Modelling the effects of seasonality and socioeconomic impact on the transmission of Rift Valley fever virus

PLoS Neglected Tropical Diseases
By: , and 

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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).

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Modelling the effects of seasonality and socioeconomic impact on the transmission of Rift Valley fever virus
Series title PLoS Neglected Tropical Diseases
DOI 10.1371/journal.pntd.0003388
Volume 9
Issue 1
Year Published 2015
Language English
Publisher PLOS
Contributing office(s) Wetland and Aquatic Research Center
Description e3388; 16 p.