We used a bead-based serological assay to measure lactate dehydrogenase (LDH), aldolase (Aldo), and histidine-rich protein 2 (HRP2) levels in 196 children with Plasmodium falciparum malaria treated with effective antimalarials and followed for 28 to 42 days as part of therapeutic efficacy studies in Angola.
With the documentation of cases of falciparum malaria negative by rapid diagnostic tests (RDT), though at low frequency from natural isolates in a small pocket of Odisha, it became absolutely necessary to investigate the status of HRP-2 based RDT throughout the state and in different seasons of the year.
Rapid diagnostic tests based on histidine-rich protein 2 (HRP2) detection are the primary tools used to detect Plasmodium falciparum malaria infections.
This study seeks to compare the performance of HRP2 (First Response) and pLDH/HRP2 (Combo) RDTs for falciparum malaria against microscopy and PCR in acutely ill febrile children at presentation and follow-up.
RBC-D correlated inversely with parasitemia and lactate in knowlesi malaria and HRP2 in falciparum malaria, and it correlated with hemoglobin nadir in knowlesi malaria.
Posttreatment HRP2 concentrations were measured in samples obtained longitudinally from 537 individuals with P. falciparum malaria who were participating in efficacy trials in Angola, Tanzania, and Senegal.
An aptamer for specific detection of falciparum malaria holds promise as a new strategy for species-specific malaria diagnosis rather than the conventional HRP2 immuno-assay.
Hence the aim of the pilot study is to explore the sensitivity and specificity of RDTs using urine (collected non-invasively) for diagnosis of Plasmodium falciparum malaria and to assess the relation between parasite density in blood with HRP-2 Ag detection in urine.
Although WHO does not recommend the use of combined HRP2/pLDH testing in sub-Saharan Africa, these results suggest that combination HRP2/pLDH-based RDTs could reduce the impact of false-negative HRP2-based RDTs for detection of symptomatic P. falciparum malaria.