Comparative evaluation of rapid diagnostic tests and microscopy for placental malaria diagnosis among primigravidae after delivery in health care centres in Kwara State, North Central, Nigeria, 2023-2024

Introduction: Malaria infection in pregnancy can lead to placental malaria, which is linked to negative pregnancy outcomes. This study aimed to evaluate different diagnostic techniques, determine the prevalence, and identify the risk factors associated with placental malaria. Methods: This hospital-based cross-sectional study was conducted between January 2023 and September 2024 in healthcare facilities in Ilorin North, Kwara State. A total of 654 consenting women participated, with placental blood samples collected at delivery. Malaria diagnosis was performed using RDTs, and Giemsa-stained blood smears were examined microscopically for malaria parasites. Descriptive statistics, chi-square tests, and calculations of sensitivity and specificity were conducted, with a significance level set at p<0.05. Results: Of the 654 participants 394 (60.24%) were positive for placental malaria by RDT and 375 (57.34%) by microscopy. Only P. falciparum was detected during this study. Blood group O+ had the highest infection at 141 (35.79%) and 135 (36.00%) by RDT and microscopy, while infection was highest among business women, 337/564 and 325/564 by RDT and microscopy. A significant association between placental malaria and blood group was identified using both RDT (χ² = 30.2, p < 0.001) and microscopy (χ² = 46.5, p < 0.001). Ethnicity also showed a significant relationship with malaria detection by microscopy (χ2=9.94, p=0.019). Besides, occupation was significantly associated with malaria positivity by microscopy (χ2=18.5, p<0.001). The diagnostic methods demonstrated good performance, with a sensitivity of 0.9976 (95% CI: 0.9930–1.0023) and a specificity of 0.9094 (95% CI: 0.8779–0.9408). Furthermore, BMI was significantly associated with a decreased likelihood of placental malaria, as higher BMI was linked to a lower risk (aOR = 0.0346, 95% CI: 0.175-0.683). Conclusion: Placental malaria prevalence in Ilorin North, Kwara State, indicates a significant burden, with younger parturients (ages 26–30) and those in outdoor occupations, such as traders, facing a higher risk. The findings showed the need for continued monitoring and targeted intervention strategies, including improved diagnostic strategies, to address placental malaria in this population.