Epizootic Hemorrhagic Disease Virus: Current Knowledge and Emerging Perspectives

Abstract

Epizootic Hemorrhagic Disease (EHD) of ruminants is a viral pathology that has significant welfare, social, and economic implications. The causative agent, epizootic hemorrhagic disease virus (EHDV), belongs to the Orbivirus genus and leads to significant regional disease outbreaks among livestock and wildlife in North America, Asia, Africa, and Oceania, causing significant morbidity and mortality. During the past decade, this viral disease has become a real threat for countries of the Mediterranean basin, with the recent occurrence of several important outbreaks in livestock. Moreover, the European Union registered the first cases of EHDV ever detected within its territory. Competent vectors involved in viral transmission, Culicoides midges, are expanding its distribution, conceivably due to global climate change. Therefore, livestock and wild ruminants around the globe are at risk for this serious disease. This review provides an overview of current knowledge about EHDV, including changes of distribution and virulence, an examination of different animal models of disease, and a discussion about potential treatments to control the disease.

Isolation of Epizootic Hemorrhagic Disease Virus Serotype 10 from Culicoides tainanus and Associated Infections in Livestock in Yunnan, China

“…The occurrence, prevalence, and geographical distribution of this disease are intricately linked to the species and geographical spread of its primary transmission vector, Culicoides [ 3 ]. Current research highlights C. obsoletus , C. actoni , C. brevitarsis , C. imicola , and C. oxystoma as the primary vectors or potential carriers of EHDV [ 38 , 39 ]. In this study, two strains of EHDV-10 were successfully isolated from C. tainanus collected from cattle pens in Jiangcheng.…”

“…EHD is a global concern, with notable regions of prevalence spanning North America, Africa, Australia, and Asia [ 29 ]. In recent times, this disease has extended its reach into the Mediterranean Basin, affecting countries like Morocco, Algeria, Tunisia, Israel, Jordan, and Turkey [ 38 ]. This expansion demonstrates that EHDV has not only established a wide geographical presence but continues to broaden its scope.…”

The Molecular Epidemiology of Epizootic Hemorrhagic Disease Viruses Identified in Israel between 2015 and 2023

“…Like BTV, the primary determinant of serotype specificity is the outer capsid VP2 protein [7]. There are seven officially determined serotypes [8] and at least three putative strains representing new EHDV serotypes [9][10][11].…”

Epidemiological Analyses of the First Incursion of the Epizootic Hemorrhagic Disease Virus Serotype 8 in Tunisia, 2021–2022

“…Since then, the virus has also been detected in Canada and Mexico, as well as in other parts of the world: South America, Africa, the Middle East, Japan, Southeast Asia, and Australia [ 3 ]. To date, seven serotypes of EHDV have been reported, named 1–2 and 4–8, which were identified based on phylogenetic studies, sequencing data, and cross-neutralization assays [ 4 ]. Genetic analyses demonstrated that the previously identified serotype 3 (Nigerian strain IbAr 22619) was serotype 1 [ 5 ].…”