Long-term Outcomes of Congenital Cytomegalovirus Infection in Sweden and the United Kingdom

Background. Congenital cytomegalovirus (CMV) is an important cause of neurological problems, particularly sensorineural hearing loss, but data on long-term sequelae and the impact of nonprimary maternal infection are limited. We report updated findings on childhood outcomes from 2 large prospective studies. Methods. Pregnant women in Malmö, Sweden, and London, United Kingdom, were included between 1977 and 1986, and newborns were screened for CMV (virus culture of urine or saliva). Cases and matched controls underwent regular, detailed developmental assessments up to at least age 5 years. Results. One hundred seventy-six congenitally infected infants were identified among >50 000 screened (Malmö: 76 [4.6/1000 births]; London: 100 [3.2/1000 births]); 214 controls were selected. Symptoms were recorded in 11% of CMV-infected neonates (19/176) and were mostly mild; only 1 neonate had neurological symptoms. At follow-up, 7% of infants (11/154) were classified as having mild, 5% (7/154) moderate, and 6% (9/154) severe neurological sequelae. Four of 161 controls (2%) had mild impairment. Among children symptomatic at birth, 42% (8/19) had sequelae, versus 14% (19/135) of the asymptomatic infants (P=.006). All moderate/severe outcomes were identified by age 1; mild sequelae were first identified at age 2-5 years in 6 children, and age 6-7 years in 3. Among the 16 children with moderate/severe outcomes, 2 had mothers with confirmed and 7 with presumed nonprimary infection. Conclusions. Moderate or severe outcomes were reported in 11% of children with congenital CMV identified through population screening, all by 1 year; all impairment detected after this age was mild. Nonprimary infections contributed substantially to the burden of childhood congenital CMV disease.