Hearing loss in children with congenital cytomegalovirus infection: an 11-year retrospective study based on laboratory database of a tertiary paediatric hospital

Congenital Cytomegalovirus-Related Hearing Loss

Congenital hearing loss is a significant global health concern that affects millions of newborns and infants worldwide, posing substantial challenges for affected individuals, their families, and healthcare systems. This condition, present at birth, can stem from genetic factors, in utero exposures, infections, or complications during pregnancy or childbirth. The spectrum of congenital hearing loss ranges from mild to profound, impacting the development of speech, language, and cognitive skills, thereby influencing educational achievements, social integration, and future employment opportunities. Early detection and intervention strategies, such as newborn hearing screenings, genetic counseling, and the use of hearing aids or cochlear implants, are crucial for mitigating these impacts. This review article aims to explore the diagnostic approaches and management strategies for congenital cytomegalovirus-related hearing loss, emphasizing the importance of interdisciplinary care and the potential for technological advances to improve outcomes for affected individuals.

The Audiological Follow-Up of Children with Symptomatic Congenital Cytomegalovirus Infection: An Experience in Two Italian Centers

BACKGROUND

Congenital cytomegalovirus (cCMV) infection is the leading cause of non-hereditary sensorineural hearing loss in children. While about 10% of children reportedly display symptoms at birth, 85-90% of cCMV infection cases are asymptomatic. However, 10-15% of these asymptomatic infants may later develop hearing, visual, or neurodevelopmental impairments. This study aimed to evaluate the impact of cCMV infection on newborns' hearing function with a particular emphasis on progressive and late-onset cases.

METHODS

This study is a retrospective chart analysis with longitudinal character and was conducted in two Italian centers: Center 1 (from 1 November 2007 to 31 December 2021) and Center 2 (from 1 January 2012 to 31 December 2021). Data collected included newborn hearing screening results, characterization of hearing loss (unilateral/bilateral, degree of impairment), and audiological follow-up.

RESULTS

The cohort consisted of 103 children (42% males, 58% females). In total, 28 children presented with hearing impairment; 71.4% (20 out of 28) of the cases of hearing loss were severe/profound, with 35.7% of the cases due to unilateral hearing loss. Out of twenty-eight, six experienced progression of hearing loss and four had late-onset hearing loss.

CONCLUSIONS

In the absence of universal cCMV screening, hearing screening at birth for cCMV remains a critical factor for early diagnosis. A significant percentage of children affected by cCMV with normal audiological evaluations at birth is easily lost to follow-up. Close collaboration between neonatologists, pediatricians, and audiological services is fundamental to ensure timely diagnosis and treatment of cCMV-related hearing loss.

Hearing Outcome and Virologic Characteristics of Children With Congenital Cytomegalovirus Infection in Relation to Antiviral Therapy: A Retrospective Cohort Study

BACKGROUND

Congenital cytomegalovirus infection is one of the leading causes of nongenetic sensorineural hearing loss. The aim of our retrospective cohort study was to describe the changes in hearing in relation to antiviral therapy and the trend in viremia and viruria in children with congenital cytomegalovirus infection.

METHODS

In the present study, data were collected from infants treated with valganciclovir for 6 weeks or 6 months or untreated, seen between 2000 and 2021 at the Infectious Diseases Unit, Meyer Children's University Hospital, Florence, Italy. Hearing deterioration was studied using Kaplan-Meier survival curves and risk factors for the outcome "deterioration" with Cox analysis.

RESULTS

Ninety-eight children were enrolled. Three children developed late hearing loss (2 children treated with valganciclovir for 6 weeks and 1 untreated). Kaplan-Meier survival curves of children treated for 6 weeks and 6 months overlapped until 36 months of life, after then 2 children of the 6-week group showed a worsening of hearing function (P = 0.609). Cox analysis did not show a significant impact of analyzed variables (group of therapy, viruria and viremia) on the outcome. The resolution of detectable viruria and viremia was significantly faster in the 6-month group (P = 0.011, <0.001, respectively).

CONCLUSIONS

Our study is the first that reports audiological characteristics at follow-up after 24 months of life in treated and untreated children with congenital cytomegalovirus infection. In our population, 6 months therapy may prevent the development of late hearing loss, although the different regimens did not differ in influencing the progression of congenital deafness.

Hearing outcomes in children with congenital cytomegalovirus infection: From management controversies to lack of parents' knowledge

OBJECTIVES

Congenital cytomegalovirus (cCMV) is the leading nongenetic cause of sensorineural hearing loss (HL). However, there are no universally accepted approaches to diagnosis, follow-up and treatment. The aim of this study was to evaluate the main characteristics of cCMV-infected children, focusing on their management and long-term hearing outcomes.

METHODS

This retrospective study included all children with cCMV infection who were referred to a third-level referral audiologic center for a 6-year hearing follow-up. The main information collected from the medical records included gestational age, birth weight, trimester of maternal seroconversion, hearing status at birth and after 6 years, hearing fluctuations, treatment with oral valganciclovir (within the first month of life and for 6 months), use of hearing devices, presence of speech-language delay, motor delay, cognitive delay and balance disorders, awareness of cCMV among parents, and parents' engagement in behaviors that could increase the risk of CMV infection during pregnancy.

RESULTS

A total of 141 children with cCMV infection (72 males and 69 females; mean gestational age: 37⁺³ weeks; mean birth weight: 2893 g) were assessed. Overall, 48 children (34.0%) had a diagnosis of speech-language delay, 32 (22.7%) of sensorineural HL (59.4% bilaterally; 50% of profound degree), 18 (12.8%) of motor delay, 16 (11.3%) of balance disorders, and 6 (4.3%) of cognitive delay. Among children with HL, 8 (25.0%) were fitted with hearing aids (5 unilaterally and 3 bilaterally), and 5 (15.6%) had undergone cochlear implantation (1 unilaterally and 4 bilaterally), while a bimodal hearing solution was adopted for 2 (6.3%) patients. Compared to children with asymptomatic cCMV infection, symptomatic children had a higher prevalence of neurological and auditory sequelae (P < 0.01) and bilateral (P = 0.003) and severe-to-profound HL (P = 0.004). 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 were aware that cCMV could cause progressive or late-onset HL, and 87.9% of parents (248/282) had engaged in behaviors that increased the risk of CMV infection during pregnancy.

CONCLUSION

This study confirmed the importance of performing a long audiological follow-up in children diagnosed with cCMV infection due to the possible late-onset, progressive and fluctuating nature of HL. Moreover, the study highlighted many current controversies in preventive (poor prenatal education), diagnostic (routine maternal serological screening) and therapeutic (valganciclovir administered to asymptomatic children) approaches to cCMV infection. More efforts should be made to improve prevention strategies and raise awareness of cCMV infection risks among the population.

Risk Factors for Sensorineural Hearing Loss and Auditory Maturation in Children Admitted to Neonatal Intensive Care Units: Who Recovered?

Background: Newborns admitted to neonatal intensive care units (NICUs) are at higher risk of developing sensorineural hearing loss (SNHL), which may improve over time. The aim of this study was to describe the prevalence of the main risk factors for SNHL in a NICU cohort, focusing on children who underwent auditory maturation. Methods: An observational study of 378 children admitted to NICUs, who were followed for at least 18 months, with periodic audiologic assessments. Results: Out of 378 patients, 338 had normal hearing and 40 were hearing-impaired; we found a higher percentage of extremely preterm (EPT) and extremely low-birthweight (ELBW) infants in SNHL children (p < 0.05). Seventeen infants presented auditory improvement, with a mean maturation time of 6.17 months. A significant difference emerged between patients with stable SNHL and those who improved only in the case of hyperbilirubinemia (p = 0.005). The initial hearing threshold was a predictor of auditory improvement and moderately correlated to the time of auditory maturation (p = 0.02). Conclusions: Our study supports the trend toward recognizing worse prognoses and slower maturation processes among NICU children who suffer from severe to profound SNHL. Caution must be taken when deciding on earlier cochlear implantation.

Hearing test results of newborns born from the coronavirus disease 2019 (COVID-19) infected mothers: A tertiary center experience in Turkey

Objective

Congenital infections can cause newborn hearing loss. Although vertical transmission of coronavirus disease 2019 (COVID‐19) infection is theoretically possible, this has not been proven yet. To our knowledge, there is no previous report on whether COVID‐19 infection during pregnancy can cause congenital hearing loss. This paper aimed to find an answer to this question.

Method

This retrospective, single‐center study was performed between April 2020 and May 2021 at a tertiary care referral center in Turkey. A total of 422 pregnant women who had coronavirus infection during pregnancy were followed and 203 of them gave birth in our institution. Results of hearing screening tests of 199 newborns were assessed retrospectively.

Results

Of patients included in the study, 23 (11.6%) had the disease in the first trimester, 62 (31.2%) in the second trimester, and 114 (57.3%) in the third trimester. In the first hearing test performed on newborns, unilateral hearing loss was observed in 21 babies (10.5%). Hearing tests of these newborns were found to be normal in the second test performed 15 days later.

Conclusion

Considering the incidence of congenital hearing loss, the absence of hearing loss in our newborn population does not confirm the argument that coronavirus infection does not cause congenital hearing loss. This issue should be evaluated with larger patient series. In addition, it should be kept in mind that hearing loss can occur at later ages as well.

Universal newborn hearing screening in the Italian Region of Sicily in 2018

OBJECTIVES

We have clarified the role of Universal Neonatal Hearing Screening (UNHS) for both early diagnosis and rapid treatment in order to improve the prognosis of the deaf child and reduce patient management costs. Although in Sicily UNHS has been progressively implemented, there is scarce data in the literature on this matter. Therefore, the main objective was to collect in the year 2018 the following data: number of newborns screened for hearing loss, number of infants "referred" to transiently evoked otoacoustic emissions (TEOAE), number of infants with pathologic auditory brainstem response (ABR) and number of infants affected by permanent hearing loss.

METHODS

UNHS monitoring was conducted through the collection of data through a questionnaire, which was analysed evaluating the effectiveness and adherence to the screening program prepared by the Department for Health Activities and the Epidemiological Observatory (DASOE).

RESULTS

In 2018, there were 40,243 newborns in Sicily. A total of 37,562 newborns were screened (93.3%). There were 1,328 "referred" infants with TEOAE (3.5%). On the 2nd level, "referred" newborns examined were 1,080 of 1,328 expected (missing 248 "refer" newborns, equal to 18.6%). The number of "referred" infants confirmed with TEOAE was 113 of 1,080, while "referred" infants confirmed with ABR were 71. On the 3rd level, 67 of 71 were infants examined: 28 infants were suffering from monolateral hearing loss (13 slight/mild, 13 moderate, 1 severe and 1 profound) and 39 from bilateral hearing loss (1slight/mild, 19 moderate, 13 severe and 7 profound). Excluding 7 infants from the NICU, 60 of 37,562 infants had hearing loss (1.5%).

CONCLUSIONS

The monitoring of the UNHS in Sicily has allowed obtaining the data of individual centres, absent in the literature to date, to verify the effectiveness of the screening, according to JCIH criteria, to highlight some criticalities and, finally, to propose possible solutions.

Efficacy of small-dose ganciclovir on cytomegalovirus infections in children and its effects on liver function and miR-UL112-3p expression

The aim of the study was to explore the efficacy of small-dose ganciclovir on cytomegalovirus infections as well as its effects on the liver function and miR-UL112-3p of children. A total of 141 children infected with cytomegalovirus admitted to the Affiliated Hospital of Weifang Medical University from May 2015 to August 2017 were enrolled, of which 74 children were treated with small-dose ganciclovir as an observation group (Obs group), and the rest were treated with conventional-dose ganciclovir as a control group (Con group). The two groups were compared in efficacy after treatment, changes of liver function indexes [total bilirubin (TB), alanine aminotransferase (ALT), and aspartate aminotransferase (AST)] and miR-UL112-3p before and after treatment, and adverse reactions after treatment. A receiver operating characteristic (ROC) curve was drawn to analyze the value of miR-UL112-3p in predicating efficacy on cytomegalovirus infections in children, and Pearson's correlation analysis was carried out to analyze the correlation between miR-UL112-3p expression and TB, ALT and AST. The MV-DNA level between the two groups after treatment was compared. The two groups showed no significant difference in efficacy and adverse reactions (both P>0.05), and before treatment, there was also no significant difference between the two groups in miR-UL112-3p, TB, ALT, and AST, while after treatment, both groups showed lower levels of miR-UL112-3p, TB, ALT, and AST, and the Obs group showed significantly lower levels thereof than the Con group (all P<0.05). In addition, the area under the curve (AUC), specificity, and sensitivity of miR-UL112-3p in the ROC curve of the Obs group were 0.866, 73.77 and 84.62%, respectively, while the AUC, specificity, and sensitivity of the ROC of the Con group were 0.837, 75.44, and 90.00%, respectively. Furthermore, miR-UL112-3p was positively correlated with TB, ALT, and AST, respectively. The CMV-DNA level in the Obs group was lower than that in the Con group, but the difference was not significant, and the level of CMV-DNA was positively correlated with that of miR-UL112-3p. In conclusion, small-dose ganciclovir can better improve the liver function of the children, and downregulate miR-UL112-3p in them. The AUC, specificity, and sensitivity of miR-UL112-3p for predicting the efficacy of small-dose ganciclovir were 0.866, 73.77 and 84.62%, respectively, and the AUC, specificity, and sensitivityfor predicting the efficacy of conventional-dose ganciclovir were 0.837, 75.44 and 90.00%, respectively.

Nanoparticles for the Treatment of Inner Ear Infections

The inner ear is sensitive to various infections of viral, bacterial, or fungal origin, which, if left untreated, may lead to hearing loss or progress through the temporal bone and cause intracranial infectious complications. Due to its isolated location, the inner ear is difficult to treat, imposing an acute need for improving current therapeutic approaches. A solution for enhancing antimicrobial treatment performance is the use of nanoparticles. Different inorganic, lipidic, and polymeric-based such particles have been designed, tested, and proven successful in the controlled delivery of medication, improving drug internalization by the targeted cells while reducing the systemic side effects. This paper makes a general presentation of common inner ear infections and therapeutics administration routes, further focusing on newly developed nanoparticle-mediated treatments.

Congenital Cytomegalovirus and Zika Infections

Congenital infections affecting newborn infants can have potentially devastating clinical outcomes. They are usually caused by viruses that infect mothers during pregnancy and are transmitted to the fetus or newborn during the prenatal, perinatal or postnatal periods. Congenital cytomegalovirus (cCMV) is the most common congenital infection affecting up to 2.5% of all live births. Even though most infected infants are asymptomatic at birth, cCMV is an important cause of neurodevelopmental impairment and represents the main cause of non-hereditary sensorineural hearing loss. Also, congenital Zika infection has emerged in recent years as a cause of microcephaly and neurodevelopmental delays. Currently, universal screening is not recommended for either infection in pregnant women or newborn infants. Therefore, screening for both conditions is based on multiple factors such as maternal immune status, exposure, and clinical manifestations of the infant. Use of antiviral medications on symptomatic cCMV has shown improvement in outcomes, in contrast with congenital Zika for which there are no therapeutic options available. Even though both viruses can be present in breast milk, there are no recommendations against breastfeeding in full-term infants. Close follow-up for affected infants is necessary to monitor for developmental delays and sensory impairments to implement interventional therapies at the earliest time possible.

Hearing loss in very preterm infants: should we wait or treat?

This study investigated hearing threshold changes during the first year of corrected age (CA) in infants admitted in a neonatal intensive care unit (NICU). In 5 years, 239 infants with birth weight (BW) ≤ 1,000 gm and/or gestational age (GA) ≤ 30 weeks were enrolled. Hearing was evaluated by oto-acoustic emission (OAEs) before discharge and auditory brainstem response (ABR) within 3 months of CA. Infants affected by unilateral or bilateral hearing loss were addressed to audiological follow-up until definitive diagnosis (within 6 months of CA). Changes in hearing threshold were also carefully analysed. 207 (86.6%) infants had normal hearing while 32 infants (13.4%) showed hearing loss (HL) at the confirmative ABR evaluation (9 mild, 16 moderate, 4 severe, 3 profound). The latter showed lower GA (27.7 ± 2 vs 28.4 ± 1.2; p = 0.0061) and BW (950 ± 390 vs 1,119 ± 326 gm; p = 0.0085). At final evaluation, 15 infants (47%) recovered a normal hearing. HL was confirmed in 17 patients. Among these, 3 infants were addressed to audiological follow-up (one case of mild unilateral hearing loss (UHL) and two with moderate UHL), while in 14 cases (44%) with bilateral sensory neural hearing loss (SNHL) (7 moderate, 4 severe, 3 profound) hearing aids were prescribed. They showed significantly lower GA and longer hospital stay in the NICU in comparison with infants without indication for audiological habilitation (18 infants) (GA 26.2 ± 2.2 weeks vs 28.4 ± 2.4; p = 0.01; NICU stay 132 ± 67 vs 59 ± 7; p = 0.0002). Definitive diagnosis was obtained at 5.9 ± 1.3 months of CA. Our study confirms the importance of audiological surveillance in preterm newborns. Hearing thresholds of preterm infants with hearing loss can change during the first year of CA and we observed normalisation in 47% of our patients. Most vulnerable to permanent SNHL were very preterm infants with a longer NICU stay, while a shorter stay represents a favourable prognostic factor for hearing improvement.