| Abstract: |
| Ebola virus disease (EVD) is an overwhelming haemorrhagic fever causing serious threats to human health, with outbreaks frequently linked to a spillover from wildlife reservoirs. Climatic factors are suspected to influence EVD transmission. However, the mechanisms by which this proceeds remain poorly understood. The aim of this talk is to quantify the effects of some climatic drivers such as temperature and rainfall on the spread of EVD. We consider direct and indirect routes of contamination between and within human and fruit bat populations, and model the transmission dynamics of the disease as a system of nonlinear ordinary differential equations, where some key climate-dependent parameters are incorporated as functions of temperature and rainfall. The nonautonomous differential system derived is completely analysed. To begin with, we neglect the intra-annual variation of climate, and investigate the corresponding autonomous system obtained. The basic reproduction number is computed, and the existence and stability of equilibria are successfully studied. Sensitivity analyses highlight, among others, the critical role of environmental transmission and cross-species contamination. Secondly, the nonautonomous model is thoroughly investigated by mainly relying on the definition of the basic reproduction number in periodic environments. We prove the existence, uniqueness and global stability of a positive Ebola-free solution. Finally, to illustrate the theoretical findings, we perform some numerical simulations using real climate data from the locality of Beni (Democratic Republic of Congo). Our results reveal that temperature and rainfall can actually influence the spread of EVD. The present investigation provides a quantitative framework linking climate change to Ebola virus ecology, and a valuable tool for public health planning in climate vulnerable regions. |
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