Seroprevalence study of Equine rhinitis B virus (ERBV) in Australian weanling horses using serotype-specific ERBV enzyme-linked immunosorbent assays.

This research examines the rate at which horses in Australia carry the Equine rhinitis B virus (ERBV), a common cause of respiratory disease in horses. Using newly developed ELISA tests that are serotype-specific, the study revealed that most horses carried at least one serotype of ERBV, with almost 60% of horses testing positive for the ERBV-3 serotype.

Equine Rhinitis B Virus (ERBV) and Its Impact

• Equine rhinitis B virus (ERBV) is known to cause respiratory infections in horses, significantly impacting their performance. This makes it a significant concern in the horse industry.
• Previous studies have indicated that between 50-80% of horses tested have ERBV-neutralizing antibodies, suggesting prior exposure to ERBV.
• Existing tests for ERBV may not capture the full scope of its prevalence, as they may not identify instances where horses are infected with multiple ERBV serotypes.

Objective of the Study and Methodology

• The researchers aimed to create an ERBV antibody-detection ELISA test capable of identifying different serotypes of ERBV. This would deliver a more nuanced understanding of ERBV prevalence.
• The study focused on a group of weanling (young, recently weaned) horses in Australia to gauge the presence of ERBV.
• The ELISA tests created were high in both sensitivity (the ability to correctly identify positive cases) and specificity (the ability to correctly identify negative cases).

Findings and Implications

• The results showed a high percentage of horses (74-86%) tested positive for ERBV, indicating a high seroprevalence among the population studied.
• ERBV-3 antibodies were the most prevalent, found in 58-62% of horses. In contrast, ERBV-2 antibodies were found in merely 10-16% of horses. These findings could have implications for understanding which ERBV serotypes are most common.
• A significant number of horses tested positive for more than one serotype, illustrating the importance of tests that can identify multiple serotypes.