Prevalence of plasmodium infection and accuracy of diagnostic tests for malaria infection in children under five in the health zone of Mont Ngafula1, an endemic area for malaria in Kinshasa, DRC

Abstract

Democratic Republic of Congo (DRC) is one of the five countries that carry half of the global disease burden. Yet, malaria is an entirely preventable and treatable disease, when currently recommended interventions are properly implemented. Such interventions include confirmation of malaria diagnosis through microscopy or malaria rapid diagnostic tests (MRDTs) for every suspected case, even in children under five years of age. This study aimed to assess the prevalence of malaria infection and the performances of MRDT, the SD-Bioline a HRP2/PanLDH test using microscopy and PCR as the gold standard in a population based survey in children under five years of age living in endemic transmission settings. This is a cross sectional based survey conducted in the health areas in the health zone of Mont Ngafula1 during the dry season from April to August 2012. A total of 812 children of 3 to 59 months of age were included from the 2 selected HA. The sensitivity, specificity, positive and negative predictive values with their CI 95% were 93.5% (90.0-97.1), 81.1% (77.9-84.2), 60.6% (55.0-66.3) and 97.5% (96.2-98.9), respectively, in the overall study population when using microscopy as the gold standard and 88%.2 (79.2-97.3), 92.0% (84.3-99.7), 88.4% (79.6-97.3) and 91.8% (84.0-99.7) respectively, when PCR was used as the reference test . The prevalence of malaria with microscopy was 24.9% (CI 95%: 21.0-26.7).The differences between PCR and microscopy with the specificity or and the PPV in the overall population might be due to the threshold detection of microscopy that does not detect very low parasite density. The results of this study show the limitation of the MRDT SD-Bioline, a HRP2/PanLDH test, on population based survey because of the risk of an overestimation of the infection prevalence in children aged less than five years.