The impact of climate change on the epidemiology and control of Rift Valley fever.

Climate change is likely to change the frequency of extreme weather events, such as tropical cyclones, floods, droughts and hurricanes, and may destabilise and weaken the ecosystem services upon which human society depends. Climate change is also expected to affect animal, human and plant health via indirect pathways: it is likely that the geography of infectious diseases and pests will be altered, including the distribution of vector-borne diseases, such as Rift Valley fever, yellow fever, malaria and dengue, which are highly sensitive to climatic conditions. Extreme weather events might then create the necessary conditions for Rift Valley fever to expand its geographical range northwards and cross the Mediterranean and Arabian seas, with an unexpected impact on the animal and human health of newly affected countries. Strengthening global, regional and national early warning systems is crucial, as are co-ordinated research programmes and subsequent prevention and intervention measures.