Cytomegalovirus and the Brain

To the Editor.— Conboy et al1 report a study on the intellectual development of 6- to 12-year-old children with congenital cytomegalovirus infection. We are in complete agreement with the authors' emphasis on looking for impairment in asymptomatic children with cytomegalovirus, who make up about 90% of all children with congenital cytomegalovirus. However, we believe that their study is less than definitive in ruling out the possibility that congenital cytomegalovirus infection, even when asymptomatic, can lead to intellectual impairment: Size of Study.