Rift Valley Fever
Through an integrative new approach with scientific, methodological and technical issues, consortium S2E will open by the deep analysis of Health Environment relationships a new field for early warning operational systems able to alert and predict the geographical extension of epidemics.
The integrative approach consists in three main objectives :
Deployment of ground Health Information Systems (epidemiological networks) for data early waring, information transfer and management in real time.
Use of bio-mathematical modelling of epidemic phenomena dynamics ( quantitative approach of risk), which integrates transportation processes, pathogens, vectors, hosts and physical & socio-ecological environment.
Remote sensing approach (environmental approach), which measures epidemics cofactors as vegetation, hydrology, forest, coverage, meteorology, population .
The first ground based survey entitled the EMERCASE programme started in July 2000 in the Senegal River Valley. The Rift Valley Fever surveillance network associates local research team and public health services as well as local administrations in charge of environment management of Senegal & Mauritania
Rift valley Fever (RVF) is an infectious disease caused by an arbovirus of the genus Phlebovirus of the family Bunyaviridae. Primarily spread amongst animals (mainly bites from infected mosquitoes), the RVF virus can infect humans through contact with blood, body fluids or organs during care or slaughter of infected animals. The virus may be transmitted by other biting insects (see Weiss, 1957 ; Meegan and Bailey, 1988 ; IEMVT-CIRAD, 1990 ; Prehaud and Bouloy, 1997 ; Lefevre, 1997 ; (...)(read more...)
RVF-like disease early in 1912-1913 near Lake Naivasha (Great Rift Valley) in Kenya was described by Montgomery and Stordy. But it was later in 1931 that the RVF virus was first isolated during a epizooty in the same area.
In East Africa, RVF outbreaks were known to follow periods of abnormally high rainfall ( Linthicum and al., 1999). Outbreaks has since occurred in many other African countries, pretty much associated with climate disorder or environment change.
Evidence of RVF virus (...)
Incidence of climate and environment on human health is well-known. Local climate conditions have biological implications on some diseases vectors and can modulate the Extrinsic Incubation Period (EIP) of vectors as well as behavior of pathogenic agents.
Satellites monitoring from space agencies such as CNES, CONAE, and NASA among others, with derived added-values products and analyses, can help providing real-time climate and environment variability possibly linked to epidemics’ risks. (...)
Anomalous climatic conditions are recognized to be linked with outbreaks of various human and livestock diseases in various countries (Nicholls, 1991 ).
Vegetation in semi-arid and arid regions responds quickly to rainfall, and anomalous landcover conditions can be quickly mapped over large areas. For example indices such as the normalized difference vegetation index (NDVI) can been obtained rapidly in order to identify regions where conditions are suitable for the development of RVF (...)