Epidemiological profile and environmental determinants of Plasmodium falciparum infection in villages surrounding the Soum Agropole, Burkina Faso

Background: Building dams and irrigation schemes as resilience measures against growing food insecurity and water scarcity may increase malaria risk in endemic settings. This study aims to assess the clinical and asymptomatic carriage of Plasmodium falciparum throughout the year and explores their association with socio-economic and weather factors in Nanoro, Burkina Faso. Methods: A monthly household-based surveys were conducted from March 2022 to February 2023 in five villages located at variable distance (3–40 km) from the Soum dam located in the Nanoro Health district catchment area. Socio-demographic, weather, and economic data were collected using a standardized questionnaire. Capillary blood samples were analyzed for P. falciparum infection by microscopy. A mixed-effects logistic regression model adjusted for socio-economic and environmental factors was used to assess the infection probability and to analyze how village-level and month-level factors contributed to the malaria infection risk. Results: A total of 13,786 participants were included. The overall prevalence of asymptomatic carriage (24.5%) was higher than clinical cases (19.5%). The 12-month malaria prevalence (clinical cases and asymptomatic carriage) were 39.6% (95%CI 38.79–40.42) with the highest rate (42.1% with 95% CI 40.7–43.47) reported from Soum near the dam and lowest rate (33.2%;95% CI 31.21–35.32) from Séguédin located far from the dam. Regardless of village location and transmission period, participants aged 5–19 years old had the highest prevalence of malaria infection with values ranged from 43.6% (95% CI 38.34–49.01) in Séguédin to 69.4% (95% CI 64.94–73.57) in Soum. Monthly rainfall measured in millimeters, was unexpectedly associated with decreased risk of malaria infection (OR = 0.77, 95%CI 0.66–0.9). Conclusion: The risk of malaria infection was higher in villages close to the dam, with Soum having the highest prevalence and Séguédin the lowest. This study highlights the impact of dam construction on the epidemiological profile of malaria and underscores the need for multi-sectoral approaches integrating health, water management, and socio-economic interventions to tackle the risk of the disease occurrence.