Surveillance for ototoxicity in platinum-based chemotherapy using mobile health audiometry with extended high frequencies.

OBJECTIVE: This study investigated mobile health enabled surveillance in ototoxicity. METHOD: This was a longitudinal study of 32 participants receiving chemotherapy. Baseline and exit audiograms that included conventional and extended high frequency audiometry were recorded within the patient's treatment venue using a validated mobile health audiometer. RESULTS: Average hearing thresholds at baseline were within the normal range (81.2 per cent left; 93.8 per cent right), reducing at exit testing (71.9 per cent left; 78.1 per cent right). Half of participants presented with a threshold shift according to ototoxicity monitoring criteria. The frequencies affected the most were between 4000 and 16 000 Hz, with left ears significantly more affected than right ears. Noise levels exceeded the maximum permissible ambient noise levels in up to 43.8 per cent of low frequencies (250-1000 Hz). CONCLUSION: Mobile health supported audiometry proved to be an efficacious tool for ototoxicity monitoring at the treatment venue. Changes in hearing ability over time could be tracked, improving surveillance in patients with full treatment schedules.

Hearing healthcare in remote or resource-constrained environments.

BACKGROUND: Hearing loss is a leading contributor to the global burden of disease, with more than 80 per cent of affected persons residing in low- and middle-income countries, typically where hearing health services are unavailable. OBJECTIVES: This article discusses the challenges to hearing care in remote and resource-limited settings, and describes recommended service delivery models, taking personnel and equipment requirements into consideration. The paper also considers the novel roles of telemedicine approaches in these contexts for improving access to preventative care. Finally, two case studies illustrate the challenges and strategies for service provision in remote and underserved settings.

Does otitis media in early childhood affect later behavioural development? Results from the Western Australian Pregnancy Cohort (Raine) Study.

OBJECTIVES: To examine the relationship between early life episodes of otitis media and later behavioural development with adjustment for confounders. DESIGN: Longitudinal cohort study. SETTING: The Western Australian Pregnancy Cohort (Raine) Study recruited 2900 pregnant women from King Edward Memorial Hospital (KEMH) in Perth, Western Australia, between 1989 and 1991. PARTICIPANTS: Data from the children born were collected at both the Year 3 and Year 5 follow-up. At Year 3, n = 611 were diagnosed with recurrent otitis media through parent-report and clinical examination. At Year 5, n = 299 were considered exposed to otitis media based upon tympanometry results. MAIN OUTCOME MEASURES: Performance in the Child Behaviour Checklist (CBCL), a questionnaire completed by the primary caregiver at Year 10. RESULTS: Significant associations were found between recurrent otitis media at Year 3 and internalising behaviours (P = .011), and the somatic (P = .011), withdrawn (P = .014), attention (P = .003) and thought problems domains (P = .021), and the total CBCL score (P = .010). A significant association was also found between exposure to otitis media at Year 5 and externalising behaviours (P = .026). CONCLUSIONS: A modest association was seen between recurrent otitis media at Year 3 and exposure to otitis media at Year 5 and a number of behaviour domains at Year 10.

Associations between cardiovascular disease and its risk factors with hearing loss-A cross-sectional analysis.

OBJECTIVES: To investigate the relationship between hearing loss and cardiovascular disease risk factors. DESIGN: Cross-sectional study. METHODS: Participants were recruited between May 2010 and December 2015 and answered a health and risk factor questionnaire. Physical and biochemical assessments were performed. SETTING: A community-based population. PARTICIPANTS: A total of 5107 participants born within the years 1946-1964 enrolled in the Busselton Healthy Ageing Study. MAIN OUTCOME MEASURES: Hearing was assessed behaviourally through the best ear pure-tone average (500, 1000, 2000, 4000 Hz), low-frequency average (250, 500, 1000 Hz) and high-frequency average (4000, 8000 Hz). Self-reported hearing loss, tinnitus and hyperacusis were assessed via questionnaire. Cardiovascular risk factors were assessed via a patient-completed questionnaire and objective measurements including blood pressure, body mass index, waist circumference, lipid profile and glycated haemoglobin. RESULTS: Of the participants, 54% were female, with the mean age of 58 years (range 45-69 years). Age, sex and family history of hearing loss were consistently strong determinants of hearing loss outcomes. After adjusting for these, obesity, current smoking, peripheral arterial disease and history of cardiovascular disease were significantly associated with pure-tone, low-frequency and high-frequency hearing loss. In addition, high blood pressure, triglyceride and glycated haemoglobin were significantly associated with low-frequency hearing loss. There was a graded association between hearing loss and Framingham Risk Score for cardiovascular risk (P<0.001). CONCLUSIONS: Established cardiovascular disease and individual and combined cardiovascular disease risk factors were found to be associated with hearing loss. Future research should prospectively investigate whether targeting cardiovascular disease can prevent hearing loss.

Protective benefit of predominant breastfeeding against otitis media may be limited to early childhood: results from a prospective birth cohort study.

OBJECTIVES: To examine the long-term effects of predominant breastfeeding on incidence of otitis media. DESIGN: Prospective birth cohort study. SETTING: The West Australian Pregnancy Cohort (Raine) Study recruited 2900 mothers through antenatal clinics at the major tertiary obstetric hospital in Perth, Western Australia, between 1989 and 1992. PARTICIPANTS: In total, 2237 children participated in a 6-year cohort follow-up, and a subset of 1344 were given ear and hearing assessments. MAIN OUTCOME MEASURES: OM diagnosis at 6 years of age (diagnosed by low-compliance tympanograms, 0-0.1 mmho). This was compared to OM diagnosed at the 3-year cohort follow-up using parent-report measures. Main exposure measures were duration of predominant breastfeeding (defined as the age other milk was introduced) and duration of partial (any) breastfeeding (defined as the age breastfeeding was stopped). RESULTS: There was a significant, independent association between predominant breastfeeding (OR = 1.33 [1.04, 1.69]; P = 0.02) and OM, and breastfeeding duration (OR = 1.35 [1.08, 1.68]; P = 0.01) with OM at 3 years of age. However, at 6 years of age, this relationship was no longer statistically significant (predominant breastfeeding OR = 0.78 [0.48, 1.06]; P = 0.09; duration of breastfeeding, OR = 1.34 [0.81, 2.23]; P = 0.25). CONCLUSIONS: Our findings are in line with a number of epidemiological studies which show a positive association between breastfeeding and OM in early childhood. However, the long-term follow-up of these children revealed that by 6 years of age, there was no significant influence of breastfeeding on presence of OM. These results suggest that the protective effect of predominant breastfeeding for at least 6 months does not extend to school-age children, where other social and environmental factors may be stronger predictors of OM.

Paediatric otitis media at a primary healthcare clinic in South Africa.

BACKGROUND: No published studies on the prevalence of paediatric otitis media at primary healthcare clinics (PHCs) in South Africa (SA) are available. OBJECTIVE: To examine the point prevalence of otitis media in a paediatric population in a PHC in Johannesburg, SA, using otomicroscopy. METHODS: A sample of 140 children aged 2 - 16 years (mean 6.4; 44.1% females) were recruited from patients attending the PHC. Otomicroscopy was completed for each of the participants' ears by a specialist otologist using a surgical microscope. RESULTS: Cerumen removal was necessary in 36.0% of participants (23.5% of ears). Otitis media with effusion was the most frequent diagnosis (16.5%). Chronic suppurative otitis media (CSOM) was diagnosed in 6.6% of children and was the most common type of otitis media in participants aged 6 - 15 years. Acute otitis media was only diagnosed in the younger 2 - 5-year age group (1.7%). Otitis media was significantly more prevalent among younger (31.4%) than older children (16.7%). CONCLUSION: CSOM prevalence, as classified by the World Health Organization, was high. Consequently diagnosis, treatment and subsequent referral protocols may need to be reviewed to prevent CSOM complications.

Does the human immunodeficiency virus influence the vestibulocollic reflex pathways? A comparative study.

BACKGROUND: This study compared vestibulocollic reflex and vestibulo-ocular reflex functioning in subjects with and without human immunodeficiency virus. It also described test results throughout progression of the disease and compared the results of human immunodeficiency virus positive subjects who were receiving antiretroviral therapies with those not receiving this treatment. METHODS: Subjects comprised 53 adults with human immunodeficiency virus (mean age 38.5 ± 4.4 years) and 38 without human immunodeficiency virus (mean age 36.9 ± 8.2 years). Clinical examinations included cervical vestibular-evoked myogenic potential and bithermal caloric testing. RESULTS: Abnormal cervical vestibular-evoked myogenic potential and caloric results were significantly higher in the human immunodeficiency virus positive group (p = 0.001), with an odds ratio of 10.2. Vestibulocollic reflex and vestibulo-ocular reflex involvement increased with progression of the disease. There were more abnormal test results in subjects receiving antiretroviral therapies (66.7 per cent) than in those not receiving antiretroviral therapies (63.6 per cent), but this difference was insignificant. CONCLUSION: Human immunodeficiency virus seems to influence vestibulocollic reflex pathways. Combining cervical vestibular-evoked myogenic potential and caloric testing may be useful to detect early neurological involvement in human immunodeficiency virus positive subjects.

An auditory profile of sclerosteosis.

Objective: To characterise auditory involvement secondary to excessive craniotubular bone growth in individuals with sclerosteosis in South Africa. Methods: This cross-sectional study assessed the auditory profile of 10 participants with sclerosteosis. An auditory test battery was used and results for each ear were recorded using descriptive and comparative analyses. Results: All participants presented with bilateral, mixed hearing losses. Of the 20 ears, hearing loss was moderate in 5 per cent (n = 1), severe in 55 per cent (n = 11) and profound in 40 per cent (n = 8). Air-bone gaps were smaller in older participants, although the difference was not statistically significant (p > 0.05). Computed tomography scans indicated pervasive abnormalities of the external auditory canal, tympanic membrane, middle-ear space, ossicles, oval window, round window and internal auditory canal. Narrowed internal auditory canals corresponded to poor speech discrimination, indicative of retrocochlear pathology and absent auditory brainstem response waves. Conclusion: Progressive abnormal bone formation in sclerosteosis involves the middle ear, the round and oval windows of the cochlea, and the internal auditory canal. The condition compromises conductive, sensory and neural auditory pathways, which results in moderate to profound, mixed hearing loss.

Noise and age-related hearing loss: a study of 40 123 gold miners in South Africa.

OBJECTIVE AND DESIGN: This retrospective cohort study aimed to describe the differential effect of noise exposure and age-related hearing loss in a large sample of gold miners in South Africa. STUDY SAMPLE: Audiological data of 40 123 South African mine workers were investigated. Data of a non-noise-exposed control group (n = 6162) and group exposed to underground noise (≥ 85 dB A (TWA) (n = 33 961) were included. Within these two larger noise-exposed groups two homogenous exposure groups (HEG) were also selected for analyses, namely the driller group (n = 4399) and the administration group (administrative workers) (n = 2211). Participants were categorized in terms of noise exposure, age, and race. RESULTS: Significantly different thresholds (worse for underground noise group) with respect to the median for all frequencies after adjusting for age was evident between the noise-exposed and control groups (ANCOVA). The largest differences in hearing thresholds between the noise-exposed and control groups were observed at 3 and 4 kHz in the age group 36 to 45 years. Administration and driller group differed significantly (driller group worse results) with respect to the mean LFA512 and HFA346 after adjusting for age (ANCOVA). Black males had significantly better high-frequency hearing compared with white male counterparts but significantly worse low-frequency hearing. CONCLUSION: Age was the most important influence on hearing thresholds for the noise and control groups. Race was shown to be a very significant factor determining susceptibility to NIHL and ARHL.

Seasonal changes in burrow geometry of the common mole rat (Rodentia: Bathyergidae).

Sociality in mole rats has been suggested to have evolved as a response to the widely dispersed food resources and the limited burrowing opportunities that result from sporadic rainfall events. In the most arid regions, individual foraging efficiency is reduced, and energetic constraints increase. In this study, we investigate seasonal differences in burrow architecture of the social Cryptomys hottentotus hottentotus in a mesic region. We describe burrow geometry in response to seasonal weather conditions for two seasons (wet and dry). Interactions occurred between seasons and colony size for the size of the burrow systems, but not the shape of the burrow systems. The fractal dimension values of the burrow systems did not differ between seasons. Thus, the burrow complexity was dependent upon the number of mole rats present in the social group.

Systematic review of vestibular disorders related to human immunodeficiency virus and acquired immunodeficiency syndrome.

INTRODUCTION: Disorders of the auditory and vestibular system are often associated with human immunodeficiency virus infection and acquired immunodeficiency syndrome. However, the extent and nature of these vestibular manifestations are unclear. OBJECTIVE: To systematically review the current peer-reviewed literature on vestibular manifestations and pathology related to human immunodeficiency virus and acquired immunodeficiency syndrome. METHOD: Systematic review of peer-reviewed articles related to vestibular findings in individuals with human immunodeficiency virus infection and acquired immunodeficiency syndrome. Several electronic databases were searched. RESULTS: We identified 442 records, reduced to 210 after excluding duplicates and reviews. These were reviewed for relevance to the scope of the study. DISCUSSION: We identified only 13 reports investigating vestibular functioning and pathology in individuals affected by human immunodeficiency virus and acquired immunodeficiency syndrome. This condition can affect both the peripheral and central vestibular system, irrespective of age and viral disease stage. Peripheral vestibular involvement may affect up to 50 per cent of patients, and central vestibular involvement may be even more prevalent. Post-mortem studies suggest direct involvement of the entire vestibular system, while opportunistic infections such as oto- and neurosyphilis and encephalitis cause secondary vestibular dysfunction resulting in vertigo, dizziness and imbalance. CONCLUSION: Patients with human immunodeficiency virus and acquired immunodeficiency syndrome should routinely be monitored for vestibular involvement, to minimise functional limitations of quality of life.

Effect of prolonged contralateral acoustic stimulation on transient evoked otoacoustic emissions.

Although the suppressive effect of the medial olivocochlear system (MOCS) on peripheral auditory active mechanisms is well documented in humans, the effect of efferent inhibition over prolonged periods of acoustic stimulation is less well documented, especially as observed by transient evoked otoacoustic emission (TEOAE) suppression. The present study evaluated the relationship between the duration of contralateral acoustic stimulation and the suppression of TEOAE in 10 normal-hearing adults. TEOAE recordings with linear clicks (60 dB SPL) were measured at four intervals during 15 min of continuous contralateral white noise (45 dB SL), followed by two post-noise recordings. An identical within-subject control condition was recorded without contralateral noise. Experimental and control measurements were repeated three times, on separate days. Results revealed significant and sustained TEOAE amplitude reduction for the entire duration of contralateral stimulation. Suppression increased gradually for the duration of contralateral noise presented, but not sufficiently to be statistically significant. Three minutes after noise termination, TEOAE amplitudes increased to values significantly above control recordings. The MOCS is able to sustain suppression over a prolonged duration of contralateral stimulation, supporting its role as an active modulator of outer hair cell mechanics during ongoing stimuli.

Auditory pathology in cri-du-chat (5p-) syndrome: phenotypic evidence for auditory neuropathy.

5p-(cri-du-chat syndrome) is a well-defined clinical entity presenting with phenotypic and cytogenetic variability. Despite recognition that abnormalities in audition are common, limited reports on auditory functioning in affected individuals are available. The current study presents a case illustrating the auditory functioning in a 22-month-old patient diagnosed with 5p- syndrome, karyotype 46,XX,del(5)(p13). Auditory neuropathy was diagnosed based on abnormal auditory evoked potentials with neural components suggesting severe to profound hearing loss in the presence of cochlear microphonic responses and behavioral reactions to sound at mild to moderate hearing levels. The current case and a review of available reports indicate that auditory neuropathy or neural dys-synchrony may be another phenotype of the condition possibly related to abnormal expression of the protein beta-catenin mapped to 5p. Implications are for routine and diagnostic specific assessments of auditory functioning and for employment of non-verbal communication methods in early intervention.

Newborn hearing screening in a South African private health care hospital.

OBJECTIVE: Early Hearing Detection and Intervention (EHDI) programs are being established as part of the public health systems in increasing numbers of countries. In developing countries, however, little progress has been made towards implementing NHS programs and South Africa's public and private health care sectors is no exception. The current study presents the first report on a hospital-based UNHS program conducted in the South African private health care sector to provide preliminary results towards advocating for and guiding future programs. METHODS: A retrospective study of a UNHS program at a private hospital in urban Gauteng, South Africa over a 4 year period of time was performed. Screening was conducted with Transient Evoked Otoacoustic Emissions (TEOAE) with a rescreen recommended within 6 weeks if referred. Diagnostic audiological assessments were performed on those infants referring the rescreen. The discharge screening costs were subsidized through the hospital birthing package for the first 22 months of the program. RESULTS: Six thousand two hundred and forty-one newborns were screened from 13,799 hospital births during the first 4 years. Ninety-four percent of these infants were from the well-baby nurseries. During the initial 22 months, whilst the service was subsidized as part of the hospital birthing package, coverage of 75% was attained compared to 20% during the subsequent 26 months. The overall referral rate for the screening program across the 4 years was 11.1% but referral rates decreased by between 2 and 4% for each year of program existence with a 5% rate in year 4. Only 32% of the rescreens were completed at the hospital and no data was available for the remaining infants because parents were provided a choice of follow up centers. Referral for a diagnostic assessment after the rescreens at the hospital was predictive of sensorineural hearing loss in one-third of cases and the estimated prevalence was 3 in every 1000. CONCLUSIONS: Screening coverage in the current study was not adequately high and can be attributed to insufficient parental knowledge to make an informed decision. Improvements in program efficiency over time also suggest that pilot programs must be monitored over sufficiently long periods of time to allow observations of optimal efficiency. Initial referral rates and prevalence data indicate a large hearing loss burden and the capacity to implement increasingly efficient programs in South Africa.

Selected chemical parameters in the blood and metals in the organs of the Nile crocodile, Crocodylus Niloticus, in the Kruger National Park.

Healthy and sick crocodiles of varying sizes were examined from the Olifants River in the central part of the Kruger National Park, the Sabi River in the southern part and the Shingwedzi River in the northern region. Blood was collected for the determination of certain parameters and samples of fat, muscle, kidney and liver tissue were collected and analyzed for their heavy metal content. The results of the blood analyses are within the range recorded in the literature, but the metal analyses were inconclusive as similar data are not available for comparison. The results of the metal analyses are presented here for use as baseline and reference data.

Leiperia cincinnalis Sambon, 1922 (Pentastomida) from Nile crocodiles Crocodylus niloticus in the Kruger National Park, South Africa, with a description of the male.

A single male and several adult females of the pentastomid Leiperia cincinnalis were recovered from the trachea of five of six Nile crocodiles examined in 1995 and 1998. Infective larvae, pre-adult males and females, as well as mature males, occurred in clusters in the pulmonary artery but infective larvae and pre-adult females were also occasionally taken from the lungs. Irrespective of the developmental stage, the intensity of infection was 3, 6, 48, 72 and 79. Sixty-four percent of eggs recovered from the posterior part of the uterus of a patent L. cincinnalis female contained fully-developed primary larvae and these were used to infect 24 Mozambique bream Oreochromis mossambicus. Within a week of infection all the fish died and hatched primary larvae were recovered from the stomach and anterior part of the intestine. Eggs that had not hatched were found to be unsegmented. The total primary larval count in seven fish was 18, 12, 1, 25, 16, >40 and >50. Descriptions with detailed measurements are given of the females, the males, the eggs, the primary larvae and the infective larvae of L. cincinnalis.