Congenital Cytomegalovirus and Hearing Loss: The State of the Art

Abstract

In developed countries, congenital cytomegalovirus (cCMV) infection is the most common congenital viral infection, representing the leading non-genetic cause of sensorineural hearing loss (HL). Diagnosis of cCMV infection can be performed by detection of CMV DNA in urine or saliva within 2–3 weeks after birth, or later in dried blood samples on the Guthrie card. Currently, there are many controversies regarding the preventive, diagnostic, and therapeutic approaches to cCMV infection. HL secondary to cCMV is highly variable in onset, side, degree, audiometric configuration, and threshold changes over time. Therefore, it is of paramount importance to perform a long and thorough audiological follow-up in children with cCMV infection to ensure early identification and prompt treatment of progressive and/or late-onset HL. Early cochlear implantation appears to be a valid solution not only for children with bilateral profound HL, but also for those with single-sided deafness, improving localization ability and understanding speech in noisy environments. Moreover, the decision to apply a unilateral cochlear implant in children with cCMV is strengthened by the non-negligible possibility of hearing deterioration of the contralateral ear over time.

Maternal serological screening for cytomegalovirus infection may play an important role nowadays

“…1 This strategy is often legitimized by valid and complex reasons, such as the inability of laboratory tests to predict which newborn will develop long-term hearing loss or other neurodevelopmental complications, and the potentially increased rate of unnecessary abortions. 2,3 However, we fully agree with the authors that the current recommendations are characterized by limited and low-level evidence, 1 and we would like to emphasize some important concepts.…”

“…In their comprehensive systematic review, the authors found that none of the clinical practice guidelines or consensus statements recommended universal serological screening for cytomegalovirus (CMV) in pregnant women 1 . This strategy is often legitimized by valid and complex reasons, such as the inability of laboratory tests to predict which newborn will develop long‐term hearing loss or other neurodevelopmental complications, and the potentially increased rate of unnecessary abortions 2,3 …”

“…In our opinion, it should be highlighted that maternal serological screening for CMV infection may promote (1) primary prevention (to reduce the risk of maternal primary infection and reinfection) by inducing greater adherence to hygienic‐behavioral rules in CMV‐seronegative pregnant women; (2) secondary prevention (to reduce the risk of maternal‐fetal transmission) by ensuring that valaciclovir treatment can be initiated as soon as possible after maternal CMV seroconversion; (3) tertiary prevention (to reduce the impact of congenital CMV infection on children's hearing and neurodevelopmental outcomes) by fostering targeted newborn CMV screening that can ensure proper follow‐up and possible timely use of valganciclovir in children diagnosed with congenital CMV infection 2,3 . Indeed, pregnant women who are aware that they are susceptible to primary CMV infection based on serology are more likely to practice proper hygiene measures, such as avoid changing diapers or practicing unsafe sex 2 . Moreover, early diagnosis of maternal primary infection may allow timely administration of oral valaciclovir, which could be effective in reducing the rate of fetal CMV infection 4 .…”

“…2,3 Indeed, pregnant women who are aware that they are susceptible to primary CMV infection based on serology are more likely to practice proper hygiene measures, such as avoid changing diapers or practicing unsafe sex. 2 Moreover, early diagnosis of maternal primary infection may allow timely administration of oral valaciclovir, which could be effective in reducing the rate of fetal CMV infection. 4 Finally, performing targeted neonatal CMV screening in newborns whose mothers become seropositive during pregnancy may help identify asymptomatic congenital CMV cases in an early stage, ensuring the most appropriate management.…”

Unilateral Sensorineural Hearing Loss in Children: Etiology, Audiological Characteristics, and Treatment

“…The prevalence of congenital UHL is about 0.3–1 per 1000 newborns, with a remarkable increase (1.2–4.6 per 100) in newborns admitted to the neonatal intensive care unit [ 4 ]. However, it is important to underline that most children with mild HL and those with late-onset or acquired HL are not identified by universal newborn hearing screening [ 1 , 5 ]. Moreover, a recent study by Fitzpatrick et al reported that nearly half of children with UHL are at risk of experiencing further hearing decline in the affected ear or developing bilateral HL [ 6 ].…”