Arthur J. Dahle

This investigation consisted of a longitudinal study of the effects of congenital cytomegalovirus (CMV) infection on hearing sensitivity in 860 children with documented asymptomatic or symptomatic congenital CMV infection. Of the 651 children with asymptomatic CMV infection, 48 (7.4%) developed sensorineural hearing loss (SNHL), compared to 85 (40.7%) of the children with symptomatic CMV infection. Children in both groups experienced latent effects consisting of delayed onset of loss, threshold fluctuations, and/or progressive loss of hearing. It can be concluded that congenital CMV infection is a leading cause of SNHL in children. The late onset and progression of loss necessitates continued monitoring of hearing sensitivity in this population.

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.

A longitudinal clinical, virologic and immunologic study found 18 patients with inapparent congenital cytomegalovirus infection among 267 neonates with elevated umbilical-cord IgM levels. Virus excretion persisted in most patients through the third year of life, and the concomitant antigenic stimulation resulted in an accelerated development of immunoglobulins M and G and in continued complement-fixing antibody production in 14. Some degree of sensorineural hearing loss occurred in nine of 16 patients tested as compared with two of 12 controls, and, in four, an auditory handicap was either proved or considered likely. A trend toward subnormal intelligence was observed in the infected children, and two manifested definite mental and social disability. Cytomegalovirus infection probably has an important causal role in mild to moderate auditory and mental dysfunction in childhood. (N Engl J Med 290:291–296, 1974)