Prevalence of serotype specific antibody to equine encephalosis virus in Thoroughbred yearlings in South Africa (1999-2004).

The research article discusses the prevalence of antibodies to equine encephalosis virus in Thoroughbred yearlings in South Africa from 1999-2004, indicating variations in infections both by time and location, with certain serotypes more common than others.

Study Overview

• This study sought to establish the frequency of specific antibodies to the equine encephalosis virus (EEV) in Thoroughbred yearlings in South Africa.
• EEV is an orbivirus that can cause mild to moderate fever, depression, and edema in equine species.
• The research was carried out over a period of six years, where yearlings were sampled annually for serotype specific antibodies to EEV.

Methodology and Results

• The study implemented a retrospective serological survey and focused on Thoroughbred stud farms in several distinct geographical regions in South Africa.
• The rates of these antibodies varied from 3.6% to 34.7% each year, pointing to the occurrence of both single and multiple serotype infections.
• Over the six-year period, serotypes 1 and 6 were the most common and widespread, while serotypes 2, 3, 4, 5, and 7 were identified as infrequent and localized, affecting only specific horses.

Significance and Applications

• This study sheds light on the regular presence of equine encephalosis virus in the Thoroughbred horse population in South Africa and the variation of infection by serotype and time.
• The findings have important implications for the management and prevention of equine encephalosis virus, particularly in the featured geographic regions.
• Also, the study serves as a model for understanding the seasonal occurrence of other orbiviruses such as African horse sickness and bluetongue in areas where these diseases are common.