Long-term hearing outcomes in children with congenital cytomegalovirus infection

Aims The aim of the present study was to evaluate the main characteristics of children with congenital cytomegalovirus (cCMV), focusing on long-term hearing outcomes and management controversies. Population The study included all children who received a diagnosis of cCMV infection (performed by detection of CMV DNA in the urine or saliva within three weeks after birth) and underwent a comprehensive 6-year audiological follow-up, including otomicroscopy, tympanometry, reflex threshold measurements, and click evoked auditory brainstem responses (ABRs). Methods We reviewed the medical reports and charts of cCMV-infected children who were referred to our tertiary-level hearing referral center (in Milan, Italy) for a 6-year audiological follow-up. At the first audiological assessment (T0), all parents were also asked to answer questions about awareness of cCMV. Results A total of 141 children (72 male and 69 female) were assessed. Overall, 48 children (34.0%) had a diagnosis of speech-language delay, 32 (22.7%) of sensorineural hearing loss, 18 (12.8%) of motor delay, 16 (11.3%) of balance disorders, and 6 (4.3%) of cognitive delay. Half of the patients with hearing loss (n=16) had profound hearing loss (10 unilaterally and 6 bilaterally). Compared to children with asymptomatic cCMV infection, symptomatic children had a significantly higher prevalence of hearing loss at birth (P=0.007), hearing loss at the 6-year evaluation (P<0.001), hearing deterioration (P=0.003), hearing fluctuations (P=0.04), motor delay (P<0.001), speech-language delay (P<0.001), cognitive delay (P=0.01), and balance disorders (P=0.003). In 15 out of 16 cases (93.8%), hearing deterioration occurred in the first 4 years of age. Among children with confirmed hearing loss, 8 were fitted with hearing aids (5 unilaterally and 3 bilaterally), and 5 underwent cochlear implantation (1 unilaterally and 4 bilaterally), while a bimodal hearing solution was adopted for 2 children. Overall, 23 children (16.3%) received oral valganciclovir, and only one of them experienced hearing deterioration. Only 14.9% of mothers and 5% of fathers had been aware that cCMV can cause progressive or late-onset hearing loss. More than 3 out 4 mothers believed that they could have avoided the behaviors responsible for CMV infection if they had received adequate information prior to pregnancy Interpretation This study highlighted the importance of performing a long audiological follow-up in children diagnosed with cCMV, and suggested that further efforts are needed to provide proper prenatal education, without neglecting the male population. The role of oral valganciclovir in preventing (or improving) hearing loss is controversial; nevertheless, our experience showed a very low rate of hearing deterioration in children who had received the treatment. Conclusion All children with cCMV infection, even if asymptomatic and with normal hearing at birth, should undergo a long and thorough audiological follow-up due to the risk of delayed-onset, progressive, and fluctuating hearing loss. Currently, there are many controversies regarding the preventive, diagnostic, and therapeutic approaches to cCMV infection.