Evaluation of three rapigen biocredit point-of-care tests for malaria case management in Lagos, Nigeria.

Abstract

Introduction: Histidine-rich protein 2 (HRP2) antigen kits are widely used for malaria diagnosis in tropical regions due to their heat stability. The Plasmodium Lactate Dehydrogenase (pLDH) used in BIOCREDIT® malaria test kit is claimed to be heat-stable. This study aimed to evaluate the heat stability and field performance of three BIOCREDIT® kits.

Methodology: A cross-sectional community survey of malaria infection was carried out in Agbowa and Ikosi communities in Lagos State. Finger-prick blood was used to assess the performance of three BIOCREDIT® kits: Kit 1 (PfpLDH), Kit 2 (PfLDH/HRP2), and Kit 3 (PfLDH/PvLDH). Malaria microscopy and a reference mRDT (SD BIOLINE® PfHRP2) were used as comparators. Heat stability testing was performed using Plasmodium falciparum panels after exposure to 35oC and 45oC for 60 days. A total of 834 participants were recruited.

Results: The sensitivity of BIOCREDIT® kits were: Kit 1 (PfLDH) 88.4%; Kit 2 PfHRP2 92% and PfLDH 86.6%; Kit 3 (PfLDH) 88.4%. The specificity of kits was: Kit 1 (Pf LDH) 91.7%; Kit 2 (PfHRP2) 82.3%) and (PfLDH) 92.1%; Kit 3 (PfLDH) 91.6%. The sensitivity and specificity of the reference kit were 92.9% and 85.9%. The three BIOCREDIT® Kits were stable. No potential case of pfhrp2 gene deletion was observed.

Conclusions: The sensitivities of the three BIOCREDIT® malaria test kits were similar to the reference kit (SD BIOLINE mRDT). However, the specificities of PfLDH kits were significantly higher than the specificities of PfHRP2 kits. The BIOCREDIT® kits are suitable to be deployed in malaria-endemic tropical regions.