Vertical transmission of West Nile virus in mammals and birds

Galkina A.Yu., Gerasimova A.D., Gusev E.A., Luchinin D.N., Molchanova E.V.

Volgograd Plague Control Research Institute of the Federal Service for Surveillance in the Sphere of Consumers Rights Protection and Human Welfare, Volgograd, Russia

The affinity of West Nile virus (WNV) to the tissues of the genitourinary system contributes to the possibility of pathogen transmission to offspring. In order to determine the potential for vertical transmission of WNV in birds and mammals, common quail and white mice were subcutaneously infected. The presence of the virus in the test material was determined by virological and molecular genetic methods.
Vertical transmission of WNV in common quail was carried out in 34.5% with an average virus titer of 104±0.4 PFU/ml, in white mice – in 60.9% in a titer of 104.2±1.1 PFU/ml. In avian eggs, the virus was present in the blastodisc, chorioallantoic membrane, and embryonic muscles. Part of the hatched chicks had congenital abnormalities. In mice, different susceptibility of embryos to the virus was established depending on the gestational age at which the infection was carried out. High titers of the virus were present in the placenta of experimental animals.
The data obtained indicate a high potential for vertical transmission of WNV in quail and white mice, which causes the risk of developing anomalies in the offspring and complications of pregnancy, up to death in mammals.