Experimental placental transfer of Akabane virus in the hamster

Transplacental infection of hamster fetuses was produced by inoculation of pregnant hamsters with 10(6.3) plaque-forming units (PFU) of Akabane virus by either the intraperitoneal or the subcutaneous route. Virus with titers as high as 10(7.5) PFU/g of tissue was detected first in the placenta and later in the fetus. Virus could also be readily isolated from blood, lung, spleen, and liver of both pregnant and nonpregnant hamsters, but it reached higher titers and persisted longer in the placenta and fetus. Young dying at birth had Akabane virus titers as high as 10(7.3) PFU/g of brain tissue. Litter size was reduced by inoculation of the pregnant hamster at gestational day 11 or earlier, and survival of the newborn to 1 week of age was decreased by inoculation at gestational day 9 or later.