Epidemiology and genetic characterization of equine infectious anaemia virus strains isolated in Belgium in 2010.

This study investigates the epidemiology and genetic characterization of the equine infectious anaemia virus (EIA) originating from Belgium in 2010.

Study Methodology and Findings

A series of investigations and surveys were conducted based on an initial report from the UK of EIA found in two horses imported from Belgium. The researchers carried out the following procedures:

• Initially, among the additional 16 horses that were transited through Belgium alongside the infected ones, nine were further investigated. This led to the discovery of one more EIA-positive horse.
• Upon this finding, the Belgian Federal Agency for the Safety of the Food Chain (FASFC) decided to conduct a serological EIA survey on horses imported into Belgium from Romania between 2007 and 2009. The survey identified 95 horses, among which six more seropositive cases were found.
• The survey was then extended to the horses in direct contact with these positive cases. All contact animals tested negative, which indicated that there was no transmission of the virus among them.
• Finally, virological examination was performed on tissue samples collected from two seropositive animals. These examinations confirmed the presence of viral DNA of the EIA virus.

Genetic Characterization & Phylogenetic Analysis

Genetic characterization was done to provide a deeper insight into the viral strains. The researchers utilized phylogenetic analysis based on the sequences of the EIA virus gag gene. Through this:

• The Belgian viral strains were found to cluster with Romanian strains isolated in 2009.
• It was confirmed that the Belgian viral strains had a common origin that was not local to the country. This rule-out of a common Belgian origin was a significant part of their findings.

In conclusion, the research provided insights into the EIA virus strains circulating in Belgium in 2010, highlighting the importance of regular monitoring and characterization of EIA in horses, especially those imported from high-risk areas.