Use of the serum neutralisation test for equine viral arteritis with different virus strains.

The research paper reports that the blood serum test for equine viral arteritis using different virus strains has been successful in identifying infected horses, with the modified Bucyrus strain showing high neutralisation rates amongst tested equine serum samples.

Research Methodology

• The team carried out serum cross-neutralisation tests using different strains of the equine arteritis virus. This included a recent American isolate (84KY-A1), a European isolate (Wroclaw-2), and the prototype and modified versions of the Bucyrus strain.
• These different virus strains were exposed to virus-specific immune horse serum for the test.

Results and Findings

• The modified Bucyrus strain was found to be neutralised by the immune horse sera, demonstrating high neutralisation titres with all tested sera.
• The prototype Bucyrus strain was largely neutralised, with the 84KY-A1 strain following suit.
• Using the modified Bucyrus strain as the antigen, the researchers identified 20 seropositive horses amongst home-bred horses that had no history of clinical equine viral arteritis.
• Heat inactivation of the sera at 62 degrees C for 30 minutes led to the disappearance of all but the most positive reactions.
• When the prototype Bucyrus strain was used as the antigen instead of the modified one, no positive reactions were noted.

Serological Survey

• A serological survey was also conducted using the Bucyrus strain in a microtitre neutralisation test.
• 1656 horse sera samples collected from 1988-1990 in Japan were used in this survey.
• The survey identified only eight foreign-bred horses that reacted positively to the virus. Interestingly, these horses were imported for competition purposes.
• However, the researchers found no evidence to suggest that these foreign-bred horses were a source of infection for local horse populations that were virus-free.