Congenital cytomegalovirus labyrinthitis and sensorineural hearing loss in guinea pigs.

Cytomegalovirus (CMV) is the leading cause of human nonhereditary congenital deafness. The pathogenesis of congenital CMV infection in the auditory system is poorly understood and no suitable animal model is currently recognized. In this study primary maternal CMV infection in guinea pigs during the first or second trimester of pregnancy resulted in congenital infection in 64% of the offspring. Of the congenitally infected neonates, 28% had significant auditory deficits. Within the inner ear, CMV infection was localized in auditory nerve spiral ganglion cells. These findings indicate that congenital CMV infection of the guinea pig results in physiologic and anatomic neuropathology similar to that seen in human infection and provide the first experimental model for congenital CMV-induced sensorineural hearing loss.