Sero-epidemiological survey of bluetongue disease in one-humped camel (Camelus dromedarius) in Kassala State, Eastern Sudan

Molhima M Elmahi,Abdel Rahim M El Hussein,Abdel Rahim E Karrar,Amira M Elhassan,Mohammed O Hussien

doi:10.1186/s13620-021-00186-2

Abstract

BackgroundBluetongue (BT) is a vector-borne viral disease of ruminant and camelid species which is transmitted by Culicoides spp. The causative agent of BT is bluetongue virus (BTV) that belongs to genus Orbivirus of the family Reoviridae. The clinical disease is seen mainly in sheep but mostly sub-clinical infections of BT are seen in cattle, goats and camelids. The clinical reaction of camels to infection is usually not apparent. The disease is notifiable to the World Organization for Animal Health (OIE), causing great economic losses due to decreased trade and high mortality and morbidity rates associated with bluetongue outbreaks. The objective of this study was to investigate the seroprevalence of BTV in camels in Kassala State, Eastern Sudan and to identify the potential risk factors associated with the infection. A cross sectional study using a structured questionnaire survey was conducted during 2015–2016. A total of 210 serum samples were collected randomly from camels from 8 localities of Kassala State. The serum samples were screened for the presence of BTV specific immunoglobulin (IgG) antibodies using a competitive enzyme-linked immunosorbent assay (cELISA).ResultsSeropositivity to BTV IgG was detected in 165 of 210 camels’ sera accounting for a prevalence of 78.6%. Potential risk factors to BTV infection were associated with sex (OR = 0.061, p-value = 0.001) and seasonal river as water source for drinking (OR = 32.257, p-value = 0.0108).ConclusionsSex and seasonal river as water source for drinking were considered as potential risk factors for seropositivity to BTV in camels. The high prevalence of BTV in camels in Kassala State, Eastern Sudan, necessitates further epidemiological studies of BTV infection in camels and other ruminant species to better be able to control BT disease in this region.

Highlights

Bluetongue (BT) is a vector-borne viral disease of ruminant and camelid species which is transmitted by Culicoides spp
The present study aimed to provide the first serological investigation of bluetongue virus (BTV) infection and to identify potential risk factors associated with the infection among one-humped camels (Camelus dromedarius) in Kassala State, Eastern Sudan
The present study showed that water source for drinking is another potential risk factor that affects BTV seropositivity in Kassala State, with camels that drink from the seasonal river more significantly infected than camels that drink from other water sources

Summary

Introduction

Bluetongue (BT) is a vector-borne viral disease of ruminant and camelid species which is transmitted by Culicoides spp. These serotypes (1,4 and 16) were recovered from sentinel calf herds at Shambat (Khartoum) [5] The sheep breeds, such as Sudanese ecotypes of sheep, may develop clinical disease while cattle and camelids mostly develop sub-clinical infections [1]. Elhassan et al [10] reported that BTV antibodies in cattle were highly prevalent in Gazira (central Sudan), and cattle can be source of infection for Culicoides species that are biologically transmitted BTV to other ruminants. Adam et al [11] and Khair et al [12] reported that BTV existed in North Kordufan and East Darfur States in western Sudan, respectively

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