Equine encephalosis virus (EEV): a review.

摘要

Equine Encephalosis (EE) is an arthropod borne febrile non contagious disease of equines. The causative virus, Equine encephalosis virus (EEV), has several serotypes (EEV1-EEV7) and the virus has been reported from southern Africa including Kenya, Botswana and South Africa. EEV was first isolated in 1967 from horses in the Republic of South Africa. Like the African horse sickness virus (AHSV) EEV is also endemic in southern Africa. In most of the country, EE virus in comparison to AHSV has a higher transmission rate. Two species in the Culicoides imicola species complex, C. imicola (senso stricto) and C. bolitinos are known to transmit EEV. Zebra and elephants can act as maintenance host of the virus, making the elimination of the virus difficult. Outbreaks of EEV infection is reported to be associated with equine foetus abortion during the first 5-6 months of gestation. 32P-labelled genomic probes of EEV are used for detection of viral Ribonucleic Acid (RNA). Sero-epidemiological tools for the detection of antibodies against EEV include Serum Neutralization Test (SNT) and Enzyme Linked Immunosorbent Assay (ELISA). A novel real time Polymerase Chain Reaction (PCR) assay has also been developed for the detection of EEV by targeting the gene Viral Protein (VP)-7. There is no specific treatment or vaccine available for this virus. Supportive treatment can only be provided. Management of horses in the stable is the key to control the spread of EEV in equines along with follow up of good biosecurity measures. The present review deals with all these aspects of the infection caused by this virus to enrich knowledge of researchers and equine/stud farm owners and the industry.