Auditory and visual defects resulting from symptomatic and subclinical congenital cytomegaloviral and toxoplasma infections.

Sensorineural hearing loss was present in ten of 59 (17%) patients with congenital cytomegalovirus (CMV) infection (three of eight born with symptomatic and seven of 51 born with subclinical infection). The defect was bilateral in eight, moderate to profound in eight, and of progressive nature in two. Hearing loss did not occur in 21 patients with natal CMV infection nor in seven of 12 patients with congenital toxoplasmosis. Histopathologic and immunofluorescent studies of the inner ear in two of three neonates who died with severe infection revealed that viral antigens were widely distributed in cochlear structures. Eye pathology was associated only with congenital Toxoplasma (nine of 12) and CMV (seven of 43) infections. Visual impairments were more prominent and severe in those born with symptomatic infections, exclusively so with CMV. However, ocular defects, in particular chorioretinitis, developed after birth in five of eight patients born with asymptomatic congenital toxoplasmosis. These data firmly establish clinically inapparent congenital CMV infection as a major public health problem and confirm the fact that congenital toxoplasmosis may be associated with late-appearing, debilitating chorioretinitis.