Clinical bottom line
Congenital cytomegalovirus (cCMV) infection is a leading non-genetic cause of pediatric sensorineural hearing loss (SNHL), often presenting with delayed onset or progressive hearing impairment. Early identification through targeted screening and timely antiviral therapy may improve auditory outcomes, but variability in clinical presentation and diagnostic challenges remain. Current evidence supports heightened clinical vigilance for cCMV in infants with SNHL and consideration of multidisciplinary management, although standardized protocols for screening and treatment are still evolving.
What the evidence shows
Congenital CMV infection affects approximately 0.5–1% of live births worldwide and is a significant contributor to pediatric SNHL (Singh et al., 2022). The hearing loss associated with cCMV can be present at birth or develop later in childhood, often progressing over time (Riga et al., 2018). This delayed or progressive nature complicates early diagnosis and intervention.
Several studies have highlighted the heterogeneity of SNHL in cCMV. Harris et al. (1984), one of the earliest landmark studies, demonstrated that SNHL in cCMV can be unilateral or bilateral and varies in severity. More recent systematic reviews confirm that SNHL may worsen during childhood, underscoring the need for ongoing audiological monitoring (Riga et al., 2018).
Neuroimaging abnormalities, such as intracranial calcifications and white matter changes, have been associated with cCMV-related SNHL, suggesting a broader neurological involvement (Shapiro et al., 2010). These findings may help stratify risk and guide prognosis but are not universally present.
Antiviral treatment with valganciclovir in symptomatic infants, particularly those with central nervous system involvement, has shown some benefit in stabilizing or improving hearing outcomes (Singh et al., 2022). However, the optimal timing, duration, and patient selection criteria for antiviral therapy remain under investigation.
Screening strategies vary globally. Universal newborn CMV screening is not yet standard practice in many regions, but targeted screening of infants who fail newborn hearing screening is increasingly advocated to facilitate early diagnosis (BARBI et al., 2003). Early identification allows for timely audiological intervention, including hearing amplification or cochlear implantation when indicated.
Caveats and uncertainty
The natural history of cCMV-related SNHL is variable and incompletely understood. Some children with cCMV may never develop hearing loss, while others experience rapid progression, complicating prognostication (Wiwanitkit et al., 2017). The sensitivity and specificity of current diagnostic tests, including PCR from saliva or urine, depend on timing and specimen quality, which can lead to missed diagnoses if testing is delayed beyond the neonatal period.
Antiviral therapy carries risks, including neutropenia and other adverse effects, and its long-term benefits for hearing preservation require further validation in randomized controlled trials (Singh et al., 2022). Moreover, the impact of antiviral treatment on late-onset or progressive hearing loss remains unclear.
There is no consensus on universal versus targeted CMV screening in newborns, and cost-effectiveness analyses vary by healthcare setting. Additionally, the role of adjunctive therapies, such as corticosteroids or novel antivirals, has not been established.
How this may change practice
Otolaryngologists and pediatricians should maintain a high index of suspicion for cCMV in infants and children presenting with SNHL, especially when onset is delayed or progressive. Incorporating targeted CMV testing for infants who fail newborn hearing screening may facilitate earlier diagnosis.
Multidisciplinary management involving infectious disease specialists, audiologists, and neurologists is advisable for comprehensive care. Early antiviral therapy should be considered in symptomatic infants with confirmed cCMV, balancing potential benefits against risks.
Regular audiological surveillance is critical given the risk of progressive hearing loss. Clinicians should counsel families about the variable prognosis and the importance of follow-up.
Future practice may be shaped by emerging evidence supporting expanded newborn CMV screening programs and refined antiviral treatment protocols, but current approaches should be individualized based on clinical presentation and resource availability.