[A multicenter study on the effects of congenital cytomegalovirus infection on hearing loss]

Objective: To assess the clinical features and effectiveness of antiviral therapy in newborns with sensorineural hearing loss (SNHL) caused by congenital congenital cytomegalovirus (cCMV) infection, and to speculate the risk factors for poor hearing outcomes. Methods: A multicenter prospective cohort study wasconducted, enrolling 176 newborns diagnosed with cCMV at four research centers in Zhejiang Province from March 1, 2021, to April 30, 2024. Clinical characteristics at birth were recorded and hearing was followed up. The children were divided into groups based on their condition at birth, specifically into asymptomatic, mild symptom, and moderate to severe symptom groups. Additionally, they were divided into SNHL and normal hearing groups based on the results of air conduction brainstem audiometry at birth. And they were also divided into treatment and untreated groups according to antiviral treatment. Mann Whitney U test, and chi square test were used for inter group comparison to analyze the differences in clinical features between different disease groups, and to analyze the effects of clinical features, antiviral therapy, and other factors on hearing improvement. Logistic regression analysis was employed to identify the risk factors influencing hearing outcomes. Results: Among the cohort of 176 children diagnosed infection with cCMV, 90 cases were male and 86 cases were female. Of these, 79 cases were asymptomatic, 12 cases classified as mild cCMV and 85 cases as moderate to severe cCMV. Fifty cases belonged to SNHL group, with different degrees of severity, including 30 cases of mild, 9 cases of moderate, 5 cases of severe, and 6 cases of extremely severe SNHL. Among the 121 cases in the normal hearing group, 2 cases (1.7%) exhibited late-onset hearing loss despite having normal hearing at birth. Among 81 cases (46.0%) who completed the hearing follow-up, 71 cases (87.7%) had good hearing outcomes and 10 cases (12.3%) had poor hearing outcomes. Among the 81 children, 29 cases (35.8%) had SNHL at birth. During follow-up, the hearing threshold improved in 19 cases (65.5%), remained stable in 7 cases (24.1%) and progressed in 3 cases (10.3%). A total of 26 cases in the treatment group and 55 cases in the untreated group completed the hearing follow-up assessment. The rate of hearing improvement in the treatment group was found to be higher compared to the untreated group (13 cases (50.0%) vs. 6 cases (10.9%), χ²=15.00, P<0.01), with individuals in the treatment group having a 4.58 times greater likelihood of experiencing hearing improvement (RR=4.58,95%CI 1.96-10.70, P<0.05). However, no statistically significant difference was observed in hearing outcomes between the antiviral treatment group and the untreated group (RR=0.90, 95%CI 0.57-1.41, P=0.517). Multivariate analysis further confirmed SNHL (OR=11.58, 95%CI 2.10-63.93, P=0.005) and preterm birth (OR=4.98, 95%CI 1.06-23.41, P=0.042) as independent risk factors for poor hearing outcomes. Conclusions: SNHL resulting from cCMV infection presents symptoms at birth and can be improved by antiviral therapy. Poor hearing outcomes are associated with SNHL and prematurity.