick smear. Result: The prevalence of malaria infection was 78.3% and 14.7% using rapid diagnostic test and thick blood smear, respectively. Considering the gold standard, proportion of false positives was 77.5%. The Sensitivity was 83.1% (CI95%: 72.4-94.9) and specificity was 22.5% (CI95%: 20.2-25.0). The Positive Predictive Value (PPV) was 15.2% and Negative Predictive Value (NPV) was 88.9%. It appears that the HRP2-based test presently used in the Democratic Republic of Congo over estimates malaria infections. Conclusion: CareStart Malaria Pf (HRP-2) RTD Ag, currently in use in the DRC detects a very high proportion of false positives. Those children falsely positive were subject to be treated unnecessarily. Therefore, there is need of adapting the choice of RDT for malaria policy accordingly.