Climate-Driven Intraseasonal Variations in Malaria Transmission Potential Over Africa: K Malaria Index Approach

Abstract Malaria transmission is influenced by temperature and rainfall, which governs the life cycles of the Anopheles mosquito vector and the Plasmodium parasite. Intraseasonal climate fluctuations over 30–90 days can significantly alter vector and parasite development rates, influencing transmission dynamics. The K Malaria Index (KMI) integrates temperature and precipitation into a single metric to assess short-term malaria transmission potential, providing spatially and temporally detailed projections. This study addresses the gap in understanding intraseasonal climate variability's impact on malaria transmission by introducing the KMI, a novel tool for precise, short-term outbreak prediction and management in Africa. High-resolution climate data from the Coupled Model Intercomparison Project Phase 6 (CMIP6) ensemble was used to calculate the KMI under various scenarios. Results reveal that intraseasonal oscillations in rainfall and temperature directly affect mosquito survival and parasite development, creating localized transmission surges. These insights enable early-warning systems to predict outbreaks and guide interventions, such as the distribution of insecticide-treated nets (ITNs) and indoor residual spraying (IRS). The study highlights how climate change may expand malaria-prone areas, particularly in highlands previously unsuitable for transmission. By addressing the short-term variability in malaria dynamics, the KMI framework provides a foundation for climate-responsive malaria control strategies. This shows the importance of integrating climate data into health systems to enhance public health preparedness and resilience in malaria-endemic regions. This approach highlights the necessity of climate adaptation measures to mitigate the long-term impacts of climate variability and change on malaria transmission.