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

[Contextual and individual determinants of use of newborn hearing screening: the Brazilian National Health Survey, 2013]

The current study assessed the effect of contextual and individual determinants of the use of newborn hearing screening in Brazilian state capitals and the Federal District. The conceptual theoretical model proposed by Andersen & Davidson (2014) oriented the analyses using multilevel logistic modeling with data from the Brazilian National Health Survey, 2013. The study population (n = 585) is representative of 230,112 pairs of women/responsible person over 18 years of age and their respective children under 2 years of age. At the contextual level (state capitals and Federal District), the use of newborn hearing screening was determined by the proportion of extremely poor individuals (odds ratio - OR = 0.91; 95% confidence interval - 95%CI: 0.83-0.99) and by monthly coverage of newborn hearing screening (OR = 1.02; 95%CI: 1.01-1.02). At the individual level, use of newborn hearing screening was higher in the maternal age bracket 25 to 39 years, compared to < 25 years. The odds of use of newborn hearing screening were lower in mothers with brown race/color (OR = 0.47; 95%CI: 0.26-0.83) compared to white mothers. As for schooling, complete university education nearly tripled the odds of newborn hearing screening when compared to primary schooling (OR = 2.99; 95%CI: 1.15-7.79). Predominantly private prenatal care increased the odds of using newborn hearing screening by 2.18 times, compared to public prenatal care (OR = 2.18; 95%CI: 1.02-4.64). Effective enforcement of existing hearing health laws and policies and prioritization of primary healthcare and health education practices with a focus on more vulnerable newborns, based on the characteristics identified in this study, are initiatives that can help ensure an equitable social protection system.

Profile of childhood hearing loss in the Western Cape, South Africa

OBJECTIVES

To describe the nature, associated risk factors and age of diagnosis for childhood hearing loss in a South African cohort from the Western Cape Province.

METHODS

A retrospective review of clinical data from children under six years of age with confirmed hearing loss at Red Cross War Memorial Children's Hospital (RCWMCH) was conducted between 1 January 2019 and 31 July 2019. Data collected included demographic information, type and degree of hearing loss, documented risk factors associated with hearing loss, and age of suspicion and diagnosis of hearing loss.

RESULTS

The study sample included 240 children with hearing loss, with a mean age of 42 months (21.8 SD; range 2-72). More than two thirds (68.3%) of the children presented with bilateral hearing loss. The majority presented with conductive hearing loss (64.6%), followed by sensorineural (28.7%) and mixed hearing loss (3.3%) or auditory neuropathy spectrum disorder (3.3%). More than half (51.8%) of the bilateral sensorineural hearing losses were of a profound degree. The most prominent risk factor for conductive hearing loss was otitis media, for sensorineural hearing loss it was a family history of childhood hearing loss, and for auditory neuropathy spectrum disorder it was hyperbilirubinaemia. Approximately one third of patients (27.1%) with sensorineural hearing loss did not have any associated risk factors. The mean age of diagnosis of permanent congenital or early-onset hearing loss was 31.4 months (22.8 SD; range 2-72), with a mean delay of nine months (13.2 SD; range 0-60) between age of suspicion and diagnosis of hearing loss (n = 93).

CONCLUSIONS

The large proportion of preventable hearing losses in this sample highlights the importance of maximising primary health care efforts to treat preventable causes timeously. Age of diagnosis of permanent congenital or early-onset hearing loss was severely delayed undermining prospects of positive outcomes through early intervention. Infant hearing screening services in the public health sector of South Africa should be prioritised alongside primary health care efforts to reduce preventable risks for hearing loss.

Mothers' perspectives of newborn hearing screening programme

Background

Newborn hearing screening programs identifies newborns with hearing loss. The early identification enables prompt intervention through hearing rehabilitation. Accurate knowledge of the program and its benefit will impact on the uptake of the program by the citizenry. We hypothesized that there is a gap in the knowledge of parents on hearing screening and rehabilitation measures in Nigeria.

Aim

To determine the knowledge and perceptions of mothers of newborn children on hearing screening.

Methods

A cross sectional observational study among mothers of newborn children at immunization clinics. Semi structured questionnaire on gestational duration, mode of delivery, birth asphyxia, knowledge on hearing loss and newborn hearing screening were administered.

Results

Participants were 48 mothers with age range from 18 to 42 years. Awareness of newborn hearing screening was poor among the mothers; sources of information on newborn hearing screening were antenatal clinic, mass media and friends. The educational level of the participants had no association with awareness (p = 0.11), but the willingness to accept newborn hearing screening, was associated with socioeconomic status (p = 0.04) and the level of education (p = 0.02). The participants were not aware of factors responsible for hearing loss in childhood.

Conclusion

There is inadequate knowledge about newborn hearing screening and risk factors for infant hearing loss among the mothers, though they demonstrate willingness to accept the newborn hearing screening.

Funding

None declared.

Unconjugated bilirubin induces pyroptosis in cultured rat cortical astrocytes

Background

Bilirubin-induced neurological dysfunction (BIND), a severe complication of extreme neonatal hyperbilirubinemia, could develop into permanent neurodevelopmental impairments. Several studies have demonstrated that inflammation and nerve cell death play important roles in bilirubin-induced neurotoxicity; however, the underlying mechanism remains unidentified.

Methods

The present study was intended to investigate whether pyroptosis, a highly inflammatory form of programmed cell death, participated in the bilirubin-mediated toxicity on cultured rat cortical astrocytes. Further, VX-765, a potent and selective competitive drug, was used to inhibit the activation of caspase-1. The effects of VX-765 on astrocytes treated with bilirubin, including the cell viability, morphological changes of the cell membrane and nucleus, and the production of pro-inflammation cytokines, were observed.

Results

Stimulation of the astrocytes with unconjugated bilirubin (UCB) at the conditions mimicking those of jaundiced newborns significantly increased the activation of caspase-1. Further, caspase-1 activation was inhibited by treatment with VX-765. Compared with UCB-treated astrocytes, the relative cell viability of VX-765-pretreated astrocytes was improved; meanwhile, the formation of plasma membrane pores was prevented, as measured by lactate dehydrogenase release, trypan blue staining, and ethidium bromide (EtBr) uptake. Moreover, DNA fragmentation was partly attenuated and the release of IL-1β and IL-18 was apparently decreased.

Conclusion

Pyroptosis is involved in the process of UCB-induced rat cortical astrocytes’ injury in vitro and may be the missing link of cell death and inflammatory response exacerbating UCB-related neurotoxicity. More importantly, the depression of caspase-1 activation, the core link of pyroptosis, attenuated UCB-induced cellular dysfunction and cytokine release, which might shed light on a new therapeutic approach to BIND.

A Randomized Trial of Phototherapy with Filtered Sunlight in African Neonates

BACKGROUND

Sequelae of severe neonatal hyperbilirubinemia constitute a substantial disease burden in areas where effective conventional phototherapy is unavailable. We previously found that the use of filtered sunlight for the purpose of phototherapy is a safe and efficacious method for reducing total bilirubin. However, its relative safety and efficacy as compared with conventional phototherapy are unknown.

METHODS

We conducted a randomized, controlled noninferiority trial in which filtered sunlight was compared with conventional phototherapy for the treatment of hyperbilirubinemia in term and late-preterm neonates in a large, urban Nigerian maternity hospital. The primary end point was efficacy, which was defined as a rate of increase in total serum bilirubin of less than 0.2 mg per deciliter per hour for infants up to 72 hours of age or a decrease in total serum bilirubin for infants older than 72 hours of age who received at least 5 hours of phototherapy; we prespecified a noninferiority margin of 10% for the difference in efficacy rates between groups. The need for an exchange transfusion was a secondary end point. We also assessed safety, which was defined as the absence of the need to withdraw therapy because of hyperthermia, hypothermia, dehydration, or sunburn.

RESULTS

We enrolled 447 infants and randomly assigned 224 to filtered sunlight and 223 to conventional phototherapy. Filtered sunlight was efficacious on 93% of treatment days that could be evaluated, as compared with 90% for conventional phototherapy, and had a higher mean level of irradiance (40 vs. 17 μW per square centimeter per nanometer, P<0.001). Temperatures higher than 38.0°C occurred in 5% of the infants receiving filtered sunlight and in 1% of those receiving conventional phototherapy (P<0.001), but no infant met the criteria for withdrawal from the study for reasons of safety or required an exchange transfusion.

CONCLUSIONS

Filtered sunlight was noninferior to conventional phototherapy for the treatment of neonatal hyperbilirubinemia and did not result in any study withdrawals for reasons of safety. (Funded by the Thrasher Research Fund, Salt Lake City, and the National Center for Advancing Translational Sciences of the National Institutes of Health; Clinical Trials.gov number, NCT01434810.).