Postnatal CMV: An Underestimated Risk for Infant Hearing!

#Cytomegalovirus  #CMV  #Hearing  #Neurodevelopment  #Prevention  #Pediatrics


Postnatal infection with cytomegalovirus (CMV) is a common viral disease that primarily affects infants, particularly in regions with a high prevalence of the virus. Generally considered benign in full-term, healthy newborns, the impact of postnatal CMV on auditory and neurological development remains uncertain.

The main challenge associated with this infection lies in its insufficient diagnosis and follow-up. Current neonatal screening programs focus on the congenital form of the infection, neglecting infants infected after birth. This lack of follow-up limits the understanding of long-term consequences and complicates the identification of children at risk for sensory or cognitive disorders. Recent advances in molecular screening techniques allow easier identification of postnatal infection. When combined with early hearing screening programs, they open new perspectives for managing CMV-exposed infants. However, the link between postnatal infection and potential alterations in brain or auditory development remains controversial.

This study explores the impact of postnatal CMV on hearing and neurological development in infants aged 3 to 10 months. By comparing children infected after birth with non-infected infants, it aims to determine whether early screening and management of this infection could improve care and follow-up for at-risk populations.

Postnatal CMV: A Silent Threat to Infant Hearing?

A subgroup of 438 full-term infants was selected:

• 219 tested negative for CMV at birth but had a confirmed postnatal infection at 3 months of age,
• 219 remained negative and served as the control group.

CMV diagnosis was established by PCR amplification on saliva samples, confirmed by urine analysis. Infants were followed until 10 months of age to assess the effects of infection on hearing and neurodevelopment. Neurological development was analyzed using the Malawi Developmental Assessment Tool (MDAT) and the Hammersmith Infant Neurological Examination (HINE). Auditory assessment relied on otoacoustic emissions (OAE) tests.

Among the 424 infants followed until 10 months, no significant impact of postnatal infection on neurodevelopmental outcomes was identified. However, infected infants showed an increased risk of abnormal hearing test results (32.5% vs. 17.9% in the control group), with a relative risk of 1.99. These results suggest an association between postnatal CMV infection and a higher risk of hearing impairment, although the early-life neurological impact appears limited.

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Postnatal CMV: Should We Rethink Our Approach?

Postnatal cytomegalovirus is a common infection among infants, especially in regions where the virus is highly prevalent. Often asymptomatic, it remains poorly studied, particularly regarding its potential effects on hearing. Unlike congenital CMV, it is not included in neonatal screening programs, making it difficult to identify at-risk children. The lack of early monitoring limits prevention and management of auditory or neurodevelopmental disorders that may arise.

This study investigates the impact of postnatal CMV on hearing and neurological development in infants aged 3 to 10 months. The results indicate that while this infection has no significant effect on child development, it is associated with an increased risk of hearing impairment, emphasizing the need for appropriate care.

However, the study has some limitations, including a follow-up period that is too short to assess long-term effects on hearing and neurological development. Additionally, the auditory assessment was limited to otoacoustic emissions, without more precise tests such as auditory evoked potentials, making the evaluation incomplete. These findings highlight the importance of integrating CMV screening and hearing tests into pediatric care, particularly in high-prevalence areas. Prolonged follow-up of infected children would allow for a more precise identification of risks and the adaptation of management strategies to reduce associated complications.