Congenital cytomegalovirus (CMV) infection as a cause of permanent bilateral hearing loss: a quantitative assessment.

BACKGROUND Congenital cytomegalovirus (CMV) infection is a cause of sensorineural hearing loss (SNHL) in children, but the magnitude of its contribution is uncertain. Quantifying the impact of congenital CMV infection requires an evidence-based assessment using a standard case definition of hearing loss. OBJECTIVES To determine the frequency of bilateral moderate to profound SNHL in children with congenital CMV infection and to estimate the CMV-attributable fraction of bilateral moderate to profound SNHL. STUDY DESIGN A systematic review of studies of children with congenital CMV infection ascertained in an unbiased manner through universal newborn screening for CMV using viral culture in urine or saliva specimens in combination with a review of the literature on congenital CMV infection and hearing loss, including articles of all types. RESULTS Approximately, 14% of children with congenital CMV infection develop SNHL of some type, and 3-5% develop bilateral moderate to profound SNHL. Among all children with bilateral moderate to profound SNHL, we estimate that 15-20% of cases are attributable to congenital CMV infection. CONCLUSIONS Congenital CMV infection is one of the most important causes of hearing loss in young children, second only to genetic mutations, and is potentially preventable.