Vet World   Vol.19   February-2026  Article - 30 

Seroprevalence, risk factors, and spatial distribution of epizootic hemorrhagic disease virus in dromedary camels from northern Oman

Background and Aim: Epizootic hemorrhagic disease virus (EHDV), an Orbivirus transmitted by Culicoides midges, infects a wide range of ruminant species including dromedary camels (Camelus dromedarius). Although circulation of EHDV has been documented in cattle in the Sultanate of Oman, its epidemiology in camels remains poorly characterized. This study was conducted in the Al Batinah North and Al Batinah South governorates, coastal regions with hot, arid climates favorable to vector activity, to estimate individual-level seroprevalence of EHDV antibodies in dromedary camels, identify associated risk factors using univariate and multivariate analyses, and evaluate spatial distribution patterns to inform future control measures in multi-host livestock systems. 

Materials and Methods: A cross-sectional study was performed between September 2020 and July 2021. Serum samples were collected from 415 camels across 50 holdings using convenience sampling. Antibodies against EHDV were detected with a commercial competitive enzyme-linked immunosorbent assay (c-ELISA) targeting the VP7 protein (sensitivity = 85.9 %, specificity = 99.7 %). True prevalence (TP) was calculated using the Rogan–Gladen estimator. Univariate associations were assessed with chi-square or Fisher’s exact tests; variables with p < 0.25 were entered into backward stepwise binary logistic regression. Spatial analyses included average nearest-neighbour clustering, Getis-Ord Gi* hot-spot analysis, and kernel density estimation in ArcGIS. 

Results: Apparent seroprevalence was 40.2 % (95 % confidence interval [CI]: 35.5–45.1 %), with an estimated TP of 46.7 % (95 % CI: 41.3–52.3 %). No significant difference existed between governorates (p = 0.520). In univariate analysis, seropositivity was significantly higher in camels > 4 years of age (45.9 % vs 19.3 %; p < 0.001), in breeding/leisure camels (43.1 % vs 20.8 %; p = 0.002), and in animals kept in contact with other ruminants (49.3 % vs 35.6 %; p = 0.007). After multivariate adjustment, only age > 4 years (odds ratio [OR] = 3.4, 95 % CI: 1.88–5.96; p < 0.01) and contact with other ruminants (OR = 1.6, 95 % CI: 1.05–2.44; p = 0.029) remained independent risk factors. Global spatial clustering of positive holdings was highly significant (nearest-neighbour ratio = 0.39, z = –8.26, p < 0.001), with elevated density along coastal agricultural corridors. 

Conclusion: This first large-scale serological survey confirms active circulation of EHDV among dromedary camels in northern Oman. Older age and mixed-species herding are the main risk factors identified. The findings highlight the importance of camels in the multi-host ecology of EHDV and emphasize the need for integrated national surveillance, vector studies, and molecular characterization of circulating serotypes to support evidence-based control strategies in a changing climate. 

Keywords: dromedary camels, EHDV antibodies, epizootic hemorrhagic disease, northern Oman, risk factors EHDV, seroprevalence study, spatial clustering EHDV.

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How to cite this article: Hussain MH, Elshafie EI, Ali H, Al Habsi K, Al Toubi AG, Al-Hamrashdi A, Al-Harrasi M. Seroprevalence, risk factors, and spatial distribution of epizootic hemorrhagic disease virus in dromedary camels from northern Oman. Vet World. 2026;19(2): 877-887.

Received: 26-09-2025   Accepted: 28-01-2026   Published online: 28-02-2026

Corresponding author: Elshafie Ibrahim Elshafie and Muhammad Hammad Hussain    E-mail: eielshafie@squ.edu.om and m.hussain1@squ.edu.om

DOI: 10.14202/vetworld.2026.877-887

Copyright: Hussain, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.