A NEW TEST TO IDENTIFY EPIZOOTIC HAEMORRHAGIC DISEASE IN DROMEDARIES

Epizootic haemorrhagic disease of deer (EHD), caused by a virus transmitted by the bite of insects of the genus Culicoides, was first identified in 1955 during an epidemic that seriously affected a species of deer native to North America. In these animals, from which it took its original name, the disease can be very serious, leading to death in a large percentage of cases. In the years after its first appearance, other species of ruminants, both wild and domestic such as sheep and cattle, were discovered to be affected. While the former, despite being carriers, do not develop important clinical signs, cattle can fall ill, with an impact on milk production and on the entire breeding system in general. The disease is currently endemic in North America and has caused several outbreaks also in ruminants in Africa, Australia, the Middle East and Asia. In 2006, outbreaks were found in North Africa (Tunisia, Algeria and Morocco).

Due to the high prevalence of EHD in the Mediterranean basin, detection strategies for the responsible virus (EDHV) are particularly urgent and important. A contribution in this field comes from a research carried out by the Viral Vaccines and Diagnostics Production Department of the Istituto Zooprofilattico Sperimentale di Teramo (IZSAM). The study, published in the Journal of Tropical Medicine, has been awarded by the Italian Society of Veterinary Laboratory Diagnostics in the course of its twentieth National Congress.

First of all, researchers produced in laboratory, using recombinant technology, a specific viral protein of the Epizootic Hemorrhagic Disease virus (named VP7). The protein was then used for the realization of an ELISA test (identifying antigen-antibody reaction). “Dromedaries – says Simonetta Ulisse, of the Viral Vaccines and Diagnostics Production Department–do not seem to develop clinical signs of the disease, but they can become infected, potentially playing a role in the spread of EHD. The hypothesis is that they could act like sentinels, useful for monitoring the presence of the disease in a certain territory".

With dromedaries, attention focuses on Africa, a potential gateway to Europe. "Our test - explains Anna Serroni, from the Viral Vaccines and Diagnostics Production Department - proved to be very effective not only in detecting the presence of specific antibodies against the EHD virus in the serum of dromedaries, but also in discriminating this virus from other, very similar, ones, such as Bluetongue or African horse sickness. Therefore, it could be a new tool for the rapid identification of EHD in order to help surveillance and prevention interventions, even in areas not currently affected".

DEVELOPMENT OF A COMPETITIVE ENZYME-LINKED IMMUNOSORBENT ASSAY BASED ON PURIFIED RECOMBINANT VIRAL PROTEIN 7 FOR SEROLOGICAL DIAGNOSIS OF EPIZOOTIC HAEMORRHAGIC DISEASE IN CAMELS

Serroni A, Ulisse S, Iorio M, Laguardia C, Testa L, Armillotta G, Caporale M, Salini R, Lelli D, Wernery U, Raghavan R, Mercante MT, Di Ventura M. Development of a Competitive Enzyme-Linked Immunosorbent Assay Based on Purified Recombinant Viral Protein 7 for Serological Diagnosis of Epizootic Haemorrhagic Disease in Camels. J Trop Med. 2022 Mar 21;2022:5210771. doi: 10.1155/2022/5210771. PMID: 35356489; PMCID: PMC8959998.

https://doi.org/10.1155/2022/5210771