Transplacental transmission of Venezuelan equine encephalitis virus in horses.

This study explores the transmission of Venezuelan equine encephalitis virus from pregnant mares to their fetuses, finding evidence of transplacental transmission in four out of nine studied cases.

Objective and Methodology of the Study

• The research was specifically targeted at understanding the transplacental transfer of Venezuelan equine encephalitis virus in horses.
• The study examined nine pregnant mares infected with viral strain P-676, near their term, monitoring any infection in the fetuses.
• In addition, researchers conducted comparative analysis with two fetuses from mares infected with a different viral strain, MF-8.

Findings of the Research

• Results indicated transplacental transmission of the Venezuelan equine encephalitis virus, strain P-676, in four out of the nine fetuses studied.
• This transmission was confirmed through the recovery of the virus in high concentrations from the blood and organs of the affected fetuses.
• At the same time, the virus was not detected in the maternal blood of these pregnant horses, although neutralizing antibodies were present, which indicates that the mothers had an immune response to the virus.
• In contrast, the fetuses from mares infected with the MF-8 strain did not show evidence of in utero infection. This implies that not all strains of the Venezuelan equine encephalitis virus may be capable of transplacental transmission.

Implication of the Research

• The findings suggest a potential risk of vertical transmission of certain strains of Venezuelan equine encephalitis virus, specifically P-676 strain, within the equine population.
• This indicates a need for further research to understand the factors driving this differential transmission among different viral strains and potential prevention mechanisms or treatments could be instituted.