Urban malaria in sub-Saharan Africa: a scoping review of epidemiologic studies

Malaria control in African cities faces challenges mainly due to unplanned urbanization and the spread of Anopheles stephensi. Urbanization is changing malaria dynamics, driven by environmental changes and population growth, with nearly 70% of people projected to live in urban areas by 2050. This scoping review maps the epidemiology of urban malaria in sub-Saharan Africa, identifying research gaps and guiding strategies for control and elimination.

A structured search across multiple databases was performed using predefined eligibility criteria to select articles. Accordingly, PubMed, Medline EBSCO, Google scholar, Science direct, Cochrane library and grey literature sources were searched for relevant articles. The Joanna Briggs Institute (JBI) guidelines were followed for evidence selection, data extraction, and presentation of findings. Peer-reviewed and gray literature published in English after 2014 that reported on the prevalence, incidence, or risk factors of urban malaria in sub-Saharan Africa was included in the review.

Of the 2459 records identified from various databases, 32 articles were selected for review. A majority of those reviewed studies were community-based studies conducted in urban settings of sub-Saharan African countries. This review found the prevalence of malaria between 0.06% and 58%. This heterogeneity in prevalence is due to differences in diagnostic methods, study design, population characteristics, diagnostic methods, and environmental factors. A majority of those reviewed studies reported the prevalence between 10 and 30% with Plasmodium falciparum and Plasmodium vivax the dominant species. The review identified key factors associated with urban malaria infection, including socioeconomic status, travel history, prior infection, proximity to water sources, availability of vegetation in the compound, temperature, humidity, livestock ownership, and ITN utilization.

This review found a high prevalence of urban malaria infection in sub-Saharan Africa and there was regional variation. Sociodemographic and socioeconomic status, travel history, ITN utilization, previous history of malaria infection and environmental factors like proximity to water sources, presence of vegetation, temperature, humidity, and livestock ownership were identified as factors associated with urban malaria infection. Hence, there is a need for a comprehensive approach to control urban malaria, including environmental management, improved diagnostics and treatment, socio-economic interventions, and better urban planning.