Experimental and natural borna disease virus infections: presence of viral RNA in cells of the peripheral blood.

The research article examined the presence of Borna disease virus (BDV) RNA in peripheral blood cells of both experimentally and naturally infected animals as well as humans. The study used a highly sensitive reverse transcription-polymerase chain reaction (RT-PCR) method which yielded promising results, even suggesting an unexpected role of blood in the transmission of BDV.

Methodology

• The researchers analyzed peripheral blood cells from BDV-infected animals and humans (including healthy individuals and those with psychiatric disorders) for the presence of viral RNA. This was done using a BDV-p40-specific nested reverse transcription-polymerase chain reaction (RT-PCR).
• The RT-PCR assay used in the study demonstrated high sensitivity, with the ability to amplify as few as 10 RNA molecules reliably.

Results

• In the case of experimentally infected mice and rats, BDV RNA was found in the blood cells. Mice showed persistent infection without clinical signs of Borna disease (BD), whereas rats experienced the acute manifestation of BD.
• Out of 19 tested horses, five were found to have viral RNA in their blood. Among 25 sheep from a flock with a history of BD, one clinically healthy individual tested positive for BDV RNA.
• The study also tested humans and found BDV RNA in peripheral blood cells in 10 out of 27 individuals with psychiatric disorders and in 2 out of 13 healthy individuals. Notably, in some cases, BDV-specific RNA was present even when there were no BDV-specific antibodies.
• The researchers confirmed the specificity of their amplification system through sequence analysis of PCR products.

Implications

• The findings of the research suggest the possible role of blood in the transmission or spread of BDV within an infected organism, and also in the transmission of BDV to other individuals.
• Moreover, the presence of BDV RNA in humans, including healthy individuals, implicates a potential association with psychiatric disorders, warranting further investigation.
• The high sensitivity of the RT-PCR assay used in the study could potentially be employed in future diagnostics and research for BDV and other viral infections.