Equine viral arteritis. Current status in Finland.

This research article presents an investigation of antibodies against equine arteritis virus (EAV) in Finland’s horse population conducted in 1996, which includes imported horses and isolated gene sequencing from local horse semen. This analysis was done to understand the presence and genetic relationships of the virus within Finland and compare it to other global strains.

Objective and Methodology

• The study aimed to assess the presence and characterise the equine arteritis virus (EAV) in Finland’s horse population during 1996 using serological analysis (analysis of the blood serum to detect antibodies).
• All horse sera that were delivered to Virology Unit at the National Veterinary and Food Research Institute at that time were utilised for the purpose of the research.
• The study included imported horses to evaluate EAV circulation in other countries. This helped the researchers understand the international landscape of the virus’s spread and its bearing on the Finnish horse population.
• To detect the presence of the virus, researchers used a micro-neutralization test which involves neutralising the virus in a lab environment using the Arvac strain as an antigen. The antigen is a substance that triggers an immune response, and here it was used to induce the presence of antibodies for confirmation of the virus.

Results and Findings

• Nucleocapsid gene sequences, which are a part of the virus’s genetic makeup, were isolated from Finnish horse semen samples. The researchers used reverse transcription-polymerase chain reaction (RT-PCR), a common method for detecting the presence of specific genetic materials in any pathogen, including viruses. By amplifying these sequences, they were able to study them closely.
• The research led to sequencing and subsequent genetic analysis that allowed the researchers to compare these sequences to those isolated elsewhere in the world, enabling an understanding of their genetic relationships.
• The isolates from Finland were found to bear a high nucleotide identity (98.2%), implying that the strains of the virus prevalent in Finland were quite similar to each other.
• Interestingly, the strains found in the Finnish horses were most closely related to those isolated from Norwegian horse semen in 1988 and 1989. This finding can be instrumental in tracing the transmission and spread of the virus across borders and over the years.