Background: Malaria in under-five children is a significant public health problem in sub- Saharan African countries with unprecedented mortality and morbidity. In Sierra Leone, the disease accounts for fourteen percent of under-five mortality and 95% of the population is at risk. The purpose of this study is to examine the relationship between malaria status in under-five children and household demographic, socioeconomic, and environmental risk factors potentially associated with the disease and to compare the test performance of rapid diagnostic test kit.

Methods: The study used cross-sectional data from the 2016 Sierra Leone Malaria Indicator Survey, which selected a nationally representative sample of 6,720 households in 336 clusters. Children aged 6–59 months in the selected households were tested for malaria using the rapid diagnostic test (RDT) and microscopy. Data were analyzed using descriptive statistics, bivariate and multivariate logistic regressions to identify risk factors associated with malaria at a 5% level of significance.

Results: The overall prevalence of malaria in under-five children was 52.67% and 40.05% using RDT and microscopy methods, respectively. RDT method was more sensitive than specific (85.52% vs. 69.23%, p<0.0001). The odds of malaria infection were significantly higher among older children aged 48–59 months (aOR= 3.28, CI: 2.61-4.13, p<0.0001), and children in the lowest wealth quintile (aOR= 5.47, CI: 2.89-10.37, p<0.0001). Other risk factors of malaria infection include children whose mothers/caregivers have attained primary educational level (aOR= 1.35, CI: 1.00-1.82, p<0.05), children living in houses built with unimproved wall materials (aOR= 0.79, CI: 0.64-0.97, p<0.05).

Conclusion: The findings of this study suggest that demographic and socioeconomic factors like age, wealth quintile and educational levels of mothers/caregivers were predictors of malaria in under-five children in Sierra Leone.