South African adolescents' lived experiences of acquired hearing loss following multidrug-resistant tuberculosis treatment.

Objective: The impact of acquiring hearing loss might be exacerbated during adolescence, as this normal transition from childhood to adulthood is characterised by identity construction and social intensity. This study aimed to describe the lived experiences of South African adolescents with acquired hearing loss following aminoglycoside treatment for multidrug resistant tuberculosis. Design: The study adopted a descriptive phenomenological design and in-depth, semi-structured interviews were conducted in English, isiZulu and Afrikaans. The data was managed and analysed according to a modified version of Hycner's framework. Study sample: Six participants aged 16-24 years with bilateral, mild to profound hearing loss acquired from aminoglycoside treatment were recruited from two South African provinces. Results: Three themes emerged which created a triple burden for participants. They endured socio-economic hardship encompassing limited economic and emotional support. Participants battled the consequences of life-threatening MDR-TB including illness, hospitalisation, stigma, and other challenges. Finally, participants were left with life-changing hearing loss. Conclusion: The findings indicate the necessity of holistic management of adolescents with aminoglycoside-related acquired hearing loss and serves as motivation to improve ototoxic monitoring practices and patient uptake of monitoring services and calls for the cessation, or at least cautious use, of aminoglycosides.

Clinical Considerations for Routine Auditory and Vestibular Monitoring in Patients With Cystic Fibrosis.

Purpose Specific classes of antibiotics, such as aminoglycosides, have well-established adverse events producing permanent hearing loss, tinnitus, and balance and/or vestibular problems (i.e., ototoxicity). Although these antibiotics are frequently used to treat pseudomonas and other bacterial infections in patients with cystic fibrosis (CF), there are no formalized recommendations describing approaches to implementation of guideline adherent ototoxicity monitoring as part of CF clinical care. Method This consensus statement was developed by the International Ototoxicity Management Working Group (IOMG) Ad Hoc Committee on Aminoglycoside Antibiotics to address the clinical need for ototoxicity management in CF patients treated with known ototoxic medications. These clinical protocol considerations were created using consensus opinion from a community of international experts and available evidence specific to patients with CF, as well as published national and international guidelines on ototoxicity monitoring. Results The IOMG advocates four clinical recommendations for implementing routine and guideline adherent ototoxicity management in patients with CF. These are (a) including questions about hearing, tinnitus, and balance/vestibular problems as part of the routine CF case history for all patients; (b) utilizing timely point-of-care measures; (c) establishing a baseline and conducting posttreatment evaluations for each course of intravenous ototoxic drug treatment; and (d) repeating annual hearing and vestibular evaluations for all patients with a history of ototoxic antibiotic exposure. Conclusion Increased efforts for implementation of an ototoxicity management program in the CF care team model will improve identification of ototoxicity signs and symptoms, allow for timely therapeutic follow-up, and provide the clinician and patient an opportunity to make an informed decision about potential treatment modifications to minimize adverse events. Supplemental Material https://doi.org/10.23641/asha.16624366.

Pharmacokinetics and other risk factors for kanamycin-induced hearing loss in patients with multi-drug resistant tuberculosis.

Objective: The toxicity associated with the use of kanamycin includes irreversible hearing loss. There are limited data describing the relationship between hearing loss and kanamycin pharmacokinetics (PK). We explored the association of kanamycin PK with hearing loss in patients on MDR-TB treatment.Design: We prospectively recruited patients on kanamycin-based MDR-TB treatment in Cape Town. Hearing thresholds from 0.25 to 16 kHz were tested at baseline and at 4, 8 and 12 weeks. We determined kanamycin concentrations at steady-state in serial plasma samples over 10 h, and explored factors associated with hearing loss.Study sample: One hundred and two participants including 58 (56.9%) men had analysable audiometric data; median age was 34.9 years, 65 (63.7%) were HIV-positive, and 24 (23.5%) had been treated for MDR-TB previously.Results: Eighty-four participants (82.4%) developed hearing loss. We found a 3% (95% CI: 1-6%, p = 0.028) increased risk of cochleotoxicity for each 10 µg h/L increase in 0-10 h AUC.Conclusion: We describe a high incidence of hearing loss in MDR-TB patients treated with kanamycin, with higher AUC0-10 significantly associated with hearing loss.

Towards the preferred stimulus parameters for distortion product otoacoustic emissions in adults: A preliminary study.

BACKGROUND:  Although distortion product otoacoustic emissions (DPOAEs) are useful in evaluating cochlear outer hair cell function, determining the optimal stimulus parameters could result in a more reliable, sensitive and specific diagnostic tool across the range of DPOAE applications. Objectives: To identify which stimulus parameters warrant further investigation for eliciting the largest and most reliable DPOAEs in adult humans. Method: A single group, repeated measures design involving a convenience sample of 20 normal-hearing participants between 19 and 24 years of age. Results: Descriptive statistics and mixed model analyses suggested L1/L2 intensity levels of 65/65 dB sound pressure level (SPL) and 65/55 dB SPL, and f2/f1 ratios of 1.18, 1.20 and 1.22 elicited larger and more reliable DPOAEs in both ears. Conclusion: Further investigation of the 65/65 dB SPL and 65/55 dB SPL intensity levels and the 1.18, 1.20 and 1.22 f2/f1 ratios is warranted to determine the stimulus parameters for eliciting the largest and most reliable DPOAEs in adult humans across the range of DPOAE applications.

A systematic review of stimulus parameters for eliciting distortion product otoacoustic emissions from adult humans.

OBJECTIVE: The objective of this study is to review the scientific literature to determine if a set of stimulus parameters can be described to elicit distortion product otoacoustic emissions (DPOAEs) of higher absolute level and/or greater reliability in healthy adult humans and higher sensitivity and specificity in adults with cochlear lesions. DESIGN: Systematic review. STUDY SAMPLE: Searches of four electronic databases yielded 47 studies that had used different parameters to elicit DPOAEs from within or between-groups of adult humans. RESULTS: The wide range of stimulus parameters used in the reviewed studies saw a wide range of reported values for DPOAE level, reliability, and sensitivity and specificity to cochlear lesions. CONCLUSION: The most commonly used stimulus parameters for eliciting DPOAEs from adult humans have included frequency ratios for the two primary tones (f2/f1) of between 1.04 and 1.4 and levels (L1/L2) of 65/55 dB SPL. The most commonly used parameters for eliciting DPOAEs of higher level in healthy adults appear to be linked to f2/f1 values between 1.20 and 1.22 and L1/L2 levels of 75/75 dB SPL. The stimulus parameters for eliciting DPOAEs of greater reliability in healthy adults and higher sensitivity and specificity in adults with cochlear lesions have yet to be clearly determined.

The occurrence of auditory dysfunction in children with TB receiving ototoxic medication at a TB hospital in South Africa.

OBJECTIVES: to describe the auditory dysfunction of children with tuberculosis receiving ototoxic medication at a residential TB hospital in the Cape Town metropolitan area. METHODS: A descriptive survey research design was adopted. The auditory status of participants was evaluated by otoscopy, immittance, audiometry or OAE and AABR (depending on the age). STUDY SAMPLE: 29 in-patients (7 months to 16.6 years). RESULTS: Fifty five percent of participants presented with middle ear abnormalities (n=16) and 48% (n=12) had sensorineural or mixed hearing loss. The degree of hearing loss ranged from mild to profound in 16% of the ears. The conventional pure-tone average of .5, 1, & 2 kHz did not allow for the determination of the degree of hearing loss in the remaining 18% which had high frequency hearing loss. CONCLUSIONS: The high occurrence of hearing loss necessitates the implementation of monitoring program for children receiving ototoxic medication. Consideration should be given to using the average of hearing thresholds at 4, 6 and 8 kHz to determine the classification of degree of hearing loss in cases of ototoxicity.

Identifying a context-effective school hearing screening test: An emic/etic framework.

OBJECTIVE: To identify a context-effective hearing screening test for primary schools in the Western Cape, South Africa using an emic-etic framework for test selection. DESIGN: A sequential mixed methods design was used to: (1) Identify test properties needed to successfully screen hearing in primary school children in the Western Cape, (2) select the hearing screening test most likely to succeed in this context, and (3) assess the use of the test in context. STUDY SAMPLE: Three nurses, two nursing assistants, two paediatric audiologists, and 100 grade-one children participated. RESULTS: Distortion product otoacoustic emissions (DPOAEs) were identified as the test most likely to succeed as a hearing screening test in primary school children in the Western Cape. While school nurses were able to successfully apply OAE testing in this context, its sensitivity to hearing loss in these children was 57.14%. CONCLUSIONS: The sensitivity would need to be improved before OAE testing could be used as a context-effective screening test for primary school children in the Western Cape. The study demonstrated the value of collaborative program planning using an emic-etic framework to ensure that screening tests are contextually appropriate.

Aminoglycoside-induced hearing loss in HIV-positive and HIV-negative multidrug-resistant tuberculosis patients.

Background. Ototoxicity following aminoglycoside treatment for multidrug-resistant tuberculosis (MDR-TB) is a significant problem. This study documents the incidence of ototoxicity in HIV-positive and HIV-negative patients with MDR-TB and presents clinical guidelines relating to ototoxicity. Methods. A prospective cohort study of 153 MDR-TB patients with normal hearing and middle ear status at baseline controlling for 6 mitochondrial mutations associated with aminoglycoside-related ototoxicity, at Brooklyn Chest Hospital in Cape Town. Pure tone audiometry was performed monthly for 3 months to determine hearing loss. HIV status was recorded, as was the presence of 6 mutations in the MT-RNR1 gene. Results. Fifty-seven per cent developed high-frequency hearing loss. HIV-positive patients (70%) were more likely to develop hearing loss than HIV-negative patients (42%). Of 115 patients who were genetically screened, none had MT-RNR1 mutations. Conclusion. Ototoxic hearing loss is common in MDR-TB patients treated with aminoglycosides. HIV-positive patients are at increased risk of ototoxicity. Auditory monitoring and auditory rehabilitation should be an integral part of the package of care of MDR-TB patients.

Vuvuzelas at South African soccer matches: risks for spectators' hearing.

South African Premier Soccer League (PSL) matches are known worldwide as some of the noisiest recreational events. Therefore, the objectives of this study were to i) measure noise levels during different PSL matches; ii) measure changes in auditory function after attending PSL matches; and iii) determine the factors that increase the risk of overexposure to noise during PSL matches. The study used a descriptive quantitative analytical pre- and post-exposure design. Participants (n = 19, and n = 10) attended two PSL matches. Each participant's auditory function was assessed using distortion product oto-acoustic emissions (DPOAEs) before and after attending a PSL match. Peak and equivalent continuous noise levels as well as noise dose were measured during each match. Noise levels recorded during the poorly attended Match 1 were lesser than those of the well-attended Match 2. Participants attending Match 2 had statistically significant reduction in their DPOAE amplitudes after the match (P = 0.003) than those attending Match 1. Vuvuzela blowers and participants seated within 1 m from them were most at risk of harm to their hearing with significant reduction in DPOAE amplitudes post the match (P = 0.002 and P = 0.008, respectively). It was therefore concluded that noise levels at well-attended South African PSL matches pose a significant risk to spectators' auditory function as shown by reduced DPOAE amplitude post match attendance. Three risk factors for overexposure to noise during the match were identified: blowing the vuvuzela, close proximity to the individual blowing the vuvuzela as well as spectator turnout at the match.