Optimal mitigation strategies for epidemics
Ling Xue, Caterina Scoglio, Morgan Scott, Lee Cohnstaedt.
Rift Valley Fever virus (RVFv) has been expanding its geographical distribution with important implications for both human and animal health. The emergence of Rift Valley Fever (RVF) in the Middle East, and its continuing presence in many areas of Africa, has negatively impacted both medical and veterinary morbidity, mortality, and economic endpoints. Furthermore, worldwide attention should be directed towards the broader infection dynamics of RVFv, since suitable host, vector and environmental conditions for additional epidemics likely exist on other continents; including Asia, Europe and the Americas. We propose a new compartmentalized ordinary differential equation model of RVF to assess disease spread in both time and in space; with the latter driven as a function of contact networks. Humans and livestock hosts and two species of vector mosquitoes are included in the model. The model is based on weighted contact networks, where nodes of the networks represent geographical regions and the weights represent the level of contact between regional pairings for each set of species. The inclusion of specifics on human, animal, and vector movements among regions is new to modeling RVF. The movement of the infected individuals is not only treated as a possibility, but also an actuality that can be incorporated into the model. We have tested, calibrated, and evaluated the model using data from the recent 2010 RVF outbreak in South Africa as case study; mapping the epidemic spread within and among three South African provinces. An extensive set of simulation results shows the potential of the proposed approach for accurately modeling the RVF spreading process in additional regions of the world. The benefits of our proposed model are twofold: not only can our model differentiate the maximum number of infected individuals among different provinces, but also it can reproduce the different starting times of the outbreak in multiple locations.
Presentations & Publications
L. Xue, C. Scoglio. The network level reproduction number for infectious diseases with both vertical and horizontal transmission. 2013. Accepted by Mathematical Biosciences
L. Xue, L. W. Cohnstaedt, H. M. Scott, C. Scoglio. A hierarchical network approach for modeling Rift Valley fever epidemics. Under revision
L. Xue, H. M. Scott, L. W. Cohnstaedt, C. Scoglio. A network-based meta-population approach to model Rift Valley fever epidemics. Journal of Theoretical Biology, Volume 306, Pages 129–144, 2012