Congenital cytomegalovirus is the second most frequent cause of bilateral hearing loss in young French children.

Objective To estimate the prevalence of congenital cytomegalovirus (cCMV) among causes of bilateral hearing lossin young French children. Study design Children Results One hundred children with bilateral hearing losswere included at a median age of 15 months; the prevalence of cCMV was 8% (8/100) (95% CI, 2.7%-13.3%) in this population and 15.4% (8/52) in the subpopulation of children with profound bilateral hearing loss. Delayed neurodevelopment and brain abnormalities on computed tomography scan were found more often in children with cCMV than in children with hearing losswithout cCMV ( P = .027, P = .005). In 6 of 8 cCMV cases, cCMV infection had not been diagnosed before the study. Conclusions In a comprehensive study of the causes of bilateral hearing lossin young French children, cCMV is the second most frequent cause of hearing lossafter connexinmutations. It underlines that a majority of French children with hearing lossand cCMV are not diagnosed early and therefore may not benefit from early intervention including the possibility of neonatal antiviral treatment. These results make the case for promoting systematic cytomegalovirus screening in neonates with confirmed hearing lossidentified through neonatal hearing screening.