Embryonic Origins of Virus-Induced Hearing Loss: Overview of Molecular Etiology

Impact on the first year of life of newborns with gestational infection by SARS-COV-2. Analysis of auditory effects

Introduction

One of the causes of congenital hearing loss are infections suffered by the mother during pregnancy. The objective of this study was to investigate the effects on hearing in newborns to SARS-CoV-2 seropositive mothers during pregnancy. We also studied the hearing impact in the first year of life of the newborns to investigate whether neonatal infection produced a risk of infantile sensorineural hearing loss.

Material and methods

All children born in our center whose mother had been infected with SARS-CoV-2 positive COVID were included and were audiologically studied at two and a half months and at one year of life. All infants were evaluated by brainstem evoked response audiometry (BERA) and auditory steady-state responses (ASSR).

Results

The range of the latencies for BERA founded were inside the desired ranges of normality both at two and a half months and at one year of life No significant differences by sex and ears were found in the BERA performed (p > 0,05). The mean ASSR values were found to be significantly below 30 dB in all frequencies studied both at two and a half months, and at one year of life (p < 0,05).

Conclusion

There is no association between COVID-19 infection during pregnancy and neonatal hearing loss. Further studies are needed to clarify this field since it is still unclear whether pregnant women infected with SARS-CoV-2 can produce hearing alterations in their newborns according to the current evidence in the literature.

Auditory Screening in Newborns after Maternal SARS-CoV-2 Infection: An Overview

BACKGROUND AND AIM

Several viruses have previously been reported to be responsible for congenital hearing loss; therefore, since the beginning of the SARS-CoV-2 infection pandemic, various reports have investigated a possible link. The aim of this review is to assess the possible link between maternal COVID-19 infection and congenital hearing loss.

METHODS

This systematic review was performed using PRISMA criteria, searching Medline and Embase databases from March 2020 to February 2023. A total of 924 candidate papers were identified; however, considering the specific selection criteria, only nine were selected for additional analysis.

RESULTS

The overall number of children born from mothers infected with COVID-19 during pregnancy identified through this review was 1687. The confirmed cases of hearing loss were 0.7% (12/1688); a description of its nature (sensorineural vs. conductive) is missing in the selected studies, and the follow-up period is variable across the analyzed papers. Surprisingly, a large proportion of false positives were recorded at the first stage of screening, which resulted normal at the re-test.

CONCLUSIONS

Currently, a correlation between congenital hearing loss and SARS-CoV-2 infection cannot be definitively established. Further studies are desirable to provide additional evidence on this topic.

Retinol and Pro-Vitamin A Carotenoid Nutritional Status during Pregnancy Is Associated with Newborn Hearing Screen Results

The prenatal period is critical for auditory development; thus, prenatal influences on auditory development may significantly impact long-term hearing ability. While previous studies identified a protective effect of carotenoids on adult hearing, the impact of these nutrients on hearing outcomes in neonates is not well understood. The purpose of this study is to investigate the relationship between maternal and umbilical cord plasma retinol and carotenoid concentrations and abnormal newborn hearing screen (NHS) results. Mother-infant dyads (n = 546) were enrolled at delivery. Plasma samples were analyzed using HPLC and LC-MS/MS. NHS results were obtained from medical records. Statistical analysis utilized Mann-Whitney U tests and logistic regression models, with p ≤ 0.05 considered statistically significant. Abnormal NHS results were observed in 8.5% of infants. Higher median cord retinol (187.4 vs. 162.2 μg/L, p = 0.01), maternal trans-β-carotene (206.1 vs. 149.4 μg/L, p = 0.02), maternal cis-β-carotene (15.9 vs. 11.2 μg/L, p = 0.02), and cord trans-β-carotene (15.5 vs. 8.0 μg/L, p = 0.04) were associated with abnormal NHS. Significant associations between natural log-transformed retinol and β-carotene concentrations and abnormal NHS results remained after adjustment for smoking status, maternal age, and corrected gestational age. Further studies should investigate if congenital metabolic deficiencies, pesticide contamination of carotenoid-rich foods, maternal hypothyroidism, or other variables mediate this relationship.

The role of Herpes Simplex Virus type 1 in oral diseases in children

Relevance. Herpes virus infections are the most common and poorly controllable viral infections. There are many difficulties in herpetic lesion verification and treatment in dental practice.

Purpose. The study aimed to present the results of a foreign publication investigation on the role of herpes simplex virus type 1 in the development of oral diseases in children.

Material and methods. Foreign scientific articles about the oral HSV-1 infections published from 2018 to 2022 formed the basis for the study. The study searched the publications on PubMed and Google Scholar bases.

Results. The article presents the newest data on the prevalence, clinical characteristics and diagnosis of oral HSV infection in children. Primary herpetic gingivostomatitis (PHGS), chronic recurrent herpetic gingivostomatitis, chronic recurrent herpes labialis are the main clinical presentations of herpes infection diagnosed in a dental practice. Primary herpetic gingivostomatitis is very common in children aged six months to fve years and occurs in newborns from 2 to 43 days of life. Modern virology success can improve diagnosis and treatment of oral herpetic lesions.

Conclusion. Primary herpetic gingivostomatitis is an acute infectious disease that requires the joint attention of a general practitioner and a dentist to ensure comprehensive treatment.

Can SARS-CoV-2 positive pregnant women affect the hearing of their newborns: A systematic review

The 2019 coronavirus disease (COVID-19) pandemic has caused over 500 million confirmed cases (including pregnant women) worldwide. Recently, hearing status in newborns born to mothers with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has received attention. This systematic review outlines the current knowledge regarding the effects of maternal SARS-CoV-2 infection during pregnancy on newborn hearing. Intrauterine SARS-CoV-2 infection has the potential to affect the auditory system of the newborn due to intrauterine hypoxia and vertical transmission. SARS-CoV-2 might have a greater influence on hearing loss (HL) in newborns during the second and third trimesters of pregnancy. Therefore, all newborns whose mothers had COVID-19 during pregnancy should be evaluated for cochlear function, regardless of whether their mothers were symptomatic at the time of the disease. However, the understanding of this issue is not consistent and remains controversial. Since early identification and intervention of congenital HL are crucial to the language development of newborns, newborns should be provided with audiological evaluation by various approaches, including Tele-audiology, in the COVID-19 era.

Selective Inner Hair Cell Loss in a Neonate Harbor Seal (Phoca vitulina)

Simple Summary

Congenital hearing loss (i.e., hearing impairment present at birth) is recognized in humans and other terrestrial species, but there is a lack of information on congenital malformations and associated hearing loss in pinnipeds (seals, sea lions, and walruses). Baseline knowledge on marine mammal inner ear malformations is essential to differentiate between congenital and acquired abnormalities, which may be caused by infectious agents, age, or anthropogenic interactions, such as noise exposure. Analysis of the cochlea of a neonate harbor seal (Phoca vitulina) revealed bilateral loss of inner hair cells (sensory cells responsible for transducing the auditory signal) while the outer hair cells (sensory cells responsible for sound amplification and frequency selectivity and sensitivity) were intact. The selective inner hair cell loss (up to 84.6% of loss) was more severe in the basal turn, where the high frequencies are encoded. Potential causes and consequences are discussed. This is the first report of a case of selective inner hair cell loss in a marine mammal neonate, likely congenital.

Abstract

Congenital hearing loss is recognized in humans and other terrestrial species. However, there is a lack of information on its prevalence or pathophysiology in pinnipeds. It is important to have baseline knowledge on marine mammal malformations in the inner ear, to differentiate between congenital and acquired abnormalities, which may be caused by infectious pathogens, age, or anthropogenic interactions, such as noise exposure. Ultrastructural evaluation of the cochlea of a neonate harbor seal (Phoca vitulina) by scanning electron microscopy revealed bilateral loss of inner hair cells with intact outer hair cells. The selective inner hair cell loss was more severe in the basal turn, where high-frequency sounds are encoded. The loss of inner hair cells started around 40% away from the apex or tip of the spiral, reaching a maximum loss of 84.6% of hair cells at 80–85% of the length from the apex. Potential etiologies and consequences are discussed. This is believed to be the first case report of selective inner hair cell loss in a marine mammal neonate, likely congenital.

Associations between air pollution exposure and birth defects: a time series analysis

Air pollution is a serious environmental problem in China. Birth defects are particularly vulnerable to outdoor air pollution. Our study was to evaluate the association between short-term exposure to air pollutants and the risk of birth defects. Daily data including the air pollutants, meteorological characteristics, and birth records were obtained in Hefei, China, during January 2013 to December 2016. The findings showed that PM_2.5, PM₁₀, SO₂, NO₂, and O₃ exposures were positively correlated with the risk of birth defects. Maternal exposure to PM_2.5 and SO₂ during the 4th to 13th gestational weeks was observed to have a significant association with the risk of birth defects, with the maximum effect in the 7th or 8th week for PM_2.5 and the maximum effect in the 7th week for SO₂. The positively significant exposure windows were the 4th to 14th weeks for PM₁₀, the 4th to 12th weeks for NO₂, and the 26th to 35th weeks for O₃, respectively. The strongest associations were observed in the 8th week for PM₁₀, the 7th week for NO₂, and in the 31st or 32nd week for O_3. The findings of this study demonstrate that air pollutants increase the risk of birth defects among women during pregnancy in Hefei, China, which provide evidence for improving the health of pregnant women and neonates in developing countries, and uncovered potential opportunities to reduce or prevent birth defects by proactive measures during pregnancy.

Hearing screening outcomes in neonates of SARS-CoV-2 positive pregnant women

OBJECTIVE

The current study aimed to investigate possible association of maternal SARS-CoV-2 with newborn hearing loss. We compared hearing screening outcomes in neonates born to women with positive SARS-CoV-2 PCR test results during pregnancy with healthy controls.

METHODS

Neonates born between April and December 2020 in our hospital to mothers with positive SARS-CoV-2 PCR test results during pregnancy were included in this study. Neonates with risk factors for universal newborn hearing screening (NHS) were excluded. Neonates born to mothers with positive SARS-CoV-2 PCR test results during pregnancy were compared with healthy controls in terms of newborn hearing screening results and independent variables.

RESULTS

Neonates in the COVID-19 group were more likely to have a "refer" result in auditory brainstem responses (ABR) compared with the control group (53/118 and 28/118, respectively; p = 0.001). The second ABR test results did not differ significantly between the groups (p = 0.618). Logistic regression revealed that birth week and type of birth were not associated with the "refer" result. PCR positivity in the second trimester was more likely to produce the "refer" result in the first ABR test (p = 0.014).

CONCLUSION

SARS-CoV-2 PCR positivity in pregnancy is significantly associated with an increased risk of abnormal NHS results. Also, the timing of PCR positivity in pregnancy (trimester) may be related to abnormal NHS results.