High sensitivity of a novel rapid test for the diagnosis of clinical and subclinical Plasmodium falciparum infections in a high transmission setting in Burundi

Abstract

Rapid diagnostic tests (RDTs) are a key tool for the diagnosis of malaria infections among febrile and subclinical individuals. Low-density infections, and deletions of the P. falciparum hrp2/3 genes (encoding for the HRP2 and HRP3 proteins detected by many RDTs) present challenges for RDT-based diagnosis. The novel Rapigen Biocredit three-band Plasmodium falciparum HRP2/LDH RDT was evaluated among 444 febrile and 468 subclinical individuals in a high transmission setting in Burundi. Results were compared to the AccessBio CareStart HRP2 RDT, and qPCR with a sensitivity of <0.1 parasites/µL blood. Sensitivity among clinical patients was 80.0% (250/313, either of HRP2/LDH positive), compared to 73.2% (229/313) for CareStart (P=0.048). Among subclinical infections, sensitivity was 72.3% (162/224) compared to 58.5% (131/224) for CareStart (P=0.003), and reached 88.3% (53/60) in children <15 years. No (0/362) hrp2 and 2/366 hrp3 deletions were observed. In conclusion, the novel RDT showed improved sensitivity for the diagnosis of P. falciparum.

Factors Affecting the Performance of HRP2-Based Malaria Rapid Diagnostic Tests

“…Highly sensitive RDTs (hsRDTs) claimed to have a 10-fold increase in sensitivity compared to the RDTs routinely available in the market [ 31 ]. Therefore, they provide the opportunity to more efficiently detect cases of malaria with low-parasitic densities and asymptomatic infections [ 32 ]. Traditional RDTs have a limit of detection (LOD) of approximately 800 pg/mL and show decreased sensitivity to detect low-density Pf infections (<100 parasites/µL).…”