Background A detailed understanding of the contribution of the asymptomatic Plasmodium reservoir to the occurrence of clinical malaria at individual and community levels is needed to guide effective elimination interventions. This study investigated the relationship between asymptomatic P. falciparum carriage and subsequent clinical malaria episodes in Dielmo and Ndiop villages in Senegal. Methods The study used a total of 2,792 venous and capillary blood samples obtained from asymptomatic individuals and clinical malaria datasets collected from 2013 to 2016. Mapping, spatial clustering of infections and risk analysis were performed using georeferenced households. Results High incidences of clinical malaria episodes were observed to occur predominantly in households of asymptomatic P. falciparum carriers. A statistically significant association was found between asymptomatic carriage in a household and subsequent episode of clinical malaria occurring in that household for each individual year (p-values were 0.0017, 6x10 -5, 0.005, and 0.008 for 2013, 2014, 2015, and 2016 respectively) and the combined years (p=8.5x10 -8), which was not found at the individual level. In both villages, no significant patterns of spatial clustering of P. falciparum clinical cases was found, but there was a higher risk of clinical episodes <25m from asymptomatic individuals in Ndiop attributable to clustering within households. Conclusion The findings provide strong epidemiological evidence linking the asymptomatic P. falciparum reservoir to clinical malaria episodes at household scale in Dielmo and Ndiop villagers. This argues for a likely success of a mass testing and treatment intervention to move towards the elimination of malaria in Dielmo and Ndiop villages.

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