141st APHA Annual Meeting and Exposition

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Online Program

292745
Modeling of potential mechanism promoting rift-valley fever epizootics in Egypt: Implications for control strategies


Monday, November 4, 2013 : 11:30 a.m. - 11:45 a.m.

Harold Gil, MSPH, Department of Epidemiology and Public Health, University of Miami, Miller School of Medicine, Miami, FL
Chris Cosner, PhD, Department of Mathematics, University of Miami, Coral Gables, FL
John Beier, ScD, Department of Epidemiology and Public Health, University of Miami, Miller School of Medicine, Coral Gables, FL
Don DeAngelis, PhD, Department of Biology, University of Miami, Coral Gables, FL
Ali Hassan, PhD, Institute of Environmental Studies and Research, Ain Shams University, Cairo, Egypt
Purpose: Rift Valley Fever (RVF) is a mosquito-borne viral zoonosis that is prevalent in Africa and parts of the Middle East. RVF epizootics among livestock can cost countries of agriculture-based economies millions of dollars in economic losses, as well as claim human lives. Identifying and understanding mechanisms driving the onset of RVF epizootics is essential to planning control and prevention measures. In Egypt, RVF epizootics have been observed to occur sporadically; the mechanism behind this behavior remains unknown. This study proposes a mechanism to explain this system behavior.

Methods: A mathematical system of equations describing disease dynamics in populations of livestock and mosquitoes in three areas (Sudan, the Nile, and Nile Delta) was constructed and explored computationally. In the model, livestock flow from RVF-endemic Sudan, through the Nile, to the Nile Delta. Hydrological data spanning a thirty-year period (August 1975-July 2005) is used to model mosquito densities of each area through time. We will apply sensitivity analyses to determine what system parameters are most important (and amenable to control).

Results: Our models suggest that the interactions between the timing and magnitudes of livestock input and mosquito densities are crucial in the development of RVF epizootics in Egypt. Simultaneity of high livestock input and mosquito densities promotes RVF epizootics where infected livestock numbers are proportional to livestock input.

Conclusions: Enforcing border control measures to prevent illegal livestock-importation at times when environmental factors are expected to promote mosquito growth might be a feasible way of controlling and preventing RVF epizootics in Egypt.

Learning Areas:

Environmental health sciences
Systems thinking models (conceptual and theoretical models), applications related to public health

Learning Objectives:
Describe the features of a mathematical and computational model of Rift-Valley Fever disease dynamics in populations of livestock and mosquitoes in three areas (Sudan, the Nile, and Nile Delta) that explains the sporadic occurrence of RVF epizootics in Egypt. Formulate recommendations to mitigate the magnitude and frequency of Rift-Valley Fever epizootics in Egypt.

Keyword(s): Zoonoses, International Health

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am the lead investigator of this project, which I have been working for the past year on. I am currently an MSPH student with interests in applying mathematical and computational skills to solving public health problems.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.

Back to: 3151.0: Malaria and emerging infectious diseases I