title: Modelling the effects of seasonality and socioeconomic impact on the transmission of rift valley Fever virus.
abstract: Rift Valley fever (RVF) is an important mosquito-borne viral zoonosis in Africa and the Middle East that causes human deaths and significant economic losses due to huge incidences of death and abortion among infected livestock. Outbreaks of RVF are sporadic and associated with both seasonal and socioeconomic effects. Here we propose an almost periodic three-patch model to investigate the transmission dynamics of RVF virus (RVFV) among ruminants with spatial movements. Our findings indicate that, in Northeastern Africa, human activities, including those associated with the Eid al Adha feast, along with a combination of climatic factors such as rainfall level and hydrological variations, contribute to the transmission and dispersal of the disease pathogen. Moreover, sporadic outbreaks may occur when the two events occur together: 1) abundant livestock are recruited into areas at risk from RVF due to the demand for the religious festival and 2) abundant numbers of mosquitoes emerge. These two factors have been shown to have impacts on the severity of RVF outbreaks. Our numerical results present the transmission dynamics of the disease pathogen over both short and long periods of time, particularly during the festival time. Further, we investigate the impact on patterns of disease outbreaks in each patch brought by festival- and seasonal-driven factors, such as the number of livestock imported daily, the animal transportation speed from patch to patch, and the death rate induced by ceremonial sacrifices. In addition, our simulations show that when the time for festival preparation starts earlier than usual, the risk of massive disease outbreaks rises, particularly in patch 3 (the place where the religious ceremony will be held).
authors.affiliation: Department of Mathematics, University of Miami, Coral Gables, Florida, United States of America; Department of Public Health Science, Miller School of Medicine, University of Miami, Miami, Florida, United States of America.
authors.forename: Yanyu
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: Department of Public Health Science, Miller School of Medicine, University of Miami, Miami, Florida, United States of America.
authors.forename: John C
authors.initials: JC
authors.lastname: Beier
authors.affiliation: Department of Mathematics, University of Miami, Coral Gables, Florida, United States of America.
authors.forename: Robert Stephen
authors.initials: RS
authors.lastname: Cantrell
authors.affiliation: Department of Mathematics, University of Miami, Coral Gables, Florida, United States of America.
authors.forename: Chris
authors.initials: C
authors.lastname: Cosner
authors.affiliation: U.S. Geological Survey, Department of Biology, University of Miami, Coral Gables, Florida, United States of America.
authors.forename: Donald L
authors.initials: DL
authors.lastname: DeAngelis
authors.affiliation: Department of Mathematics, University of Miami, Coral Gables, Florida, United States of America.
authors.forename: Shigui
authors.initials: S
authors.lastname: Ruan
mesh_terms: D000349:Africa / Q000453:epidemiology; D000818:Animals; D009033:Culicidae; D004196:Disease Outbreaks / Q000662:veterinary; D005260:Female; D006801:Humans; D058751:Livestock; D008954:Models, Biological; D010507:Periodicity; D011157:Population Dynamics; D012295:Rift Valley Fever / Q000191:economics / Q000453:epidemiology / Q000635:transmission* / Q000821:virology; D012296:Rift Valley fever virus / Q000502:physiology*; D012621:Seasons; D012959:Socioeconomic Factors