Climate-driven intraseasonal variations in malaria transmission potential across Africa: K Malaria Index approach

This study explores the connection between key meteorological variables and malaria incidence across Africa, addressing a critical gap in understanding how climate patterns influence disease persistence. Employing Climatic Research Unit gridded time series (CRU_TS) climate data (1981-2024), we established the K Malaria Index (KMI), an integrated quantity of climatic suitability for Plasmodium falciparum transmission based on a temperature-dependent extrinsic incubation period (EIP) and rainfall thresholds for mosquito breeding. Spatial analysis showed that regions with mean temperatures >18°C and monthly rainfall ≥80 mm, predominantly in Central, West, and parts of East Africa, have the highest and most persistent transmission suitability. A significant long-term warming trend (+0.14°C decade -1 ) links with a shortening of the EIP, enhancing transmission potential. Time-series validation shows that the KMI and its component variables have significant positive correlations with past malaria mortality rates, confirming its advantage as a predictive tool. The findings highlight the necessity of incorporating climate forecasts into public health planning to build effective and robust malaria control strategies under global warming.