[Experimental hydrocephalus induced by intraplacental mumps virus inoculation]

Experimental production of congenital hydrocephalus was undertaken by inoculating mumps virus into pregnant hamsters intravenously or intraplacentally. When the mumps virus was inoculated intravenously on the 8th, 10th, 12th, or 14th day of gestation, some fetuses were aborted and those which could come to term did not develop hydrocephalus after birth. Offsprings from the mothers, which had had intraplacental inoculation on the 14th day of gestation, showed ventricular dilatation in about 28%. Histological examination revealed inflammatory infiltration on the surface of ependymal layers, subependymal edema and microglial activation in the underlying ependyma of the aqueduct. These findings were thought to have resulted from ependymitis caused by mumps virus. The transplacental infection of mumps virus is considered to be extremely rare. However, in such conditions as the placental barrier is impaired, mumps virus will possibly pass through the placenta, and will cause hydrocephalus to the infant.