Congenital cytomegalovirus infection: association between virus burden in infancy and hearing

Objective To determine the relationship between the virus burden in infancy and hearing loss in congenital CMV infection. Study design A cohort of 76 infants with congenital cytomegalovirus (CMV) infection identified by means of newborn virologic screening was monitored for outcome. The amount of infectious CMVwas analyzed in urine specimens obtained during early infancy. Peripheral blood (PB) samples obtained during early infancy were available from 75 children and CMV DNA was quantitated with a real-time quantitative polymerase chain reaction. Results Infants with clinical abnormalities at birth (symptomatic congenital CMV infection) had higher amounts of CMV in urine (P =.005) and CMV DNA in PB (P =.001) than infants with no symptoms. Eight children with and 4 children without symptoms had hearing loss. Among children without symptoms, those with hearing loss had a significantly greater amount of CMV in urine (P =.03) and PB virus burden (P =.02) during infancy than those with normal hearing. Infants with <5 3 103 pfu/mL of urine CMV and infants with <1 3 104 copies/mL of viral DNA in PB were at a lower risk for hearing loss. Conclusion In children with asymptomatic congenital CMV infection, hearing loss was associated with increased amounts of urine CMV and PB CMV DNA during early infancy. (J Pediatr 2005;146:817-23) C ytomegalovirus (CMV) is a common cause of congenital infection and a leading cause of hearing loss in children in theUnited States.1-4 Most children (approximately 85%) with congenital CMV infection develop normally, without anypermanent perceptual, cognitive, or motor deficits.2,3,5,6 Sensorineural hearing loss (SNHL) is observed in approximately 10 % to 15 % of children with congenital CMV infection.4,7-10 The majority of children with CMV-related hearing loss experience delayed onset loss and continued deterioration of hearing function (progressive hearin