Transplacental and oral transmission of wild-type bluetongue virus serotype 8 in cattle after experimental infection.
Potential vertical transmission of wild-type bluetongue virus serotype 8 (BTV-8) in cattle was explored in this experiment. We demonstrated transplacental transmission of wild-type BTV-8 in one calf and oral infection with BTV-8 in another calf. Following the experimental BTV-8 infection of seven out of fifteen multi-parous cows eight months in gestation, each newborn calf was tested prior to colostrum intake for transplacental transmission of BTV by RRT-PCR. If transplacental transmission was not established the calves were fed colostrum from infected dams or colostrum from non-infected dams spiked with BTV-8 containing blood. One calf from an infected dam was born RRT-PCR positive and BTV-specific antibody (Abs) negative, BTV was isolated from its blood. It was born with clinical signs resembling bluetongue and lived for two days. Its post-mortem tissue suspensions were RRT-PCR positive. Of the seven calves fed colostrum from infected dams, none became infected. Of the six calves fed colostrum from non-infected dams spiked with infected blood, one calf became PCR-positive at day 8 post-partum (dpp), seroconverted 27 days later, and remained RRT-PCR and Abs positive for the duration of the experiment (i.e., 70dpp). This work demonstrates that transplacental transmission in late gestation and oral infection of the neonate with wild-type BTV-8 is possible in cattle under experimental conditions.
Department of Virology, Central Veterinary Institute of Wageningen University and Research, Lelystad, The Netherlands. anoek.backx@wur.nl
Anoek
A
Backx
René
R
Heutink
Eugene
E
van Rooij
Piet
P
van Rijn
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001819:Bluetongue / Q000097:blood / Q000635:transmission / Q000821:virology*; D001820:Bluetongue virus / Q000145:classification*; D002417:Cattle; D005260:Female; D018445:Infectious Disease Transmission, Vertical / Q000662:veterinary; D011247:Pregnancy
D000914:Antibodies, Viral