Remote Sensing and Public Health Issues in a Changing Climate and Environment: The Rift Valley Fever Case

Climate and environment are changing rapidly. We must then cope with new challenges posed by new and re-emerging diseases, innovate beyond benches and bedsides, i.e., using high resolution technology, and re-invent health politics and multidisciplinary management, all in a climate change context. The new concept of tele-epidemiology is presented. The detailed conceptual approach (CA) associated with Rift Valley Fever (RVF) epidemics in Senegal (monitored from space) is given. Ponds were detected by using high-resolution SPOT-5 satellite images. Data on rainfall events obtained from the Tropical Rainfall Measuring Mission (NASA/JAXA) were combined with in-situ data. Localization of vulnerable and parked hosts (from QuickBird satellite) is also used. The dynamic spatio-temporal distribution and aggressiveness of one of the main RVF vectors, Aedes vexans, were based on total rainfall amounts, pond dynamics and entomological observations. Detailed risks zones (hazards and vulnerability) are expressed in percentages of parks where animals are submitted to mosquitoes’ bites. This CA, which simply relies upon rainfall distribution evaluated from space, is meant to contribute to the implementation of an operational early warning system (EWS) for RVF or RVFews. It is based on environmental risks associated with climatic and environmental changing conditions: natural and anthropogenic. It is to be applied to other diseases and elsewhere. This is particularly true in new places where vectors have been rapidly adapting recently whilst viruses circulate from an ever moving and increasing population.