Neonatal hearing screening and intervention in resource-limited settings: an overview

Coalition for Global Hearing Health Hearing Care Pathways Working Group: Guidelines for Clinical Guidance for Readiness and Development of Evidence-Based Early Hearing Detection and Intervention Programs

Editor's Note: The following article discusses the timely topic Clinical Guidance in the areas of Evidence-Based Early Hearing Detection and Intervention Programs. This article aims to discuss areas of services needed, guidance to countries/organizations attempting to initiate early hearing detection and intervention systems. Expert consensus and systematic/scoping reviews were combined to produce recommendations for evidence-based clinical practice. In Ear and Hearing, our long-term goal for the Point of View article is to stimulate the field's interest in and to enhance the appreciation of the author's area of expertise. Hearing is an important sense for children to develop cognitive, speech, language, and psychosocial skills. The goal of universal newborn hearing screening is to enable the detection of hearing loss in infants so that timely health and educational/therapeutic intervention can be provided as early as possible to improve outcomes. While many countries have implemented universal newborn hearing screening programs, many others are yet to start. As hearing screening is only the first step to identify children with hearing loss, many follow-up services are needed to help them thrive. However, not all of these services are universally available, even in high-income countries. The purposes of this article are (1) to discuss the areas of services needed in an integrated care system to support children with hearing loss and their families; (2) to provide guidance to countries/organizations attempting to initiate early hearing detection and intervention systems with the goal of meeting measurable benchmarks to assure quality; and (3) to help established programs expand and improve their services to support children with hearing loss to develop their full potential. Multiple databases were interrogated including PubMed, Medline (OVIDSP), Cochrane library, Google Scholar, Web of Science and One Search, ERIC, PsychInfo. Expert consensus and systematic/scoping reviews were combined to produce recommendations for evidence-based clinical practice. Eight essential areas were identified to be central to the integrated care: (1) hearing screening, (2) audiologic diagnosis and management, (3) amplification, (4) medical evaluation and management, (5) early intervention services, (6) family-to-family support, (7) D/deaf/hard of hearing leadership, and (8) data management. Checklists are provided to support the assessment of a country/organization's readiness and development in each area as well as to suggest alternative strategies for situations with limited resources. A three-tiered system (i.e., Basic, Intermediate, and Advanced) is proposed to help countries/organizations at all resource levels assess their readiness to provide the needed services and to improve their integrated care system. Future directions and policy implications are also discussed.

Risk factors and hearing outcomes in infants and young children in KwaZulu-Natal, South Africa

BACKGROUND

 Targeted new-born hearing screening, based on high risk factors is recommended in the absence of universal new-born hearing screening in resource-constrained settings. The relevance of risk factors listed in the guidelines of high-income countries and used by low-middle income countries remains relatively unknown. Risk factors consistent with the epidemiological profile, evolution of risks and disease burden in these countries need to be considered.

OBJECTIVES

 This study aimed to profile the frequency of risk factors and their manifestation in hearing outcomes of young children in the KwaZulu-Natal province of South Africa.

METHOD

 A chart review of N = 1433 patients' archival audiology records was conducted, conveniently sampled from a single tertiary hospital (n = 351), a provincial assessment and therapy centre (n = 649), a university clinic (n = 291), and two schools for the deaf (n = 142).

RESULTS

 Overall, 56% of the participants presented with either a conductive, sensorineural or a mixed hearing loss; 62% of the children had between 1 and 2 risk factors present (Mean [M] = 1.1; standard deviation [s.d.] = 0.98). Admission to neonatal intensive care unit, maternal infections, bacterial and viral infections and chemotherapy, from the Joint Committee on Infant Hearing list of high risk factors were significantly associated with hearing loss (p  0.05). Known non-JCIH risks, emerging risks and other statistically significant contextually relevant risk factors were also noted.

CONCLUSION

 Understanding the profile of high risk factors in a given context has implications for prevention, early hearing identification and intervention services.Contribution: Targeted new-born hearing screening needs to be based on risk factors that are contextually relevant. This study is one of the first profiling high risk factors for hearing loss in children in KZN, the province with the second highest population in South Africa.

Hearing Loss Detection and Early Intervention Strategies in Kenya

Background

Thirty-four million children globally have disabling hearing loss, with the highest prevalence in low- and middle-income countries (LMICs). Early identification and management is crucial, yet barriers to screening and treatment of hearing loss are extensive in LMICs. Unaddressed hearing loss negatively impacts individuals and communities. The WHO's 2021 World Report on Hearing urges the development of Ear and Hearing Care (EHC) programs to improve access to all aspects of care, including screening, diagnostics, management, and developmental support. A joint Nairobi- and Seattle-based group convened in 2021 to discuss strategies for program development in Kenya, as presented in this paper.

Findings

Developing a national EHC program must include the necessary support services for a child with a diagnosed hearing loss, while simultaneously promoting engagement of family, community, and healthcare workers. Existing government and healthcare system policies and priorities can be leveraged for EHC programming. Strategies for success include strengthening connections between policymakers at national, county, and municipal levels and local champions for the EHC agenda, with a concurrent focus on policy, early detection and intervention, habilitation, and family-centered care. Updates to health policy and funding to support the accessibility of services and equipment should focus on leveraging national healthcare coverage for hearing technologies and services, strengthening referral pathways, training to bolster the workforce, and metrics for monitoring and evaluation. Additional strategies to support forward progress include strategic engagement of partners and leveraging local partners for phased scale-up.

Conclusions and Recommendations

Recommendations to strengthen EHC within the Kenyan health system include concurrent leverage of existing health policies and priorities, partner engagement, and strengthening referral pathways, monitoring and evaluation, and training. These strategies may be generalized to other countries too.

Time-resolved quantitative proteomic analysis of the developing Xenopus otic vesicle reveals putative congenital hearing loss candidates

Over 200 genes are known to underlie human congenital hearing loss (CHL). Although transcriptomic approaches have identified candidate regulators of otic development, little is known about the abundance of their protein products. We used a multiplexed quantitative mass spectrometry-based proteomic approach to determine protein abundances over key stages of Xenopus otic morphogenesis to reveal a dynamic expression of cytoskeletal, integrin signaling, and extracellular matrix proteins. We correlated these dynamically expressed proteins to previously published lists of putative downstream targets of human syndromic hearing loss genes: SIX1 (BOR syndrome), CHD7 (CHARGE syndrome), and SOX10 (Waardenburg syndrome). We identified transforming growth factor beta-induced (Tgfbi), an extracellular integrin-interacting protein, as a putative target of Six1 that is required for normal otic vesicle formation. Our findings demonstrate the application of this Xenopus dataset to understanding the dynamic regulation of proteins during otic development and to discovery of additional candidates for human CHL.

Parental perceptions to new-born screening for hearing loss in Nigeria: A systematic review

OBJECTIVE

To investigate the perceptions of parents towards universal new-born screening for hearing loss in Nigeria.

METHODS

A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) system. A comprehensive search was undertaken using multiple databases (National Library of Medicine, PubMed, Cochrane Library, Scopus, Google Scholar, and MEDLINE) published in English between 2009 and 2018. The sample size of 10 studies were retrieved by using a predefined inclusion and exclusion criteria, keywords, and Boolean operator search patterns. Data extraction and analysis and quality appraisal of the selected articles was carried out.

RESULTS

80% of the identified studies indicated negative perceptions of Nigerian parents towards new-born hearing loss screening programmes. Possible reasons behind such negative perceptions were categorised into demographic factors, psychological factors, behavioural factors, and service-related factors. Specifically, barriers included low income, misconceptions, mode of delivery, fear of associated risk with screening procedure, preference for traditional medicines, inappropriately designed screening programmes, cost of screening programmes, resource-limited settings, lack of awareness about risk factors and their effects.

CONCLUSION

The research concluded that it is necessary to focus on the range of underlying factors (including awareness and education) contributing in shaping the above mentioned negative perceptions among Nigerian parents. The findings have great implications for the theoretical researchers for developing future research path as well as practical suggestion for authorities in policymaking in the healthcare sector in Nigeria.

Test-Retest repeatability of automated threshold audiometry in Nicaraguan schoolchildren

OBJECTIVE

Automated threshold audiometry (ATA) could increase access to paediatric hearing assessment in low- and middle-income countries, but few studies have evaluated test-retest repeatability of ATA in children. This study aims to analyse test-retest repeatability of ATA and to identify factors that affect the reliability of this method.

DESIGN

ATA was performed twice in a cohort of Nicaraguan schoolchildren. During testing, the proportion of responses occurring in the absence of a stimulus was measured by calculating a stimulus response false positive rate (SRFP). Absolute test-retest repeatability was determined between the two trials, as well as the impact of age, gender, ambient noise, head circumference, and SRFP on these results.

STUDY SAMPLE

807 children were randomly selected from 35 schools in northern Nicaragua.

RESULTS

Across all frequencies, the absolute value of the difference between measurements was 5.5 ± 7.8 dB. 89.6% of test-retest differences were within 10 dB. Intra-class correlation coefficients between the two measurements showed that lower SRFP was associated with improved repeatability. No effect of age, gender, or ambient noise was found.

CONCLUSIONS

ATA produced moderate test-retest repeatability in Nicaraguan schoolchildren. Participant testing behaviours, such as delayed or otherwise inappropriate response patterns, significantly impacts the repeatability of these measurements.

Roles and reported practices of paediatricians in the early identification and monitoring of hearing impairment in high-risk newborns and infants

BACKGROUND

The paediatrician is often the first professional who provides care for the infant and their families, hence having a vital role in the early identification and intervention of hearing impairment.

OBJECTIVE

This study aimed to identify the role and reported practices of paediatricians in the early identification and monitoring of hearing impairment in high-risk newborns and infants.

METHODS

The sample comprised 30 paediatricians in South Africa. Data were collected by means of an online survey and analysed using descriptive statistics.

RESULTS

Variability was noted in the early identification protocols, with most participants conducting objective measures. Although most participants refer newborns and infants for audiological evaluation when hearing impairment is suspected, there is variability with regard to the age at which they are referred. Approximately 98% of participants believe that they form part of the multidisciplinary team; however, only 69% reported that they have actually been part of a multidisciplinary team.

CONCLUSIONS

Paediatricians had sufficient knowledge regarding the assessment of hearing impairment and their role in the early hearing detection and intervention programme. There is however a need for information sharing regarding appropriate hearing screening measures.

School Hearing Screening With a Portable, Tablet-Based, Noise-Attenuating Audiometric Headset in Rural Nicaragua

OBJECTIVE

To investigate the utility and effectiveness of a noise-attenuating, tablet-based mobile health system combined with asynchronous telehealth evaluations for screening rural Nicaraguan schoolchildren for hearing loss.

STUDY DESIGN

Prospective population-based survey.

SETTING

Rural Nicaraguan communities.

PATIENTS

There were 3,398 school children 7 to 9 years of age.

INTERVENTIONS

Diagnostic automated and manual audiometry, detailed asynchronous telehealth evaluations.

MAIN OUTCOME MEASURES

Referral rates, ambient noise levels, and audiometric results as well as hearing loss prevalence, types, and risk factors.

RESULTS

Despite high ambient noise levels during screening (46.7 dBA), no effect of noise on referral rates on automated audiometry or confirmatory manual audiometry in those who failed automated testing was seen. The overall audiometric referral rate was 2.6%. Idiopathic sensorineural hearing loss (SNHL) and cerumen impaction were the most common types of hearing loss in this population with an estimated prevalence of hearing loss (all types) of 18.3 per 1,000 children. SNHL was associated with both drug exposure during pregnancy (p = 0.04) and pesticide exposure in the home (p = 0.03).

CONCLUSION

Hearing screening using a tablet-based, noise-attenuating wireless headset audiometer is feasible and effective in rural low-resource environments with moderately elevated ambient noise levels. The referral rate with noise-attenuating headsets was much lower than that previous reports on this population. In addition, manual audiometry resulted in much lower referral rates than automated audiometry. The confirmed hearing loss rate in this study is comparable to reports from other low-income countries that use some form of noise attenuation during screening. Pesticide exposure and drug exposure during pregnancy are potential causes of SNHL in this population.

Concurrent Hearing and Genetic Screening among Newborns in Ningbo, China

OBJECTIVE

To detect the carrier rates of deafness gene variants in populations in Ningbo and analyze the risk of hereditary hearing loss through concurrent hearing and genetic screening tests.

METHODS

Two thousand one hundred and seventy-four newborns were enrolled from November 2018 to August 2019. All subjects underwent hearing screening and newborn deafness genetic screening with 15 variants in 4 genes, and the positive sites were simultaneously verified by sequencing.

RESULTS

The total carrier rate of genetic variants in Ningbo reached 4.32%, when GJB2 c.235delC was the variant with the highest prevalence (2.12%), approximately accounting for 48.9% of the total carrier frequency. The carrier frequency of SLC26A4 c.919-2A>G was 0.87%, while the most common variant in mitochondrial DNA (mtDNA) MT-RNR1 gene was m.1555A>G, and its carrier frequency was 0.184%. In the OAE testing, 92 newborns passing hearing screening were tested positively for variants in 4 genes, and 2 of 42 newborns who failed in the first hearing test were found to mutate in 4 genes.

CONCLUSION

Herein, the results concerning the carrier rates for deafness gene mutations of Ningbo population are reported. Our study is beneficial to the insight into the deafness genomic epidemiology for deafness genes in Ningbo population and provides the reference for healthcare in Ningbo.

Newborn Hearing Screening Benefits Children, but Global Disparities Persist

There is substantial evidence that newborn hearing screening (NHS) reduces the negative sequelae of permanent childhood hearing loss (PCHL) if performed in programs that aim to screen all newborns in a region or nation (often referred to as Universal Newborn Hearing Screening or UNHS). The World Health Organization (WHO) has called in two resolutions for the implementation of such programs and for the collection of large-scale data. To assess the global status of NHS programs we surveyed individuals potentially involved with newborn and infant hearing screening (NIHS) in 196 countries/territories (in the following text referred to as countries). Replies were returned from 158 countries. The results indicated that 38% of the world's newborns and infants had no or minimal hearing screening and 33% screened at least 85% of the babies (hereafter referred to as UNHS). Hearing screening programs varied considerably in quality, data acquisition, and accessibility of services for children with PCHL. In this article, we summarize the main results of the survey in the context of several recent WHO publications, particularly the World Report on Hearing, which defined advances in the implementation of NHS programs in the Member States as one of three key indicators of worldwide progress in ear and hearing care (EHC).

Prevalence, risk factors, and audiological characteristics of auditory neuropathy

OBJECTIVE

The objective of this study was to determine the prevalence, risk factors, and audiological characteristics of auditory neuropathy spectrum disorder (ANSD) in the pediatric population.

DESIGN

A retrospective review of medical charts was conducted for children visiting two hospitals in Saudi Arabia.

STUDY SAMPLE

Medical records of 1025 patients with sensorineural hearing loss (SNHL) were reviewed. We analyzed the databases for results of audiological examinations, risk factors, and outcomes of intervention including hearing aid (HA) and cochlear implantation (CI).

RESULTS

Out of 1025 children with SNHL, 101 patients (9.85%) were identified to have ANSD. Audiological characteristics of the ANSD group revealed a severe-to-profound degree of hearing loss, all showed type A tympanogram and absent reflexes, absent auditory brainstem response (ABR) findings with present cochlear microphonic while otoacoustic emissions were absent in 54.5% of patients. The most prevalent risk factors for ANSD in this group were family history of hearing loss, consanguinity, hyperbilirubinemia, and low birth weight. Pure tone and speech detection thresholds improved significantly with CI compared to HA use in this sample of patients with ANSD.

CONCLUSION

This study shows that ANSD is not extremely rare among Saudi children with severe to profound hearing loss, with a prevalence of 9.85%.

Speech Recognition in Noise Using Binaural Diotic and Antiphasic Digits-in-Noise in Children: Maturation and Self-Test Validity

BACKGROUND

 Digits-in-noise (DIN) tests have become popular for hearing screening over the past 15 years. Several recent studies have highlighted the potential utility of DIN as a school-aged hearing test. However, age may influence test performance in children due to maturation. In addition, a new antiphasic stimulus paradigm has been introduced, allowing binaural intelligibility level difference (BILD) to be measured by using a combination of conventional diotic and antiphasic DIN.

PURPOSE

 This study determined age-specific normative data for diotic and antiphasic DIN, and a derived measure, BILD, in children. A secondary aim evaluated the validity of DIN as a smartphone self-test in a subgroup of young children.

RESEARCH DESIGN

 A cross-sectional, quantitative design was used. Participants with confirmed normal audiometric hearing were tested with a diotic and antiphasic DIN. During the test, arrangements of three spoken digits were presented in noise via headphones at varying signal-to-noise ratio (SNR). Researchers entered each three-digit spoken sequence repeated by the participant on a smartphone keypad.

STUDY SAMPLE

 Overall, 621 (428 male and 193 female) normal hearing children (bilateral pure tone threshold of ≤ 20 dB hearing level at 1, 2, and 4 kHz) ranging between the ages of 6 and 13 years were recruited. A subgroup of 7-year-olds (n = 30), complying with the same selection criteria, was selected to determine the validity of self-testing.

DATA COLLECTION AND ANALYSIS

 DIN testing was completed via headphones coupled to a smartphone. Diotic and antiphasic DIN speech recognition thresholds (SRTs) were analyzed and compared for each age group. BILD was calculated through subtraction of antiphasic from diotic SRTs. Multiple linear regressions were run to determine the effect of age on SRT and BILD. In addition, piecewise linear regressions were fit across different age groups. Wilcoxon signed-rank tests were used to determine differences between self- and facilitated tests.

RESULTS

 Age was a significant predictor, of both diotic and antiphasic DIN SRTs (p < 0.05). SRTs improved by 0.15 dB and 0.35 dB SNR per year for diotic and antiphasic SRTs, respectively. However, age effects were only significant up to 10 and 12 years for antiphasic and diotic SRTs, respectively. Age significantly (p < 0.001) predicted BILD, which increased by 0.18 dB per year. A small SRT advantage for facilitated over self-testing was seen but was not significant (p > 0.05).

CONCLUSIONS

 Increasing age was significantly associated with improved SRT and BILD using diotic and antiphasic DINs. DIN could be used as a smartphone self-test in young children from 7 years of age with appropriate quality control measures to avoid potential false positives.

Surviving and Thriving: Early Intervention for Neonatal Survivors With Developmental Disability in Uganda

Global attention on early child development, inclusive of those with disability, has the potential to translate into improved action for the millions of children with developmental disability living in low- and middle-income countries. Nurturing care is crucial for all children, arguably even more so for children with developmental disability. A high proportion of survivors of neonatal conditions such as prematurity and neonatal encephalopathy are affected by early child developmental disability. The first thousand days of life is a critical period for neuroplasticity and an important window of opportunity for interventions, which maximize developmental potential and other outcomes. Since 2010, our group has been examining predictors, outcomes, and experiences of neonatal encephalopathy in Uganda. The need for an early child intervention program to maximize participation and improve the quality of life for children and families became apparent. In response, the "ABAaNA early intervention program," (now re-branding as 'Baby Ubuntu') a group participatory early intervention program for young children with developmental disability and their families, was developed and piloted. Piloting has provided early evidence of feasibility, acceptability, and impact and a feasibility trial is underway. Future research aims to develop programmatic capacity across diverse settings and evaluate its impact at scale.

Screening Programs for Hearing Assessment in Newborns and Children

Objective In this study, we aimed to assess the incidence of hearing loss in the pediatric population through otoacoustic emission (OAE) and brainstem evoked response audiometry (BERA) and to analyze the possible etiological factors responsible for it. Material and methods A retrospective observational study was conducted in the Otolaryngology (ENT) and Gynecology and Obstetrics Departments at the Jinnah Postgraduate Medical Centre and National Institute of Child Health in Karachi, Pakistan between July 2019 and October 2019. The convenient sampling technique was used to select the patients. The final sample size consisting of newborns and children was 108. Initially, screening procedures were undertaken for newborns to detect permanent or fluctuating, bilateral or unilateral, and sensory or conductive hearing loss, averaging 30-40 dB or more in the frequency region, which indicated potential issues related to speech recognition (approximately 500-4,000 Hz). The screening of newborns involved the use of non-invasive, objective physiologic measures that included OAEs and/or auditory brainstem response (ABR). The children with hearing impairment then underwent BERA; thereafter, further investigations were performed to confirm the defects found on BERA testing. Results Of the 108 cases, 96 had normal hearing on OAE screening, and 12 were found to have hearing loss on the OAE test. Further testing was carried out on BERA for 12 cases that had been detected to have hearing loss on OAE, and BERA showed normal hearing for five cases whereas seven were found to have hearing loss. Of the seven patients with hearing loss on the BERA test, five were diagnosed with cochlear deafness, and two had retrocochlear deafness. Conclusion Our present study concludes that in order to avoid any hearing problems in infants, OAE hearing screening and diagnostic BERA screening programs should be carried out in all the hospitals of Pakistan to assess newborn hearing at an early age.

Current status of universal newborn hearing screening program at 26 institutions in China

OBJECTIVES

The present study aimed to determine the status of a universal newborn hearing screening (UNHS) program being conducted in parts of China, by comparing differences in the program findings between 2016 and 2017, as well as across regions in China.

METHODS

This study investigated a nationally representative sample of newborns from 26 provinces, autonomous regions, and municipalities in mainland China. A ''Newborn Hearing Screening Survey'' questionnaire was sent to 43 hearing screening institutions throughout China and the data were analyzed, with appropriate quality control throughout the study process.

RESULTS

Twenty-six questionnaires, covering 55.88% (19/34) of the provincial administrative regions in China were appropriately completed. The overall sampling frame comprised 238,795 (year 2016) and 229,185 (year 2017) newborns, respectively. We found differences between two years, the initial screening coverage in 2017 (96.10%) was higher than that in 2016 (94.96%); the referral rate at initial screening in 2017 (9.21%) was lower than that in 2016 (10.26%); and the rescreening rate in 2017 (73.50%) was higher than that in 2016 (68.44%). We found differences across three regions, the rescreening rate were highest in West China, the referral rate at rescreening and the referral rate to diagnostic audiological assessment diagnosis were both highest, while the hearing-loss rate was lowest, in the East China in two years. Overall, 61.54% (n = 16) reported using otoacoustic emissions (OAEs), while 38.46% (n = 10) reported using OAEs in combination with automated auditory brainstem response (AABR) tests, for the initial screening. For rescreening, most sites (n = 19, 73.08%) reported using OAEs in combination with AABR, followed by OAEs only (n = 4, 15.38%) and AABR only (n = 3, 11.54%). Of the twenty-six institutions, 57.69% (n = 15) were equipped with a digital information management system for UNHS program, East China had the highest rate of it (81.82%, 9/11).

CONCLUSIONS

This study indicated that implementation of a UNHS program had essentially been achieved in many regions of China under the guidance of technical specifications for newborn hearing screening. Compared with 2016, the overall quality of the UNHS program had improved in 2017 and that in East China was better than in the Midland and West China. However, national quality control of the UNHS program is still required to enhance the quality of the program and public education needs to be emphasized to improve the rescreening and reception rate.

Maternal knowledge and views regarding early hearing detection and intervention in children aged 0-5 years at a semi-urban primary care clinic in South Africa

BACKGROUND

South Africans have an increasing burden of hearing loss, especially in low-income rural areas. Limited information is available regarding caregivers' knowledge and views regarding infant hearing loss, which is essential for the successful implementation of early hearing detection and intervention (EHDI) programmes.

OBJECTIVES

The main aim of the study was to describe the knowledge and views of mothers with children aged between 0 and 5 years old regarding hearing screening, risk factors, symptoms of hearing loss, and intervention options for hearing loss.

METHOD

A survey was employed at a primary care clinic to gain insight into the maternal views on hearing loss and early intervention services for children aged 0-5 years old.

RESULTS

The majority (83.2%) of the mothers believed that hearing can be tested at birth, 90.7% believed in the biomedical model of intervention which is based on cure, prevention, and pathology as opposed to traditional or alternative medicinal beliefs, and 95.3% indicated that they would seek medical attention if they noticed symptoms of hearing loss. Consequences of hearing loss, such as academic, communication and social problems, were indicated by 65.4% of mothers.

CONCLUSION

The findings demonstrated that although cultural beliefs regarding superstitious causes of hearing loss and use of traditional medicine exist, satisfactory maternal knowledge regarding detection and intervention for hearing loss is present. Maternal views are favourable and a general willingness to participate in EHDI programmes was present. This study advocates for the implementation of EHDI programmes at all primary healthcare clinics across South Africa.

Fetal antisense oligonucleotide therapy for congenital deafness and vestibular dysfunction

Disabling hearing loss impacts ∼466 million individuals worldwide with 34 million children affected. Gene and pharmacotherapeutic strategies to rescue auditory function in mouse models of human deafness are most effective when administered before hearing onset, after which therapeutic efficacy is significantly diminished or lost. We hypothesize that preemptive correction of a mutation in the fetal inner ear prior to maturation of the sensory epithelium will optimally restore sensory function. We previously demonstrated that transuterine microinjection of a splice-switching antisense oligonucleotide (ASO) into the amniotic cavity immediately surrounding the embryo on embryonic day 13-13.5 (E13-13.5) corrected pre-mRNA splicing in the juvenile Usher syndrome type 1c (Ush1c) mouse mutant. Here, we show that this strategy only marginally rescues hearing and partially rescues vestibular function. To improve therapeutic outcomes, we microinjected ASO directly into the E12.5 inner ear. A single intra-otic dose of ASO corrects harmonin RNA splicing, restores harmonin protein expression in sensory hair cell bundles, prevents hair cell loss, improves hearing sensitivity, and ameliorates vestibular dysfunction. Improvements in auditory and vestibular function were sustained well into adulthood. Our results demonstrate that an ASO pharmacotherapeutic administered to a developing organ system in utero preemptively corrects pre-mRNA splicing to abrogate the disease phenotype.

Reliability of Tablet-based Hearing Testing in Nicaraguan Schoolchildren: A Detailed Analysis

OBJECTIVE

Determine whether an electronic tablet-based Wireless Automated Hearing-Test System can perform high-quality audiometry to assess schoolchildren for hearing loss in the field in Nicaragua.

STUDY DESIGN

Cross-sectional.

SETTING

A school and hospital-based audiology clinic in Jinotega, Nicaragua.

SUBJECTS AND METHODS

Second and third graders (n = 120) were randomly selected for hearing testing in a school. Air conduction hearing thresholds were obtained bilaterally using a Wireless Automated Hearing-Test System at 1000, 2000, and 4000 Hz. Referral criteria were set at more than 25 dBHL at one or more frequencies. A cohort of children was retested with conventional audiometry in a hospital-based sound booth. Factors influencing false-positive examinations, including ambient noise and behavior, were examined.

RESULTS

All children with hearing loss were detected using an automated, manual, or two-step (those referred from automated testing were tested manually) protocol in the school (sensitivity = 100%). Specificity was 76% for automated testing, 97% for manual testing, and 99% for the two-step protocol. The variability between thresholds obtained with automated testing was greater than manual testing when compared with conventional audiometry. The percentage of participant responses when no stimulus tone was presented during automated testing was higher in children with false-positive examinations.

CONCLUSION

A Wireless Automated Hearing-Test System identified all children with hearing loss in a challenging field setting. A two-step protocol (those referred from automated testing are tested manually) reduced false-positive examinations and unnecessary referrals. Children who respond frequently when no tone is presented are more likely to have false-positive automated examinations and should be tested manually.

Mutation analysis of the SLC26A4 gene in three Chinese families

In order to investigate the genetic causes of hearing loss in a Chinese proband (in Family A) with enlarged vestibular aqueduct (EVA) and to investigate the genotype of two Chinese probands with SLC26A4 singe-allelic mutation and normal hearing (in Families B and C, respectively), the three probands and their parents were clinically and genetically evaluated. Twenty exons and flanking splice sites of the SLC26A4 gene were screened for pathogenic mutations via amplification with PCR and bidirectional sequencing. As controls, a group of 400 healthy newborns from the same ethnic background underwent SLC26A4 gene screening using the same method. The three probands all harbored two mutations in the SLC26A4 gene in the form of compound heterozygosity. The genotypes of mutations in Families A, B, and C are c.1211C>A/c.919-2A>G, c.1729G>A/c.919-2A>G, and c.1286C>A/c.919-2A>G, respectively. The missense mutations c.1211C>A (p.T430Q) in exon 10 and c.1729G>A (p.V577I) in exon 16 are both reported for the first time and were absent in 400 healthy newborns. c.1211C>A has Glutamine (Gln) at amino acid 430 instead of Threonine (Thr), and c.1729G>A has Isoleucine (Ile) at amino acid 577 instead of Valine (Val). c.1286C>A, a mutation previously reported in DVD and HGMD, was associated with Mondini deformity, but a proband with the c.1286C>A mutation in this study was normal. This study has demonstrated that the novel missense mutation c.1211C>A in compound heterozygosity with c.919-2A>G in the SLC26A4 gene is likely to be the cause of deafness in Family A. A novel variant, c.1729G>A, was identified and is likely benign. The pathogenicity of the c.1286C>A mutation warrants more in-depth study. These findings will broaden the spectrum of known SLC26A4 mutations in the Chinese population, providing more information for genetic counseling and diagnosis of hearing loss with EVA.

Prevalence of Severe and Profound Sensorineural Hearing Loss in School Children in West Bengal, India

There is pressing need for reliable information about prevalence of sensorineural hearing loss in children in India. Without this basic information it is difficult to plan services on a rational basis. In this stratified cross sectional study, we aimed to determine the prevalence of severe and profound sensorineural hearing loss in school children in West Bengal, India. We hypothesized that all children with severe or profound hearing loss in elementary schools (age 6-14 years) would be among those identified as 'children with special need' because of their marked problems with hearing, speech or communication. First stratum of our study included all 6-14 years old mainstream elementary school 'children with special need', with known or suspected hearing problem. Second stratum covered all 6-14 years old hearing impaired children attending special schools. Comprehensive audiological assessment of 10,763 'children with special need' in mainstream elementary schools identified 3984 children showing severe or profound SNHL (≥71 dB). A further 1022 children were identified with similar loss in special schools, giving a total of 5006 children with severe or profound sensorineural loss among a school population of 8,654,057, with estimated prevalence of 0.58 (CI 0.57-0.59) per 1000 children. This is the first large scale study of the epidemiology of severe and profound sensorineural hearing loss in school children in India. Although further studies are needed from other parts of India, in the interim, findings of this study can form the basis for planning resource allocation, service provision, investigation into etiology and prevention of sensorineural deafness in children in India.

Genotyping and audiological characteristics of infants with a single-allele SLC26A4 mutation

OBJECTIVES

To identify second-allele variant in infants with a known single-allele mutation of the SLC26A4 gene and to determine the frequency of their occurrence; and to investigate the clinical audiological characteristics of infants with bi-allelic mutations in SLC26A4.

METHODS

The study subjects were 371 patients with a single-allele SLC26A4 mutation detected by neonatal deafness gene screening (4 genes and 9 pathogenic variants) who were treated at the otology outpatient department of Beijing Tongren Hospital. The exonic and flanking splice site regions of the SLC26A4 gene were sequenced for all patients. All patients with bi-allelic SLC26A4 mutations underwent audiological evaluation, and some also underwent temporal bone computed tomography and/or inner ear magnetic resonance imaging.

RESULTS

Of the 371 patients, 314 (84.64%) had an c.919-2A > G heterozygous mutation and 57 (15.36%) had a c.2168A > G (p.H723R) heterozygous mutation. 13 patients (3.50%) had a second-allele variant, including 11 (2.96%) with pathogenic mutations and 1 (0.27%) with a likely benign variant. Of the 13 patients with bi-allelic mutations, 11 had hearing loss and 2 had normal hearing, the latter of whom had c.919-2A > G/c.1766A > G and c.919-2A > G/c.757A > G compound heterozygous mutations, respectively. Four of the 13 patients with bi-allelic mutations had passed the universal newborn hearing screening, including 2 cases (15.38%) with hearing loss. The most prevalent degree of hearing loss was profound (40.91%), followed by severe (36.36%). The most prevalent audiometric configuration was sloping hearing loss (50.00%), followed by flat-type hearing loss (40.91%).

CONCLUSIONS

This is the first report in China of the frequency of occurrence of second-allele variant in infants with a known single-allele mutation of the SLC26A4 gene; the frequency was 3.50% for any type of variant and 2.96% for pathogenic mutations. A novel variant, c.1766A > G (p.Q589R), which is likely benign, was identified. The pathogenicity of c.757A > G (p.I253V) mutation deserves more in-depth research. For infants with bi-allelic SLC26A4 mutations, the degree of hearing loss was mainly severe-to-profound and the audiometric configuration was mainly sloping.

Tablet-based tele-audiometry: Automated hearing screening for schoolchildren

Introduction

To assess the performance of a tablet-based tele-audiometry method for automated hearing screening of schoolchildren through a comparison of the results of various hearing screening approaches.

Methods

A total of 244 children were evaluated. Tablet-based screening results were compared with gold-standard pure-tone audiometry. Acoustic immittance measurements were also conducted. To pass the tablet-based screening, the children were required to respond to at least two out of three sounds for all the frequencies in each ear. Several hearing screening methods were analysed: exclusively tablet-based (with and without 500 Hz checked) and combined tests (series and parallel). The sensitivity, specificity, positive and negative predictive values and accuracy were calculated.

Results

A total of 9.43% of children presented with mild to moderate conductive hearing loss (unilateral or bilateral). Diagnostic values varied among the different hearing screening approaches that were evaluated: sensitivities ranged from 60 to 95%, specificities ranged from 44 to 91%, positive predictive values ranged from 15 to 44%, negative predictive values ranged from 95 to 99%, accuracy values ranged from 49 to 88%, and area under curve values ranged from 0.690 to 0.883. Regarding diagnostic values, the highest results were found for the tablet-based screening method and for the series approach.

Discussion

Compared with the results obtained by conventional audiometry and considering the diagnostic values of the different hearing screening approaches, the highest diagnostic values were generally obtained using the automated hearing screening method (including 500 Hz). Thus, this application, which was developed for the tablet computer, was shown to be a valuable hearing screening tool for use with schoolchildren. Therefore, we suggest that this hearing screening protocol has the potential to improve asynchronous tele-audiology service delivery.

Neurodevelopmental outcomes for high-risk neonates in a low-resource setting

Worldwide, most neonates who survive prematurity and serious illness reside in low-resource settings where developmental outcome data and follow-up care are limited. This study aimed to assess in Fiji, a low-resource Pacific setting, prevalence and risk factors for moderate to severe neurodevelopmental impairment (NDI) in early childhood among high-risk neonates compared with controls. Retrospective cohort study comparing long-term outcomes for high-risk neonatal intensive care unit patients (n=149) compared with matched term, normal birth weight neonates (n=147) discharged from Colonial War Memorial Hospital between November 2008 and April 2010. NDI was defined as one or more of cerebral palsy, moderate to severe hearing or visual impairment, or global developmental delay using Bayley Scales of Infant and Toddler Development Third Edition (ie, score <70 in ≥1 of cognitive, language or motor domains). At median (IQR) age 36.1 (28.3, 38.0) months, prevalence of moderate to severe NDI % (95% CI, n) in high-risk and control groups was 12 (5 to 17, n=13) and 5 (2 to 12, n=5), respectively, an increased risk ratio (95% CI) of 2.7 (0.8 to 8.9). Median gestational age (weeks (median, IQR)) in the high-risk group was 37.5 (34-40) weeks. Among high-risk neonates, gestational age, birth weight, asphyxia, meningitis and/or respiratory distress were significantly associated with risk of NDI. Prevalence of NDI was high among this predominantly term high-risk neonatal cohort compared with controls. Results, including identified risk factors, inform efforts to strengthen quality of care and models of follow-up for high-risk neonates in this low-resource setting.

Determinants of caregivers' awareness of Universal Newborn Hearing Screening in Malaysia

OBJECTIVE

This paper aims to investigate the effects of perceived attitude and anxiety on awareness of UNHS among caregivers in Malaysia.

METHODS

Using cross sectional research approach, data were collected and some 46 out of 87 questionnaires distributed to caregivers attending UNHS programs at selected public hospitals were usable for analysis (response rate of 52.8%). Partial Least Squares Method (PLS) algorithm and bootstrapping technique were employed to test the hypotheses of the study.

RESULTS

R square value is 0.205, and it implies that exogenous latent variables explained 21% of the variance of the endogenous latent variable. This value indicates moderate and acceptable level of R-squared values. Findings from PLS structural model evaluation revealed that anxiety has no significant influence (β = -0.091, t = 0.753, p > 0.10) on caregivers' awareness; but perceived attitude has significant effect (β = -0.444, t = 3.434, p < 0.01) on caregivers' awareness.

CONCLUSION

Caregivers' awareness of UNHS is influenced by their perceived attitude while anxiety is not associated with caregivers' awareness. This implies that caregivers may not believe in early detection of hearing impairment in children, thinking that their babies are too young to be tested for hearing loss. Moreover, socio-economic situation of the caregivers may have contributed to their failure to honor UNHS screening appointments as some of them may need to work to earn a living while some may perceive it a waste of time honoring such appointments. Non-significant relationship between anxiety and caregivers' awareness may be due to religious beliefs of caregivers. Limitations and suggestions were discussed.

Knowledge and Cultural Beliefs of Mothers Regarding the Risk Factors of Infant Hearing Loss and Awareness of Audiology Services

The aim of the paper is to describe the knowledge of mothers in Durban, South Africa, regarding risk factors of hearing loss in infants and their awareness of audiology services, and to describe their cultural beliefs about the risk factors for hearing loss in infants. A descriptive survey design with quantitative methods of analysis were used. Conveniently sampled mothers (n=102) receiving postnatal care for their infants from eight provincial clinics within Durban consented to participate, yielding a response rate of 48%. A questionnaire was used to collect the data and the Cronbach α was calculated yielding a score of 0.835, indicating good internal consistency and reliability of the questionnaire. Sixty percent of the mothers were aware of risk factors, such as middle ear infections, ototoxic medication and consumption of alcohol during pregnancy. Seventy percent were unaware that NICU/mechanical ventilation for more than 5 days, prematurity, rubella and jaundice are considered risk factors for hearing loss, implying a need to create awareness amongst mothers regarding such risk factors. Sixty percent (n=62) believed that bewitchment and ancestral curses can cause hearing loss. Cultural beliefs were associated with hearing loss, therefore, health professionals need to demonstrate cultural competence when providing audiology services, especially in a culturally and linguistically diverse countries such as South Africa. Although the mothers had an average knowledge about risk factors, two thirds did not know which professional to seek help from. There is a need to create awareness amongst mothers regarding the risk factors of infant hearing loss as well as audiology services in order to facilitate early detection and intervention. There is a need for health professionals to demonstrate cultural competence when working with their patients.

A national survey of knowledge, attitude and practices among pediatricians towards newborn hearing screening in India

INTRODUCTION

Pediatricians have a key role in ensuring that infant has undergone hearing screening and required follow-up. Attempts in various countries and centers have been made at exploring their knowledge, attitude and practices towards universal newborn hearing screening. In India, such a program is at its preliminary stage, and hence a need was felt to study this aspect in pediatricians working in India.

METHOD

A cross-sectional online survey was carried out among 112 pediatricians working in India. The questionnaire was framed after reviewing the existing questionnaires. Descriptive statistics was used to summarize the findings.

RESULTS

A response rate of 7.99% (112/1402) was obtained of which only 20.5% reported of availability of screening program in their work set-up. The majority of the pediatricians (95%) were aware of the newborn hearing screening while 98.3% were affirmative about the importance of screening of all infants. Very few pediatricians reported of a screening program in their set-up or in their close locality. Overall the pediatricians were confident about their knowledge on this topic yet expressed a need to know more about several intricacies about hearing screening. The pediatricians also provided an input on the most preferred method of receiving more information.

SUMMARY AND CONCLUSION

The success of the universal newborn hearing screening program lies in the support and cooperation of health care providers such as pediatricians. The present study draws attention to the positive attitude and practices exhibited by them. It also sheds light on the knowledge gaps that are present and need the due attention of the policy makers. Further, it highlights the need for having more continuing medical education program and awareness drives for ensuring a better implementation of UNHS.

Universal newborn hearing screening: methods and results, obstacles, and benefits

The incidence of sensorineural hearing loss ranges from 1 to 3 per 1,000 live births in term healthy neonates, and 2-4 per 100 in high-risk infants, a 10-fold increase. Early identification and intervention with hearing augmentation within 6 mo yields optimal effect. If undetected and without treatment, significant hearing impairment may negatively impact speech development and lead to disorders in psychological and mental behaviors. Hearing screening programs in newborns enable detection of hearing impairment in the first days after birth. Programs to identify hearing deficit have significantly improved over the two decades, and their implementation continues to grow throughout the world. Initially based on risk factors, these programs identified only 50-75% of infants with hearing loss. Current recommendations are to conduct universal hearing screening in all infants. Techniques used primarily include automated auditory brainstem responses and otoacoustic emissions that provide noninvasive recordings of physiologic auditory activity and are easily performed in neonates and infants. The aim of this review is to present the objectives, benefits, and results of newborn hearing screening programs including the pros and cons of universal vs. selective screening. A brief history and the anticipated future development of these programs will also be discussed.

Dual sensory impairment in special schools in South-Eastern Nigeria

In a cross-sectional study to determine the magnitude of dual sensory impairment (DSI-combined hearing and vision loss) in children in single-disability special education schools, children in schools for the blind and schools for the deaf in four states in South-East Nigeria were examined by an ophthalmologist and otorhinolaryngologist to determine the level of their disability and to identify other disabilities if any. Participants were all students with childhood blindness or childhood deafness. The magnitude and causes of DSI and the burden of undetected DSI were the main outcome measures. A total of 273 students were examined. About 7% of these students had DSI out of which over 60% (12/19) was previously undetected. There was more DSI in the blind schools than in the deaf schools (p=0.003). There is a large burden of undetected DSI in children in special schools in Nigeria. There is a need to create awareness of this problem and advocate appropriate screening, rehabilitative and educational strategies for children who have it.

Access to cochlear implants: Time to reflect

Cochlear implant (CI) intervention is expensive and accessed mainly by developed countries. The introduction of Universal Newborn Hearing Screening and funding via a public health service give children better access to CIs. However for adults large disparities exist between utilization and estimated prevalence. In the UK CI selection criteria are restrictive compared with many other countries. Improved audiological awareness and screening programmes for adults would improve access to hearing technologies that would improve health and quality of life. Hearing loss itself has significant medical and financial burdens on society and by investing in early intervention and using best technology this would mitigate some of the rising associated medical costs.

Validated Smartphone-Based Apps for Ear and Hearing Assessments: A Review

BACKGROUND

An estimated 360 million people have a disabling hearing impairment globally, the vast majority of whom live in low- and middle-income countries (LMICs). Early identification through screening is important to negate the negative effects of untreated hearing impairment. Substantial barriers exist in screening for hearing impairment in LMICs, such as the requirement for skilled hearing health care professionals and prohibitively expensive specialist equipment to measure hearing. These challenges may be overcome through utilization of increasingly available smartphone app technologies for ear and hearing assessments that are easy to use by unskilled professionals.

OBJECTIVE

Our objective was to identify and compare available apps for ear and hearing assessments and consider the incorporation of such apps into hearing screening programs.

METHODS

In July 2015, the commercial app stores Google Play and Apple App Store were searched to identify apps for ear and hearing assessments. Thereafter, six databases (EMBASE, MEDLINE, Global Health, Web of Science, CINAHL, and mHealth Evidence) were searched to assess which of the apps identified in the commercial review had been validated against gold standard measures. A comparison was made between validated apps.

RESULTS

App store search queries returned 30 apps that could be used for ear and hearing assessments, the majority of which are for performing audiometry. The literature search identified 11 eligible validity studies that examined 6 different apps. uHear, an app for self-administered audiometry, was validated in the highest number of peer reviewed studies against gold standard pure tone audiometry (n=5). However, the accuracy of uHear varied across these studies.

CONCLUSIONS

Very few of the available apps have been validated in peer-reviewed studies. Of the apps that have been validated, further independent research is required to fully understand their accuracy at detecting ear and hearing conditions.

Newborn hearing screening at a community-based obstetric unit: Screening and diagnostic outcomes

OBJECTIVE

Postnatal visits at community-based midwife obstetric units (MOUs) have been proposed as an alternative primary healthcare screening platform in South Africa. This study evaluated the outcomes of distortion product otoacoustic emissions (DPOAEs) and automated auditory brainstem response (AABR) screening conducted by a dedicated non-professional screener at a community-based MOU in the Western Cape, South Africa.

METHODS

Universal newborn hearing screening (UNHS) at a community-based MOU was evaluated over a 16-month period. A dedicated non-professional screener was trained to follow a two-stage screening protocol targeting bilateral hearing loss. A two group comparative design was used alternating AABR (Maico MB11 BERAphone™()) and DPOAE (Bio-logic AuDX I) technology on a daily basis. Infants referring the initial screen received a follow-up appointment in two days' time and were rescreened with the same technology used at their first screen. Those referring the second stage were booked for diagnostic assessments.

RESULTS

7452 infants were screened including 47.9% (n=3573) with DPOAE and 52.1% (n=3879) with AABR technology. Mean age at first stage screen was 6.1 days. The initial bilateral referral rate was significantly lower for AABR (4.6%) compared to DPOAE (7.0%) and dropped to 0.3% and 0.7% respectively following the second stage screenings. First rescreen and initial diagnostic follow-up rates of 90% and 92.3% were obtained for the DPOAE group and 86.6% and 90% for the AABR group. Follow-up rates showed no significant difference between technology groups. Diagnostic assessment revealed a higher prevalence rate for bilateral SNHL among the AABR group (1/1000) compared to the DPOAE group (0.3/1000). Screening technology had no significant influence on daily screening capacity (23 AABR/day; 24 DPOAE/day).

CONCLUSIONS

Postnatal visits at community-based MOUs create a useful platform for hearing screening and follow-up. AABR technology with negligible disposable costs provides opportunity for AABR screening to be utilised in community-based programmes. AABR screening offers lower initial referral rates and a higher true positive rate compared to DPOAE.

The impact of universal newborn hearing screening on long-term literacy outcomes: a prospective cohort study

OBJECTIVE

To determine whether the benefits of universal newborn hearing screening (UNHS) seen at age 8 years persist through the second decade.

DESIGN

Prospective cohort study of a population sample of children with permanent childhood hearing impairment (PCHI) followed up for 17 years since birth in periods with (or without) UNHS.

SETTING

Birth cohort of 100 000 in southern England.

PARTICIPANTS

114 teenagers aged 13-19 years, 76 with PCHI and 38 with normal hearing. All had previously their reading assessed aged 6-10 years.

INTERVENTIONS

Birth in periods with and without UNHS; confirmation of PCHI before and after age 9 months.

MAIN OUTCOME MEASURE

Reading comprehension ability. Regression modelling took account of severity of hearing loss, non-verbal ability, maternal education and main language.

RESULTS

Confirmation of PCHI by age 9 months was associated with significantly higher mean z-scores for reading comprehension (adjusted mean difference 1.17, 95% CI 0.36 to 1.97) although birth during periods with UNHS was not (adjusted mean difference 0.15, 95% CI -0.75 to 1.06). The gap between the reading comprehension z-scores of teenagers with early compared with late confirmed PCHI had widened at an adjusted mean rate of 0.06 per year (95% CI -0.02 to 0.13) during the 9.2-year mean interval since the previous assessment.

CONCLUSIONS

The benefit to reading comprehension of confirmation of PCHI by age 9 months increases during the teenage years. This strengthens the case for UNHS programmes that lead to early confirmation of permanent hearing loss.

TRIAL REGISTRATION NUMBER

ISRCTN03307358.

Long-term neurodevelopmental outcome in high-risk newborns in resource-limited settings: a systematic review of the literature

BACKGROUND

Improving outcomes beyond survival for high-risk newborns in resource-limited settings is an emerging challenge. Global estimates demonstrate the scale of this challenge and significant gaps in morbidity outcome data in high mortality contexts. A systematic review was conducted to document the prevalence of neurodevelopmental impairment in high-risk newborns who were followed up into childhood in low- and middle-income countries.

METHODS

High-risk newborns were defined as low, very or extremely low birthweight, preterm infants or those surviving birth asphyxia or serious infections. Electronic databases were searched and articles screened for eligibility. Included articles were appraised according to STROBE criteria. Narrative review was performed and median prevalence of key neurodevelopmental outcomes was calculated where data quality allowed.

RESULTS

6959 articles were identified with sixty included in final review. At follow-up in early childhood, median estimated prevalence (inter-quartile range) of overall neurodevelopmental impairment, cognitive impairment and cerebral palsy were: for survivors of prematurity/very low birthweight 21.4% (11.6-30.8), 16.3% (6.3-29.6) and 11.2% (5.9-16.1), respectively, and for survivors of birth asphyxia 34.6% (25.4-51.5), 11.3% (7.7-11.8) and 22.8% (15.7-31.4), respectively. Only three studies reporting outcomes following newborn serious bacterial infections were identified. There was limited reporting of important outcomes such as vision and hearing impairment. Major challenges with standardised reporting of key exposure and developmental outcome variables and lack of control data were identified.

CONCLUSION

Understanding the limitations of the available data on neurodevelopmental outcome in newborns in resource-limited settings provides clear direction for research and efforts to improve long-term outcome in high-risk newborns in these settings.

Societal impact of bilirubin-induced hearing impairment in resource-limited nations

Infants with bilirubin-induced neurologic dysfunction (BIND) are characterized by several developmental disabilities including auditory impairments. This paper explores the societal impact of bilirubin-induced auditory impairments, inclusive of hearing impairments and auditory neuropathy spectrum disorders, on these infants, their families, and on the community in resource-limited countries (per capita income of US$6,000 or less). Auditory impairments have substantial emotional, social, and economic impact on the affected infants, their families and communities. The burden is exacerbated by widespread poverty, unfavorable community attitudes towards disabilities, and lack of requisite health, educational, and social services. Curtailing the incidence of avoidable severe hyperbilirubinemia through proactive and effective management of infants at risk or with severe hyperbilirubinemia is necessary at all levels of healthcare delivery. Early detection and intervention for unavoidable auditory impairments should be widely promoted to provide improved developmental trajectories for the affected infants.

Profound childhood hearing loss in a South Africa cohort: risk profile, diagnosis and age of intervention

OBJECTIVE

To describe profound childhood hearing loss in a South African population of pediatric cochlear implant recipients in terms of risk profile, and age of diagnosis and intervention.

METHODS

A retrospective review of patient files for 264 pediatric cochlear implant recipients from five cochlear implant programs was conducted. Data was captured from 264 eligible subjects, of which all were implanted between 1996 and 2013 and PCEHL was confirmed under the age of 5 years old. Data collected included demographical information, risk factors from case histories, diagnostic test procedures conducted, diagnosis (type, onset and degree of hearing loss) and documented ages of caregiver suspicion, initial diagnosis and intervention.

RESULTS

Risk factors for permanent childhood hearing loss were present in 51.1% of cases, with the most prevalent risks being NICU admittance (28.1%), family history of childhood hearing loss (19.6%) and prematurity (15.1%). An associated syndrome was diagnosed in 10% of children and 23.5% presented with at least one additional developmental condition. Hearing loss for most (77.6%) children was confirmed as congenital/early onset, while 20.3% presented with postnatal onset of hearing loss. ANSD was diagnosed in 5% of children, with admittance to NICU (80%) and hyperbilirubinemia (50%) being the most prevalent risk factors for these cases. Hearing loss was typically diagnosed late (15.3 months), resulting in delayed initial hearing aid fitting (18.8 months), enrollment in early intervention services (19.5 months) and eventual cochlear implantation (43.6 months).

CONCLUSION

Most prevalent risk factors in profound childhood hearing loss were admittance to NICU, family history and prematurity. Diagnosis and intervention was typically delayed predisposing this population to poorer outcomes.

The global burden of disabling hearing impairment: a call to action

At any age, disabling hearing impairment has a profound impact on interpersonal communication, psychosocial well-being, quality of life and economic independence. According to the World Health Organization's estimates, the number of people with such impairment increased from 42 million in 1985 to about 360 million in 2011. This last figure includes 7.5 million children less than 5 years of age. In 1995, a "roadmap" for curtailing the burden posed by disabling hearing impairment was outlined in a resolution of the World Health Assembly. While the underlying principle of this roadmap remains valid and relevant, some updating is required to reflect the prevailing epidemiologic transition. We examine the traditional concept and grades of disabling hearing impairment - within the context of the International Classification of Functioning, Disability and Health - as well as the modifications to grading that have recently been proposed by a panel of international experts. The opportunity offered by the emerging global and high-level interest in promoting disability-inclusive post-2015 development goals and disability-free child survival is also discussed. Since the costs of rehabilitative services are so high as to be prohibitive in low- and middle-income countries, the critical role of primary prevention is emphasized. If the goals outlined in the World Health Assembly's 1995 resolution on the prevention of hearing impairment are to be reached by Member States, several effective country-level initiatives - including the development of public-private partnerships, strong leadership and measurable time-bound targets - will have to be implemented without further delay.

Childhood hearing loss and risk profile in a South African population

OBJECTIVE

To describe the nature of hearing loss and associated risk profile in a South African population of infants and children diagnosed at a pediatric referral clinic.

METHODS

A retrospective review of patient files for a pediatric auditory evoked potential clinic in Pretoria was conducted (January 2007-December 2011). Collected data included demographical information, risk factors from case history questionnaire, diagnosis (type and degree of hearing loss), documented age of caregiver suspicion and age of first diagnosis.

RESULTS

Hearing loss was present in 73% (73/100) of cases evaluated. Permanent hearing losses (SNHL, ANSD and mixed) constituted 76% of losses. Unilateral hearing losses constituted 8% of SNHL and 20% of conductive hearing loss. ANSD was diagnosed in 21.4% and SNHL in 78.6% of permanent non-conductive hearing loss cases. The most prevalent SNHL risk was family history of hearing loss and for ANSD it was admittance to the NICU for more than 5 days. The majority of the sample was diagnosed with a permanent bilateral SNHL and ANSD after 36 months of age (47%) despite 40% already suspected of having a hearing loss before 12 months of age.

CONCLUSIONS

A high prevalence of ANSD was found with preventable risk factors often indicated. Age of diagnosis was significantly delayed, evidencing the lack of early hearing detection services in South Africa. The majority of children were diagnosed at ages precluding optimal benefits from early detection and subsequent intervention.

The impact of early identification of permanent childhood hearing impairment on speech and language outcomes

It is well established that permanent childhood hearing impairment (PCHI) has a detrimental impact on speech and language development. The past two decades have seen the gradual introduction of universal newborn hearing screening (UNHS) programmes coupled with early intervention programmes. We review studies that have capitalised on the advent of newborn hearing screening to assess the impact of early identification of PCHI on language outcomes in deaf children. The research supports the conclusion that, in children with PCHI, newborn hearing screening and early identification lead to beneficial effects on language development, with the most consistent evidence provided for links between early identification of PCHI and positive language outcomes. Future research needs to encompass a wider range of outcomes and to assess the impact of UNHS in adolescents and young adults.