SUMMARY
Congenital cytomegalovirus (CMV) infections are a leading cause of sensorineural hearing loss (SNHL) and neurological impairment. Congenital transmission of CMV can occur with maternal primary infection, reactivation, or reinfection during pregnancy. We reviewed studies of CMV shedding in bodily fluids (defined as CMV detected by culture or CMV DNA detected by polymerase chain reaction). Following diagnosis at birth, children with congenital CMV infection exhibited the highest prevalences of CMV shedding (medianโ=โ80%, number of sample population prevalences [N]โ=โ6) and duration of shedding, with a steep decline by age five. Healthy children attending day care shed more frequently (medianโ=โ23%, Nโ=โ24) than healthy children not attending day care (medianโ=โ12%, Nโ=โ11). Peak shedding prevalences in children occurred at 1โ2โyears of age, confirming that young children are the key transmission risk for pregnant women. CMV shedding among children was more prevalent in urine specimens than in oral secretions (median prevalence differenceโ=โ11.5%, Nโ=โ12). Adults with risk factors such as STD clinic attendance had higher shedding prevalences (medianโ=โ22%, Nโ=โ20) than adults without risk factors (medianโ=โ7%, Nโ=โ44). In adults with risk factors, CMV was shed more frequently in urine; in adults without risk factors genital shedding was most common. The prevalence of CMV shedding in nine sample populations of pregnant women increased with advancing gestation. In seven sample populations of children with congenital CMV infection, higher viral load at birth was consistently associated with an elevated risk of SNHL. Higher CMV viral load at birth also consistently correlated with the presence of symptoms of congenital CMV at birth. Published 2011. This article is a US Government work and is in the public domain in the USA.