Locally manufactured malaria RDTs for Plasmodium vivax: A comparative study of kits approved by National Medical Products Administration in China

Purpose: Early and accurate detection of Plasmodium vivax malaria cases is essential for preventing the re-establishment of malaria transmission in China, given the widespread distribution of Anopheles vectors that transmit vivax malaria. In this study, we aimed to compare the performance of three different commercial malaria rapid diagnostic test (RDT) kits for screening P. vivax in China.

Methods: Microscopy was utilized to identify malaria parasites and to determine their parasite density levels. For the validation of microscopic findings and the genetic characterization of Plasmodium species, a nested polymerase chain reaction (PCR) technique was used. The Malaria RDT kits used in the present study encompassed products from BioPerfectus, which are designed for the detection of P. falciparum and other Plasmodium species, and kits from BlueCROSS and EGENS, tailored for the concurrent detection of P. falciparum and P. vivax.

Results: As a result, the overall agreement between malaria RDTs and nested PCR was almost perfect, with kappa values as follows: BioPerfectus (κ = 1.000), BlueCROSS (κ = 0.975, 95 % CI 0.971-0.979), and EGENS (κ = 0.950, 95 % CI 0.941-0.959). However, there was a statistically significant difference in the detection rate of P. vivax-positive samples from 94.5 % (104/110) to 100 % (P = 0.047). Furthermore, the agreement between the BlueCROSS and EGENS kits for detecting P. vivax-specific pLDH was almost perfect (P = 0.499, κ 0.973, 95 % CI 0.968-0.978), while the detection rates were lower for samples with low parasite densities (BlueCROSS: P = 0.007; EGENS: P = 0.001).

Conclusions: The detection capacity of the existing P. vivax-specific RDT kits in China needs to be further improved.