Human and vector behavioural determinants of malaria transmission in the Nandi highlands, western Kenya

This study demonstrates that human exposure to malaria vectors is shaped by the interplay between temporal and spatial human and vector behaviours, with the highest biting rates indoors for unprotected sleepers and awake individuals, and outdoor exposure peaking in the early evening and late morning. It also reveals diverse, behaviourally adaptable vector populations, including cryptic species, sustaining indoor and outdoor transmission. While LLINs use provide partial protection, significant gaps in protection remained during periods and in spaces where nets are not effective, highlighting persistent residual transmission and the need for vector characterization, behaviour-informed interventions (e.g., spatial repellents and larviciding), community engagement, and strengthened entomological surveillance to guide effective malaria control.