Evidence of Borna disease virus genome detection in French domestic animals and in foxes (Vulpes vulpes).

This research article discusses the detection of Borna disease virus (BDV), a cause of encephalitis in horses and several other species, in various domestic animals and foxes in France. The study uses a method called RT-nested-PCR on 196 animal tissues to detect BDV RNA, identifying the virus in the brain samples of horses, foxes, and cattle, and in the blood samples of horses.

Overview of Borna Disease Virus (BDV)

BDV is an envelope-wrapped, non-sectioned negative-strand RNA virus from the Bornaviridae family. It is known to cause encephalitis, a brain condition that results in inflammation. The virus affects several vertebrates, including horses, sheep, and now, as the study shows, foxes.

Research Methodology

• The scientists conducted the study on 196 animal tissues. This included 171 brain samples from different animals (75 horses, 59 foxes, 31 cattle, 4 dogs, 1 sheep, 1 roe deer) and 25 blood samples from horses.
• The researchers used a technique called RT-nested-PCR. This is a method used in molecular biology to detect feeble signals of RNA sequences. It serves to extend the detection of RNA coming from the virus and increase the detection sensitivity.
• An RNA internal standard molecule was built and amplified along with the test template. This helps in providing a control for variations in the amount of RNA and the efficiency of reverse transcription, essential for the accurate quantitation of gene expression.

Findings of the Study

• The study found the presence of BDV RNA in 10 brain samples collected from horses, foxes, and cattle, and in 14 horse blood samples.
• This marks the first detection of BDV RNA in France – a significant finding considering the infectious and grave nature of the virus.
• An essential observation was the presence of the BDV genome in the brains of six red foxes. This marks the first recorded evidence of BDV infection in foxes, broadening the known range of animals that can be affected by the virus.