Performance of rapid diagnostic test, light microscopy, and polymerase chain reaction in pregnant women with asymptomatic malaria in Nigeria

Objectives: Rapid diagnostic tests (RDTs) offer an attractive tool for diagnosing malaria in pregnancy. This study assessed the effectiveness of a Plasmodium falciparum-specific specific RDT compared with microscopy and polymerase chain reaction (PCR) in diagnosing asymptomatic malaria in pregnant women in southwest Nigeria. Methods: The study included 406 asymptomatic pregnant women seeking antenatal care. Blood samples were collected and tested using RDT (SD Bioline, Standard Diagnostics Inc. Korea) and light microscopy and confirmed using nested PCR. Results: The study revealed that the malaria parasite positivity rate was 8.9% by RDT, 21% by microscopy, and 32% by nested PCR. RDT had a sensitivity of 51.4% and specificity of 69.5%, whereas microscopy had a sensitivity of 65.3% and specificity of 98.2%. The combined testing of microscopy and RDT had a sensitivity and specificity of 100%. The study also showed a high prevalence of mild anemia among participants. Conclusions: Despite the RDT's low sensitivity, its high negative predictive value suggests it could be useful in combination with microscopy in ruling out asymptomatic malaria in pregnancy. Further study will help identify more suitable RDTs for routine malaria diagnosis in Nigeria and strengthen malaria prevention programs in pregnant women.