Abstract

Rift Valley Fever (RVF) is an emerging, mosquito-borne disease with serious economical and negative implications on human and animal health. This study was conducted to verify the factors which influenced the spatial pattern of Rift Valley Fever occurrence and identified the high risk areas for the occurrence of the disease at Sinner State, Sudan. The normalized difference vegetation index (NDVI) derived from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite and rainfall data in addition to the point data of RVF clinical cases in humans were used in this study. In order to identify the RVF high risk areas, remote sensing data and rainfall data were integrated in a GIS with other information including, soil type, water body, DEM (Digital Elevation Model), and animal routes and analyzed using Spatial Analysis tools. The information on clinical cases was used for verification. The Normalized Difference Vegetation Index (NDVI) was used to describe vegetation patterns of the study area by calculating the mean NDVI. The results of the study showed that, RVF risk increased with the increase in vegetation cover (high NDVI values), and increase in rainfall, which both provided suitable conditions for disease vectors breeding and a good indicator for RVF epizootics. The study concluded that, identification of high risk area for RVF disease improved the understanding of the spatial distribution of the disease and helped in locating the areas where disease was likely to be endemic and therefore preparedness measures should be taken. The identification represents the first step of prospective predictions of RVF outbreaks and provides a baseline for improved early warning, control, response planning, and mitigation. Further detailed studies are recommended in this domain.

Highlights

  • Rift Valley Fever (RVF) is an acute and febrile viral Zoonotic disease caused by a virus, which belongs to the family Bunyaviridae and the genus Phlebovirus [1]

  • The aim of the study was to identify the environmental risk factors associated with RVF disease, to investigate factors that influenced the spatial pattern of RVF during year 2007 outbreak, and to produce RVF disease risk map

  • The materials used in this study include human cases of RVF data collected from the site of infection by weekly reports; reporting human clinical cases depending on the description of case definition of RVF case

Read more

Summary

Introduction

Rift Valley Fever (RVF) is an acute and febrile viral Zoonotic disease caused by a virus, which belongs to the family Bunyaviridae and the genus Phlebovirus [1]. RVF is a serious disease with serious financial, economic, social and public health implications. In this regard, RVF affects the livestock trade according to the international list of the Office of Epidemiology. Humans acquire RVF through bites by infective mosquitoes or, more frequently, through exposure to virus contaminated blood, body fluids, or tissues of animals that have been bitten by infected mosquitoes. Direct infection of animals can occur during exposure of slaughter live or through veterinary and obstetric procedures. Outbreaks in Livestock can occur following heavy rainfall and flood that result in hatching of Aedes (Stegomyia) mosquitoes eggs which are usually existing in the cracks and holes in the ground (thought to be the initial vector and inter-epizootic reservoir of RVF). First outbreak RVF disease was reported in Sudan during June to December 1973: extensive epizootic involving sheep, goats and cattle in Kosti (White Nile), Eldueim and Sinner and as well informal reports of human cases

Objectives
Methods
Results
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call