Assessment of the diagnostic performance of the SD Bioline Malaria antigen test for the diagnosis of malaria in the Tombel health district, Southwest region of Cameroon

Malaria rapid diagnostic tests (mRDTs) are commonly used for the diagnosis of malaria in resource-limited settings. However, the sensitivity of RDTs may vary depending on the brand. The aim of this study was to assess the diagnostic performance the SD Bioline Malaria Plasmodium falciparum antigen rapid diagnostic test (Ag P.f RDT) for the diagnosis of malaria in the Tombel Health District (THD). This was a cross-sectional community-based study targeting persons living within the THD from 30th April to 20th June 2023. A consecutive sampling technique was used to collect blood samples among 250 symptomatic and asymptomatic individuals and tested using the SD Bioline Malaria Ag P.f RDT and microscopy. Data was analysed using SPSS version 25.0. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated to assess the diagnostic accuracy of the RDT. Microscopy identified 133 (53.2%) symptomatic and asymptomatic participants with malaria and the mRDT identified 60 (24%) cases with 52 (20.8%) low parasites density and 8 (3.2%) moderate parasites density. The sensitivity of Malaria Ag P.f RDT was 45.0%, the test correctly identified 60 (45%) of true positive P. falciparium cases. The specificity of 100% showed that the test correctly identified all negative cases. PPV was 100%, there is a very high likelihood that all the positive cases are truly infected. The lower NPV of 61.5%, there is still a chance the negative cases might be infected. The Area Under the Curver (AUC) = 0.78 with moderate diagnostic suggesting that there is 22% chance that the test can produce a false positive result. The overall accuracy of mRDT in the THA is moderate. This level of accuracy may be acceptable in some contexts, but it is not ideal for a screening test, particularly for a disease like malaria that can have serious health consequences if left untreated.