Urban Malaria in Imo State, Nigeria: Prevalence, Spatial Distribution, Demographic Determinants, and Diagnostic Performance in Three Senatorial Zones

Abstract

Malaria remains a major public health concern in Nigeria, including urban settings where its burden is often underestimated. This study assessed the prevalence and demographic determinants of malaria in three urban zones of Imo State—Orlu, Owerri, and Okigwe. A cross-sectional survey involving 400 participants was conducted between January and March 2024. Venous blood samples were analyzed using both rapid diagnostic tests (RDTs) and Giemsa-stained microscopy. Data were categorized and analyzed by age, sex, occupation, and parasite density. Microscopy confirmed an overall prevalence of 34.5%, with Orlu recording the highest rate (38.0%) and Okigwe the lowest (30.0%). Children aged 0–10 years were the most affected group (52.8%), and parasite densities ranged from 1,000 to 7,000/μL, indicating moderate infection levels. Females exhibited a slightly higher prevalence (35.0%) than males (33.9%). RDTs showed reduced sensitivity compared with microscopy, underscoring the need for accurate diagnostic tools in surveillance programs. The findings demonstrate that malaria transmission persists in urban areas of Imo State despite control efforts. Strengthening diagnostic accuracy, improving environmental management, and implementing targeted community interventions are crucial to reducing the urban malaria burden. Continuous monitoring of demographic and ecological risk factors is recommended to guide effective urban malaria control strategies.