Absent otoacoustic emissions predict otitis media in young Aboriginal children: a birth cohort study in Aboriginal and non-Aboriginal children in an arid zone of Western Australia

Ear and hearing outcomes in Aboriginal infants living in an urban Australian area: the Djaalinj Waakinj birth cohort study

OBJECTIVE

Describe the ear and hearing outcomes in Aboriginal infants in an Australian urban area.

DESIGN

Aboriginal infants enrolled in the Djaalinj Waakinj prospective cohort study had ear health screenings at ages 2-4, 6-8 and 12-18 months and audiological assessment at ∼12 months of age. Sociodemographic, environmental characteristics, otoscopy, otoacoustic emissions, tympanometry and visual reinforcement audiometry data were collected.

STUDY SAMPLE

125 infants were enrolled in the study; 67 completed audiological assessment, 62, 54, and 58 of whom attended ear screenings at 2-4, 6-8 and 12-18 months.

RESULTS

Of the children that attended the audiological assessment, 36.5%, 50% and 64.3% of infants had otitis media (OM) at 2-4, 6-8 and 12-18 months. Using a 10 dB correction factor, 44.8% of infants had hearing loss (HL) (≥ 25 dB HL) at ∼ 12 months of age. More males (X2=5.4 (1df, p = 0.02)) and infants with OM at audiological assessment (X2=5.8 (1df, p = 0.02)) had HL. More infants that used a pacifier at 12-18 months of age had HL (X2=4.7 (1df, p = 0.03)).

CONCLUSION

Aboriginal infants in an urban area have high rates of HL and OM, which requires early surveillance and timely treatment to reduce the medical and developmental impacts of OM and HL.

Primary Health Care Interventions for Potentially Preventable Ear, Nose, and Throat Conditions in Rural and Remote Areas: A Systematic Review

Background:Primary and secondary level preventive primary health care programs providing early detection and timely management of ear, nose, and throat (ENT) conditions in rural and remote regions are fundamental to preventing downstream impacts on health, social, and educational outcomes. However, the range and quality of evidence is yet to be reviewed. Objectives: The study objectives were to identify and synthesize the evidence of primary health care interventions for detection and management of ENT conditions in rural and remote areas, and evaluate the quality of the research and effectiveness of interventions. Methods: A systematic literature search of 6 databases (February 2023). The review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement, and the quality appraisal of studies was evaluated using the Mixed Methods Appraisal Tool (initial screening questions: Are there clear research questions? Do the collected data allow to address the research questions?). Results: Ten studies met the inclusion criteria. The results describe interventions for detection and management of respiratory tract infections, otitis media, and ear disease in primary health care settings. No studies met the inclusion criteria for tonsillitis. The role of community-based programs and allied health workers in the detection and management of ENT conditions was found to be effective in rural and remote regions. Only 2 of the studies met the screening criteria for quality appraisal. Conclusions: The study findings may inform future programs and policy development to address detection and management of ENT conditions in rural and remote primary care settings, and supports the need for further research on innovative models of care targeting potentially preventable hospitalizations through primary and secondary level prevention.

An evaluation of the quality of ear health services for Aboriginal children living in remote Australia: a cascade of care analysis

BACKGROUND

In the Northern Territory (NT) the prevalence of otitis media (OM) in young Aboriginal children living in remote communities has persisted at around 90% over the last few decades. OM-associated hearing loss can cause developmental delay and adversely impact life course trajectories. This study examined the 5-year trends in OM prevalence and quality of ear health services in remote NT communities.

METHODS

A retrospective analysis was performed on de-identified clinical data for 50 remote clinics managed by the NT Government. We report a 6-monthly cascade analysis of the proportions of children 0-16 years of age receiving local guideline recommendations for surveillance, OM treatment and follow-up at selected milestones between 2014 and 2018.

RESULTS

Between 6,326 and 6,557 individual children were included in the 6-monthly analyses. On average, 57% (95%CI: 56-59%) of eligible children had received one or more ear examination in each 6-monthly period. Of those examined, 36% (95%CI: 33-40%) were diagnosed with some type of OM, of whom 90% had OM requiring either immediate treatment or scheduled follow-up according to local guidelines. Outcomes of treatment and follow-up were recorded in 24% and 23% of cases, respectively. Significant decreasing temporal trends were found in the proportion diagnosed with any OM across each age group. Overall, this proportion decreased by 40% over the five years (from 43 to 26%).

CONCLUSIONS

This cascade of care analysis found that ear health surveillance and compliance with otitis media guidelines for treatment and follow-up were both low. Further research is required to identify effective strategies that improve ear health services in remote settings.

Early onset of otitis media is a strong predictor of subsequent disease in urban Aboriginal infants: Djaalinj Waakinj cohort study

AIM

Australian Aboriginal and/or Torres Strait Islander children in rural/remote areas suffer high rates of persistent otitis media (OM) from early infancy. We aimed to determine the proportion of Aboriginal infants living in an urban area who have OM and investigate associated risk factors.

METHODS

Between 2017 and 2020, the Djaalinj Waakinj cohort study enrolled 125 Aboriginal infants at 0-12 weeks of age in the Perth South Metropolitan region, Western Australia. Proportion of children with OM based on tympanometry at ages 2, 6 and 12 months was evaluated, type B tympanogram indicating middle ear effusion. Potential risk factors were investigated by logistic regression with generalised estimating equations.

RESULTS

The proportion of children with OM was 35% (29/83) at 2 months, 49% (34/70) at 6 months and 49% (33/68) at 12 months of age. About 70% (16/23) of those with OM at ages 2 and/or 6 months had OM at 12 months compared with 20% (3/15) if no prior OM (relative risk = 3.48, 95% confidence interval (CI): 1.22-40.1). On multivariate analysis, infants living in houses with ≥1 person/room were at increased risk of OM (odds ratio = 1.78, 95% CI: 0.96-3.32).

CONCLUSION

Approximately half of Aboriginal infants enrolled into the South Metropolitan Perth project have OM by the age of 6 months and early onset of disease strongly predicts subsequent OM. Early surveillance for OM in urban areas is needed for early detection and management to reduce the risk of long-term hearing loss which can have serious developmental, social, behavioural, educational and economic consequences.

The role of Indigenous Health Workers in ear health screening programs for Indigenous children: a scoping review

OBJECTIVE

To identify and describe the involvement of Indigenous Health Workers within ear health screening programs for Indigenous Peoples in Australia, Canada, the US and New Zealand.

METHODS

Peer-reviewed and grey literature sources were systematically searched to identify evidence. This scoping review was conducted in accordance with the scoping review extension of the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines.

RESULTS

Forty pieces of evidence were included in this review. While almost all included studies identified the critical role of Indigenous Health Workers in ear and hearing health, Indigenous leadership and involvement in research projects and service delivery varied significantly and none of the included studies reported Indigenous health worker perspectives. Approximately half of the authorship teams had at least one Indigenous author.

CONCLUSIONS

There is a clear need for Indigenous leadership in ear and hearing health research and programming. Specialist teams involved in health service delivery and research need to enable this transition by understanding and privileging Indigenous leadership and investing in appropriate training for non-Indigenous specialists providing care in Indigenous health contexts.

IMPLICATIONS FOR PUBLIC HEALTH

These findings are discussed in terms of opportunities to improve Indigenous ear and hearing health research and programming.

BIGDATA: A Protocol to Create and Extend a 25-Year Clinical Trial and Observational Data Asset to Address Key Knowledge Gaps in Otitis Media and Hearing Loss in Australian Aboriginal and Non-Aboriginal Children

INTRODUCTION

Otitis media (OM) is a common childhood illness, often resolving without intervention and acute and long-term complications are rare. However, Australian Aboriginal and Torres Strait Islander infants and children experience a high burden of OM and are at high risk of complications (tympanic membrane perforation and chronic infections). Bacterial OM is commonly associated with Streptococcus pneumoniae, non-typeable Haemophilus influenzae, and Moraxella catarrhalis. BIGDATA is a data asset combining over 25 years of microbiology and OM surveillance research from the Ear Health Research Program at Menzies School of Health Research (Northern Territory, Australia), including 11 randomized controlled trials, four cohort studies, eight surveys in over 30 remote communities (including data from Western Australia), and five surveys of urban childcare centers including Aboriginal and Torres Strait Islander and non-Indigenous children. Outcome measures include clinical examinations (focusing on OM), antibiotic prescriptions, pneumococcal vaccination, modifiable risk factors such as smoking and household crowding, and nasopharyngeal and ear discharge microbiology including antimicrobial resistance testing.

METHODS AND ANALYSIS

The initial series of projects are planned to address the following key knowledge gaps: (i) otitis media prevalence and severity over pre pneumococcal conjugate vaccines (PCVs) and three eras of increasing PCV valency; (ii) impact of increasing valency PCVs on nasopharyngeal carriage dynamics of pneumococcal serotypes, and antimicrobial resistance; (iii) impact of increasing valency PCVs on nasopharyngeal carriage dynamics and antimicrobial resistance of other otopathogens; and (iv) serotype specific differences between children with acute OM and OM with effusion or without OM. These data will be utilized to identify research gaps, providing evidence-based prioritization for ongoing research.

ETHICS AND DISSEMINATION

Data asset creation and priority analyses were approved by the Human Research Ethics Committee of Northern Territory Department of Health and Menzies School of Health Research (EC00153, 18-3281), the Child and Adolescent Health Service Human Research Ethics Committee and Western Australian Aboriginal Health Ethics Committee. Dissemination will be through peer review publication and conference presentations.

A community-based service enhancement model of training and employing Ear Health Facilitators to address the crisis in ear and hearing health of Aboriginal children in the Northern Territory, the Hearing for Learning Initiative (the HfLI): study protocol for a stepped-wedge cluster randomised trial

Background

Almost all Aboriginal children in remote communities have persistent bilateral otitis media affecting hearing and learning throughout early childhood and school years, with consequences for social and educational outcomes, and later employment opportunities. Current primary health care and specialist services do not have the resources to meet the complex needs of these children.

Method/design

This stepped-wedge cluster randomised trial will allocate 18 communities to one of five 6-monthly intervention start dates. Stratification will be by region and population size. The intervention (Hearing for Learning Initiative, HfLI) consists of six 20-h weeks of training (delivered over 3 months) that includes Certificate II in Aboriginal Primary Health Care (3 modules) and competencies in ear and hearing data collection (otoscopy, tympanometry and hearScreen), plus 3 weeks of assisted integration into the health service, then part-time employment as Ear Health Facilitators to the end of the trial. Unblinding will occur 6 months prior to each allocated start date, to allow Community Reference Groups to be involved in co-design of the HfLI implementation in their community. Relevant health service data will be extracted 6-monthly from all 18 communities. The primary outcome is the difference in proportion of children (0 to 16 years of age) who have at least one ear assessment (diagnosis) documented in their medical record within each 6-month period, compared to control periods (no HfLI). Secondary outcomes include data on sustainability, adherence to evidence-based clinical guidelines for otitis media, including follow-up and specialist referrals, and school attendance. Structured interviews with staff working in health and education services, Ear Health Trainees, Ear Health Facilitators and families will assess process outcomes and the HfLI broader impact.

Discussion

The impact of training and employment of Ear Health Facilitators on service enhancement will inform the health, education and employment sectors about effectiveness of skills and job creation that empowers community members to contribute to addressing issues of local importance, in this instance ear and hearing health of children.

Trial registration

ClinicalTrials.gov NCT03916029. Registered on 16 April 2019.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05215-7.

Otitis media outcomes of a combined 10-valent pneumococcal Haemophilus influenzae protein D conjugate vaccine and 13-valent pneumococcal conjugate vaccine schedule at 1-2-4-6 months: PREVIX_COMBO, a 3-arm randomised controlled trial

BACKGROUND

Aboriginal children living in Australian remote communities are at high risk of early and persistent otitis media, hearing loss, and social disadvantage. Streptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi) are the primary pathogens. We compared otitis media outcomes in infants randomised to either a combination of Synflorix™ (PHiD-CV10, with protein D of NTHi) and Prevenar13™ (PCV13, with 3, 6A, and 19A), with recommended schedules for each vaccine alone. We previously reported superior broader overall immunogenicity of the combination schedule at 7 months, and early superiority of PHiD-CV10 compared to PCV13 at 4 months.

METHODS

In an open-label superiority trial, we randomised (1:1:1) Aboriginal infants at 28 to 38 days of age, to either Prevenar13™ (P) at 2-4-6 months (_PPP), Synflorix™ (S) at 2-4-6 months (_SSS), or Synflorix™ at 1-2-4 months plus Prevenar13™ at 6 months (SSSP). Ears were assessed using tympanometry at 1 and 2 months, combined with otoscopy at 4, 6, and 7 months. A worst ear diagnosis was made for each child visit according to a severity hierarchy of normal, otitis media with effusion (OME), acute otitis media without perforation (AOMwoP), AOM with perforation (AOMwiP), and chronic suppurative otitis media (CSOM).

RESULTS

Between September 2011 and September 2017, 425 infants were allocated to _PPP(143), _SSS(141) or SSSP(141). Ear assessments were successful in 96% scheduled visits. At 7 months prevalence of any OM was 91, 86, and 90% in the _PPP, _SSS, and SSSP groups, respectively. There were no significant differences in prevalence of any form of otitis media between vaccine groups at any age. Combined group prevalence of any OM was 43, 57, 82, 87, and 89% at 1, 2, 4, 6, and 7 months of age, respectively. Of 388 infants with ear assessments at 4, 6 and 7 months, 277 (71.4%) had OM that met criteria for specialist referral; rAOM, pOME, or CSOM.

CONCLUSIONS

Despite superior broader overall immunogenicity of the combination schedule at 7 months, and early superiority of PHiD-CV10 compared to PCV13 at 4 months, there were no significant differences in prevalence of otitis media nor healthy ears throughout the first months of life.

TRIAL REGISTRATION

ACTRN12610000544077 registered 06/07/2010 and ClinicalTrials.gov NCT01174849 registered 04/08/2010.

Hearing loss among Australian Aboriginal infants and toddlers: A systematic review

Aim

Australian Aboriginal and Torres Strait Islander children have among the highest rates of otitis media (OM) and associated conductive hearing loss in the world. OM begins early in life and is well-documented in the research literature. In contrast, audiology data for the infant and toddler age-groups are limited. This review aimed to summarise the recent literature on hearing loss among Aboriginal and Torres Strait Islander infants and toddlers.

Methods

Systematic literature review. PubMed and ScienceDirect databases were searched for relevant journal articles. Key search terms were “Aboriginal”, “children”, “hearing loss”, “otitis media”, and their relevant synonyms. Journal articles published before 2000 were excluded.

Results

Only two journal articles met review inclusion criteria. Ear disease and associated conductive hearing loss was significantly higher among Aboriginal and Torres Strait Islander than non-Aboriginal and Torres Strait Islander children. No intervention studies were found.

Conclusions

More research is needed to evaluate hearing health outcomes of medical (including surgical) and audiological interventions in this high-risk population.

Impact of hearing impairment on early childhood development in Australian Aboriginal children: A data linkage study

AIM

To investigate the association between hearing impairment (HI) and measures of early childhood development in Aboriginal children at age 5 years.

METHODS

An observational cohort study (n = 1037) of children aged 4.0-7.3 years (median 5.4 years), living in remote Northern Territory (NT) communities, was conducted using multiple linked administrative datasets, including the NT Perinatal Data Register, Remote Hearing Assessment records (2007-2015) and Australian Early Development Censuses (AEDC, 2009, 2012 and 2015). Outcome measures were summary and domain-specific AEDC results using both dichotomous and continuous variables (domain scores).

RESULTS

Compared with normal hearing children, after adjustment for selected confounding factors, those with moderate or worse HI had an adjusted odds ratio of 1.69 (95% confidence interval (CI), 1.03-2.77) for being developmentally vulnerable in two or more of the five AEDC domains. Children with mild HI and those with moderate to worse HI had lower domain score sum by -1.60 (95% CI, -3.02 to -0.18) and - 2.40 (95% CI, -4.50 to -0.30), respectively. There was also evidence for an association between HI and poorer outcomes in the 'language and cognitive skills', 'communication skills and general knowledge' and 'physical health and wellbeing' domains.

CONCLUSIONS

Otitis media-related HI is associated with increased risk for poorer outcomes in early childhood development and this risk appears to increase with higher levels of HI. Prevention and early treatment of otitis media will reduce both the disease and the associated negative impact on early child development, especially the development of language, cognitive and communication skills and physical health and wellbeing.

Moraxella catarrhalis phase-variable loci show differences in expression during conditions relevant to disease

Moraxella catarrhalis is a human-adapted, opportunistic bacterial pathogen of the respiratory mucosa. Although asymptomatic colonization of the nasopharynx is common, M. catarrhalis can ascend into the middle ear, where it is a prevalent causative agent of otitis media in children, or enter the lower respiratory tract, where it is associated with acute exacerbations of chronic obstructive pulmonary disease in adults. Phase variation is the high frequency, random, reversible switching of gene expression that allows bacteria to adapt to different host microenvironments and evade host defences, and is most commonly mediated by simple DNA sequence repeats. Bioinformatic analysis of five closed M. catarrhalis genomes identified 17 unique simple DNA sequence repeat tracts that were variable between strains, indicating the potential to mediate phase variable expression of the associated genes. Assays designed to assess simple sequence repeat variation under conditions mimicking host infection demonstrated that phase variation of uspA1 (ubiquitous surface protein A1) from high to low expression occurs over 72 hours of biofilm passage, while phase variation of uspA2 (ubiquitous surface protein A2) to high expression variants occurs during repeated exposure to human serum, as measured by mRNA levels. We also identify and confirm the variable expression of two novel phase variable genes encoding a Type III DNA methyltransferase (modO), and a conserved hypothetical permease (MC25239_RS00020). These data reveal the repertoire of phase variable genes mediated by simple sequence repeats in M. catarrhalis and demonstrate that modulation of expression under conditions mimicking human infection is attributed to changes in simple sequence repeat length.

The link between hearing impairment and child maltreatment among Aboriginal children in the Northern Territory of Australia: is there an opportunity for a public health approach in child protection?

Background

International studies provide evidence of an association between child disabilities, including hearing impairment (HI), and child maltreatment. There are high prevalences of ear disease with associated HI, and child maltreatment among Australian Aboriginal children, but the link between HI and child maltreatment is unknown. This study investigates the association between HI and child maltreatment for Aboriginal children living in the Northern Territory (NT) of Australia.

Methods

This was a retrospective cohort study of 3895 Aboriginal school-aged children (born between 1999 and 2008) living in remote NT communities. The study used linked individual-level information from health, education and child protection services. The outcome variables were child maltreatment notifications and substantiations. The key explanatory variable, HI, was based on audiometric assessment. The Kaplan–Meier estimator method was used in univariate analysis; Cox proportional hazards regression was used in multivariable analysis.

Results

A majority of the study cohort lived in very remote (94.5%) and most disadvantaged (93.1%) regions. Among all children in the study cohort, 56.1% had a record of either HI or unilateral hearing loss (UHL), and for those with a history of contact with child protection services (n = 2757), 56.7% had a record of HI/UHL (n = 1564). In the 1999–2003 birth cohort, by age 12 years, 53.5% of children with a record of moderate or worse HI had at least one maltreatment notification, compared to 47.3% of children with normal hearing. In the 2004–2008 cohort, the corresponding results were 83.4 and 71.7% respectively. In multivariable analysis, using the full cohort, children with moderate or worse HI had higher risk of any child maltreatment notification (adjusted Hazard Ratios (adjHR): 1.16, 95% CI:1.04–1.30), notification for neglect (adjHR:1.17, 95% CI:1.04–1.31) and substantiation (adjHR:1.20, 95% CI:1.04–1.40), than children with normal hearing. In the 2004–2008 birth cohort, children with moderate or worse HI had higher risk of a substantiated episode of physical abuse (adjHR:1.47, 95% CI:1.07–2.03) than children with normal hearing.

Conclusion

Our findings demonstrate the urgent need for HI and child maltreatment prevention strategies through raised community awareness and inter-agency collaboration. Effective information-sharing between service providers is a critical first step to a public health approach in child protection.

Hearing and justice: The link between hearing impairment in early childhood and youth offending in Aboriginal children living in remote communities of the Northern Territory, Australia

BACKGROUND

High prevalence of chronic middle ear disease has persisted in Australian Aboriginal children, and the related hearing impairment (HI) has been implicated in a range of social outcomes. This study investigated the association between HI in early childhood and youth offending.

METHOD

This was a retrospective cohort study of 1533 Aboriginal children (born between 1996 and 2001) living in remote Northern Territory communities. The study used linked individual-level information from health, education, child protection and youth justice services. The outcome variable was a youth being "found guilty of an offence". The key explanatory variable, hearing impairment, was based on audiometric assessment. Other variables were: child maltreatment notifications, Year 7 school enrolment by mother, Year 7 school attendance and community 'fixed- effects'. The Cox proportional hazards model was used to estimate the association between HI and youth offending; and the Royston R2 measure to estimate the separate contributions of risk factors to youth offending.

RESULTS

The proportion of hearing loss was high in children with records of offence (boys: 55.6%, girls: 36.7%) and those without (boys: 46.1%; girls: 49.0%). In univariate analysis, a higher risk of offending was found among boys with moderate or worse HI (HR: 1.77 [95% CI: 1.05-2.98]) and mild HI (HR: 1.54 [95% CI:1.06-2.23]). This association was attenuated in multivariable analysis (moderate HI, HR: 1.43 [95% CI:0.78-2.62]; mild HI, HR: 1.37 [95% CI: 0.83-2.26]). No evidence for an association was found in girls. HI contributed 3.2% and 6.5% of variation in offending among boys and girls respectively. Factors contributing greater variance included: community 'fixed-effects' (boys: 14.6%, girls: 36.5%), child maltreatment notification (boys: 14.2%, girls: 23.9%) and year 7 school attendance (boys: 7.9%; girls 12.1%). Enrolment by mother explained substantial variation for girls (25.4%) but not boys (0.2%).

CONCLUSION

There was evidence, in univariate analysis, for an association between HI and youth offending for boys however this association was not evident after controlling for other factors. Our findings highlight a range of risk factors that underpin the pathway to youth-offending, demonstrating the urgent need for interagency collaboration to meet the complex needs of vulnerable children in the Northern Territory.

Australian Aboriginal children have higher hospitalization rates for otitis media but lower surgical procedures than non-Aboriginal children: A record linkage population-based cohort study

Introduction

Otitis media (OM) is one of the most common infectious diseases affecting children globally and the most common reason for antibiotic prescription and paediatric surgery. Australian Aboriginal children have higher rates of OM than non-Aboriginal children; however, there are no data comparing OM hospitalization rates between them at the population level. We report temporal trends for OM hospitalizations and in-hospital tympanostomy tube insertion (TTI) in a cohort of 469,589 Western Australian children born between 1996 and 2012.

Materials and methods

We used the International Classification of Diseases codes version 10 to identify hospitalizations for OM or TTI recorded as a surgical procedure. Using age-specific population denominators, we calculated hospitalization rates per 1,000 child-years by age, year and level of socio-economic deprivation.

Results

There were 534,674 hospitalizations among 221,588 children hospitalized at least once before age 15 years. Aboriginal children had higher hospitalization rates for OM than non-Aboriginal children (23.3/1,000 [95% Confidence Interval (CI) 22.8,24.0] vs 2.4/1,000 [95% CI 2.3,2.4] child-years) with no change in disparity over time. Conversely non-Aboriginal children had higher rates of TTI than Aboriginal children (13.5 [95% CI 13.2,13.8] vs 10.1 [95% CI 8.9,11.4]). Children from lower socio-economic backgrounds had higher OM hospitalization rates than those from higher socio-economic backgrounds, although for Aboriginal children hospitalization rates were not statistically different across all levels of socio-economic disadvantage. Hospitalizations for TTI among non-Aboriginal children were more common among those from higher socio-economic backgrounds. This was also true for Aboriginal children; however, the difference was not statistically significant. There was a decline in OM hospitalization rates between 1998 and 2005 and remained stable thereafter.

Conclusion

Aboriginal children and children from lower socio-economic backgrounds were over-represented with OM-related hospitalizations but had fewer TTIs. Despite a decrease in OM and TTI hospitalization rates during the first half of the study for all groups, the disparity between Aboriginal and non-Aboriginal children and between those of differing socioeconomic deprivation remained.

Predictors of pneumococcal carriage and the effect of the 13-valent pneumococcal conjugate vaccination in the Western Australian Aboriginal population

Background

The 7-valent pneumococcal conjugate vaccine (PCV7) was introduced to prevent invasive pneumococcal disease (IPD) in Western Australian (WA) Aboriginal people in 2001. PCV13 replaced PCV7 in July 2011, covering six additional pneumococcal serotypes; however, IPD rates remained high in Aboriginal people in WA. Upper respiratory tract pneumococcal carriage can precede IPD, and PCVs alter serotype distribution.

Methods

To assess the impact of PCV13 introduction, identify emerging serotypes, and assess risk factors for carriage, nasopharyngeal swabs and information on demographic characteristics, health, medication and living conditions from Aboriginal children and adults across WA from August 2008 to November 2014 were collected. Bacteria were cultured using selective media and pneumococcal isolates were serotyped by Quellung reaction. Risk factors were analysed by multivariable logistic regression.

Results

One thousand five hundred swabs pre- and 1385 swabs post-PCV13 introduction were collected. Pneumococcal carriage was detected in 66.8% of children <5 years old and 53.2% of 5–14 year-olds post-PCV13, compared with pre-PCV13 prevalence of 72.2% and 49.4%, respectively. The prevalence of PCV13-non-PCV7 serotypes decreased in children <5 years old from 13.5% pre-PCV13 to 5.8% post-PCV13 (p < 0.01), and from 8.4% to 6.1% in children 5–14 years old (p > 0.05). The most common serotypes post-PCV13 were 11A (prevalence 4.0%), 15B (3.5%), 16F (3.5%), and 19F (3.2%).

Risk of detection of pneumococcal carriage increased until age 12 months (odds ratio [OR] 4.19, 95% confidence interval [CI] 2.39–7.33), with nasal discharge (OR 2.49 [95% CI 2.00–3.09]), residence in a remote community (OR 2.21 [95% CI 1.67–2.92]) and household crowding (OR 1.36 [95% CI 1.11–1.67]). Recent antibiotic use was negatively associated with pneumococcal carriage (OR 0.48 [95% CI 0.33–0.69]). Complete resistance to penicillin was present among isolates of serotypes 19A (6.0%), 19F (2.3%) and non-serotypeable isolates (1.9%). Serotype 23F and newly emerged serotype 7B isolates showed high rates of resistance to cotrimoxazole, erythromycin and tetracycline (86.9%, 86.9%, 82.0%, respectively for 23F, 100.0%, 100.0% and 93.3% for 7B).

Conclusion

Since PCV13 replaced PCV7, carriage of PCV13-non-PCV7 serotypes decreased significantly among children <5 years old, those most likely to have received PCV13, and to a lesser extent in older people. Known risk factors for carriage including crowding and young age remain in the Aboriginal population.

Virulence determinants of Moraxella catarrhalis: distribution and considerations for vaccine development

Moraxella catarrhalis is a human-restricted opportunistic bacterial pathogen of the respiratory mucosa. It frequently colonizes the nasopharynx asymptomatically, but is also an important causative agent of otitis media (OM) in children, and plays a significant role in acute exacerbations of chronic obstructive pulmonary disease (COPD) in adults. As the current treatment options for M. catarrhalis infection in OM and exacerbations of COPD are often ineffective, the development of an efficacious vaccine is warranted. However, no vaccine candidates for M. catarrhalis have progressed to clinical trials, and information regarding the distribution of M. catarrhalis virulence factors and vaccine candidates is inconsistent in the literature. It is largely unknown if virulence is associated with particular strains or subpopulations of M. catarrhalis, or if differences in clinical manifestation can be attributed to the heterogeneous expression of specific M. catarrhalis virulence factors in the circulating population. Further investigation of the distribution of M. catarrhalis virulence factors in the context of carriage and disease is required so that vaccine development may be targeted at relevant antigens that are conserved among disease-causing strains. The challenge of determining which of the proposed M. catarrhalis virulence factors are relevant to human disease is amplified by the lack of a standardized M. catarrhalis typing system to facilitate direct comparisons of worldwide isolates. Here we summarize and evaluate proposed relationships between M. catarrhalis subpopulations and specific virulence factors in the context of colonization and disease, as well as the current methods used to infer these associations.

Microbiology of otitis media in Indigenous Australian children: review

Objectives:

To review research addressing the polymicrobial aetiology of otitis media in Indigenous Australian children in order to identify research gaps and inform best practice in effective prevention strategies and therapeutic interventions.

Methods:

Literature review.

Results:

Studies of aspirated middle-ear fluid represented a minor component of the literature reviewed. Most studies relied upon specimens from middle-ear discharge or the nasopharynx. Culture-based middle-ear discharge studies have found that non-typeableHaemophilus influenzaeandStreptococcus pneumoniaepredominate, withMoraxella catarrhalis, Staphylococcus aureusandStreptococcus pyogenesisolated in a lower proportion of samples.Alloiococcus otitidiswas detected in a number of studies; however, its role in otitis media pathogenesis remains controversial. Nasopharyngeal colonisation is a risk factor for otitis media in Indigenous infants, and bacterial load of otopathogens in the nasopharynx can predict the ear state of Indigenous children.

Conclusion:

Most studies have used culture-based methods and specimens from middle-ear discharge or the nasopharynx. Findings from these studies are consistent with international literature, but reliance on culture may incorrectly characterise the microbiology of this condition. Advances in genomic technologies are now providing microbiologists with the ability to analyse the entire mixed bacterial communities (‘microbiomes’) of samples obtained from Indigenous children with otitis media.

No evidence for impaired humoral immunity to pneumococcal proteins in Australian Aboriginal children with otitis media

BACKGROUND

The Australian Aboriginal population experiences disproportionately high rates of otitis media (OM). Streptococcus pneumoniae is one of the main pathogens responsible for OM and currently no vaccine offering cross strain protection exists. Vaccines consisting of conserved antigens to S. pneumoniae may reduce the burden of OM in high-risk populations; however no data exists examining naturally acquired antibody in Aboriginal children with OM.

METHODS

Serum and salivary IgA and IgG were measured against the S. pneumoniae antigens PspA1 and 2, CbpA and Ply in a cross sectional study of 183 children, including 36 non-Aboriginal healthy control children and 70 Aboriginal children and 77 non-Aboriginal children undergoing surgery for OM using a multiplex bead assay.

RESULTS

Significant differences were observed between the 3 groups for serum anti-PspA1 IgA, anti-CbpA and anti-Ply IgG and for all salivary antibodies assessed. Aboriginal children with a history of OM had significantly higher antibody titres than non-Aboriginal healthy children with no history of OM and non-Aboriginal children with a history of OM for several proteins in serum and saliva. Non-Aboriginal children with a history of OM had significantly higher salivary anti-PspA1 IgG than healthy children, while all other titres were comparable between the groups.

CONCLUSIONS

Conserved vaccine candidate proteins from S. pneumoniae induce serum and salivary antibody responses in Aboriginal and non-Aboriginal children with a history of OM. Aboriginal children do not have an impaired antibody response to the antigens measured from S. pneumoniae and they may represent vaccine candidates in Indigenous populations.

A multi-centre open-label randomised non-inferiority trial comparing watchful waiting to antibiotic treatment for acute otitis media without perforation in low-risk urban Aboriginal and Torres Strait Islander children (the WATCH trial): study protocol for a randomised controlled trial

Background

Treatment guidelines recommend watchful waiting for children older than 2 years with acute otitis media (AOM) without perforation, unless they are at high risk of complications. The high prevalence of chronic suppurative otitis media (CSOM) in remote Aboriginal and Torres Strait Islander communities leads these children to be classified as high risk. Urban Aboriginal and Torres Strait Islander children are at lower risk of complications, but evidence to support the subsequent recommendation for watchful waiting in this population is lacking.

Methods/Design

This non-inferiority multi-centre randomised controlled trial will determine whether watchful waiting is non-inferior to immediate antibiotics for urban Aboriginal and Torres Strait Islander children with AOM without perforation. Children aged 2 − 16 years with AOM who are considered at low risk for complications will be recruited from six participating urban primary health care services across Australia. We will obtain informed consent from each participant or their guardian. The primary outcome is clinical resolution on day 7 (no pain, no fever of at least 38 °C, no bulging eardrum and no complications of AOM such as perforation or mastoiditis) as assessed by general practitioners or nurse practitioners. Participants and outcome assessors will not be blinded to treatment. With a sample size of 198 children in each arm, we have 80 % power to detect a non-inferiority margin of up to 10 % at a significance level of 5 %, assuming clinical improvement of at least 80 % in both groups. Allowing for a 20 % dropout rate, we aim to recruit 495 children.

We will analyse both by intention-to-treat and per protocol. We will assess the cost- effectiveness of watchful waiting compared to immediate antibiotic prescription. We will also report on the implementation of the trial from the perspectives of parents/carers, health professionals and researchers.

Discussion

The trial will provide evidence for the safety and effectiveness of watchful waiting for the management of AOM in Aboriginal and Torres Strait Islander children living in urban settings who are considered to be at low risk of complications.

Trial registration

The trial is registered with Australia New Zealand Clinical Trials Registry (ACTRN12613001068752). Date of registration: 24 September 2013.

Sweep frequency impedance measures in Australian Aboriginal and Caucasian neonates

OBJECTIVE

Despite high prevalence of otitis media in Aboriginal children, the acoustic-mechanical properties of their outer and middle ear during the neonatal period remain obscured. The objective of this study was to compare the acoustic-mechanical properties of outer and middle ear using Sweep Frequency Impedance (SFI) measures between Australian Aboriginal and Caucasian neonates.

METHODS

SFI data from 40 ears of 24 Aboriginal neonates (16 males, 8 females) with mean gestational age of 39.57 weeks (SD = 1.25) and 160 ears of 119 Caucasian neonates (57 males, 62 females) with mean gestational age of 39.28 weeks (SD = 1.25) serving as controls were analysed. SFI data in terms of resonance frequency (RF) and mobility of the outer and middle ear (ΔSPL) were collected from neonates who passed a test battery that included automated auditory brainstem response, distortion product otoacoustic emissions test and 1000-Hz tympanometry. SFI data were analysed using descriptive statistics and analysis of variance.

RESULTS

There was no significant difference in mean gestational age, age of testing and birth weight between the Aboriginal and Caucasian neonates. The mean resonance frequencies for the outer ear (mean RF1 = 264.9 Hz, SD = 58.6 Hz) and middle ear (mean RF2 = 1144 Hz, SD = 228.8 Hz) for Aboriginal neonates were significantly lower than that of Caucasian neonates (mean RF1 = 295.3 Hz, SD = 78.4 Hz and mean RF2 = 1241.8 Hz, SD = 216.6 Hz). However, no significant difference in the mobility of outer ear (ΔSPL1) and middle ear (ΔSPL2) between the two groups was found. Middle ear resonance was absent in 22.5% (9 ears) of Aboriginal ears but present in all Caucasian ears.

CONCLUSIONS

This study provided evidence that despite passing the test battery, Aboriginal neonates had significantly lower resonance frequencies of the outer and middle ear than Caucasian neonates. Furthermore, 22.5% of Aboriginal neonates showed no middle ear resonance, indicating the possibility of subtle middle ear issues not detected by the test battery. Reasons for the different acoustic-mechanical properties between the two ethnic groups remain unclear and require further investigation.

Diversity of nontypeable Haemophilus influenzae strains colonizing Australian Aboriginal and non-Aboriginal children

Nontypeable Haemophilus influenzae (NTHI) strains are responsible for respiratory-related infections which cause a significant burden of disease in Australian children. We previously identified a disparity in NTHI culture-defined carriage rates between Aboriginal and non-Aboriginal children (42% versus 11%). The aim of this study was to use molecular techniques to accurately determine the true NTHI carriage rates (excluding other culture-identical Haemophilus spp.) and assess whether the NTHI strain diversity correlates with the disparity in NTHI carriage rates. NTHI isolates were cultured from 595 nasopharyngeal aspirates collected longitudinally from asymptomatic Aboriginal (n=81) and non-Aboriginal (n=76) children aged 0 to 2 years living in the Kalgoorlie-Boulder region, Western Australia. NTHI-specific 16S rRNA gene PCR and PCR ribotyping were conducted on these isolates. Confirmation of NTHI by 16S rRNA gene PCR corrected the NTHI carriage rates from 42% to 36% in Aboriginal children and from 11% to 9% in non-Aboriginal children. A total of 75 different NTHI ribotypes were identified, with 51% unique to Aboriginal children and 13% unique to non-Aboriginal children (P<0.0001). The strain richness (proportion of different NTHI ribotypes) was similar for Aboriginal (19%, 65/346) and non-Aboriginal children (19%, 37/192) (P=0.909). Persistent carriage of the same ribotype was rare in the two groups, but colonization with multiple NTHI strains was more common in Aboriginal children than in non-Aboriginal children. True NTHI carriage was less than that estimated by culture. The Aboriginal children were more likely to carry unique and multiple NTHI strains, which may contribute to the chronicity of NTHI colonization and subsequent disease.

Otitis media in Indigenous Australian children: review of epidemiology and risk factors

Background:

Otitis media represents a major health concern in Australian Indigenous children (‘Indigenous children’), which has persisted, despite public health measures, for over 30 years.

Methods:

Global searches were performed to retrieve peer-reviewed and ‘grey’ literature investigating the epidemiology of and risk factors for otitis media in Indigenous children, published between 1985 and 2012.

Results:

In Indigenous children, the prevalence of otitis media subtypes is 7.1–12.8 per cent for acute otitis media, 10.5–30.3 per cent for active chronic otitis media and 31–50 per cent for tympanic membrane perforation. The initial onset of otitis media in Indigenous children occurs earlier and persists for longer after the first year of life, compared with non-Indigenous children. Indigenous children are colonised by otopathogens more frequently, at younger ages and with a higher bacterial load. Poor community and domestic infrastructure, overcrowding and exposure to tobacco smoke increase the risk of otitis media in Indigenous children; however, the availability of swimming pools plays no role in the prevention or management of otitis media.

Conclusion:

Despite awareness of the epidemiological burden of otitis media and its risk factors in Indigenous children, studies undertaken since 1985 demonstrate that otitis media remains a significant public health concern in this population.

High nasopharyngeal carriage of non-vaccine serotypes in Western Australian aboriginal people following 10 years of pneumococcal conjugate vaccination

BACKGROUND

Invasive pneumococcal disease (IPD) continues to occur at high rates among Australian Aboriginal people. The seven-valent pneumococcal conjugate vaccine (7vPCV) was given in a 2-4-6-month schedule from 2001, with a 23-valent pneumococcal polysaccharide vaccine (23vPPV) booster at 18 months, and replaced with 13vPCV in July 2011. Since carriage surveillance can supplement IPD surveillance, we have monitored pneumococcal carriage in western Australia (WA) since 2008 to assess the impact of the 10-year 7vPCV program.

METHODS

We collected 1,500 nasopharyngeal specimens from Aboriginal people living in varied regions of WA from August 2008 until June 2011. Specimens were cultured on selective media. Pneumococcal isolates were serotyped by the quellung reaction.

RESULTS

Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were carried by 71.9%, 63.2% and 63.3% respectively of children <5 years of age, and 34.6%, 22.4% and 27.2% of people ≥5 years. Of 43 pneumococcal serotypes identified, the most common were 19A, 16F and 6C in children <5 years, and 15B, 34 and 22F in older people. 7vPCV serotypes accounted for 14.5% of all serotypeable isolates, 13vPCV for 32.4% and 23vPPV for 49.9%, with little variation across all age groups. Serotypes 1 and 12F were rarely identified, despite causing recent IPD outbreaks in WA. Complete penicillin resistance (MIC ≥2µg/ml) was found in 1.6% of serotype 19A (5.2%), 19F (4.9%) and 16F (3.2%) isolates and reduced penicillin susceptibility (MIC ≥0.125µg/ml) in 24.9% of isolates, particularly 19F (92.7%), 19A (41.3%), 16F (29.0%). Multi-resistance to cotrimoxazole, tetracycline and erythromycin was found in 83.0% of 23F isolates. Among non-serotypeable isolates 76.0% had reduced susceptibility and 4.0% showed complete resistance to penicillin.

CONCLUSIONS

Ten years after introduction of 7vPCV for Aboriginal Australian children, 7vPCV serotypes account for a small proportion of carried pneumococci. A large proportion of circulating serotypes are not covered by any currently licensed vaccine.

Association between early bacterial carriage and otitis media in Aboriginal and non-Aboriginal children in a semi-arid area of Western Australia: a cohort study

Background

Streptococcus pneumoniae (Pnc), nontypeable Haemophilus influenzae (NTHi) and Moraxella catarrhalis (Mcat) are the most important bacterial pathogens associated with otitis media (OM). Previous studies have suggested that early upper respiratory tract (URT) bacterial carriage may increase risk of subsequent OM. We investigated associations between early onset of URT bacterial carriage and subsequent diagnosis of OM in Aboriginal and non-Aboriginal children living in the Kalgoorlie-Boulder region located in a semi-arid zone of Western Australia.

Methods

Aboriginal and non-Aboriginal children who had nasopharyngeal aspirates collected at age 1- < 3 months and at least one clinical examination for OM by an ear, nose and throat specialist before age 2 years were included in this analysis. Tympanometry to detect middle ear effusion was also performed at 2- to 6-monthly scheduled field visits from age 3 months. Multivariate regression models were used to investigate the relationship between early carriage and subsequent diagnosis of OM controlling for environmental factors.

Results

Carriage rates of Pnc, NTHi and Mcat at age 1- < 3 months were 45%, 29% and 48%, respectively, in 66 Aboriginal children and 14%, 5% and 18% in 146 non-Aboriginal children. OM was diagnosed at least once in 71% of Aboriginal children and 43% of non-Aboriginal children. After controlling for age, sex, presence of other bacteria and environmental factors, early nasopharyngeal carriage of NTHi increased the risk of subsequent OM (odds ratio = 3.70, 95% CI 1.22-11.23) in Aboriginal children, while Mcat increased the risk of OM in non-Aboriginal children (odds ratio = 2.63, 95% CI 1.32-5.23). Early carriage of Pnc was not associated with increased risk of OM.

Conclusion

Early NTHi carriage in Aboriginal children and Mcat in non-Aboriginal children is associated with increased risk of OM independent of environmental factors. In addition to addressing environmental risk factors for carriage such as overcrowding and exposure to environmental tobacco smoke, early administration of pneumococcal-Haemophilus influenzae D protein conjugate vaccine to reduce bacterial carriage in infants, may be beneficial for Aboriginal children; such an approach is currently being evaluated in Australia.

Otitis media: viruses, bacteria, biofilms and vaccines

Otitis media typically presents as either acute otitis media (AOM), with symptoms including fever, otalgia, otorrhoea or irritability and short duration; or as otitis media with effusion (OME), which is often asymptomatic and characterised by accumulation of fluid in the middle ear.

Diagnostic certainty of otitis media is challenging, given the young age of patients and variability of symptoms.

Otitis media predominantly occurs as coincident to viral upper respiratory tract infections and/or bacterial infections.

Common viruses that cause upper respiratory tract infection are frequently associated with AOM and new‐onset OME. These include respiratory syncytial virus, rhinovirus, adenovirus, parainfluenza and coronavirus.

Predominant bacteria that cause otitis media are Streptococcus pneumoniae, Moraxella catarrhalis, and non‐typeable Haemophilus influenzae.

Antibiotic therapy does not significantly benefit most patients with AOM, but long‐term prophylactic antibiotic therapy can reduce the risk of otitis media recurrence among children at high risk.

In Australia, 84% of AOM is treated with antibiotic therapy, which contributes to development of antibiotic resistance.

Vaccine development is a key future direction for reducing the world burden of otitis media, but requires polymicrobial formulation and ongoing monitoring and modification to ensure sustained reduction in disease burden.

The impact of otitis media on cognitive and educational outcomes

Otitis media is a common disease in childhood that can adversely affect cognitive and educational outcomes. The literature in this area is equivocal, and findings may be influenced by research design. The impact of otitis media on individual children's development appears to depend on the inter-relationship between several factors. Children who have early-onset otitis media (under 12 months) are at high risk of developing long-term speech and language problems. Otitis media has been found to interact negatively with pre-existing cognitive or language problems. For biological or environmental reasons, some populations have a pattern of early onset, higher prevalence and episodes of longer duration; this pattern leads to a higher risk of long-term speech and language problems. These factors suggest that Indigenous children may be at higher risk of cognitive and educational sequelae than non-Indigenous children.

New horizons: otitis media research in Australia

Otitis media affects nearly all children worldwide. Despite an enormous amount of research, our understanding of this common condition continues to be challenged. New pathogens involved in otitis media are still being identified. The importance of interactions between viral and bacterial infection and the role of new vaccines need to be clarified. The proposal that bacteria can become more resistant to therapy through biofilm formation and intracellular infection could have important implications for treatment. The most important clinical research findings have been summarised in systematic reviews. In developed countries, research supporting "watchful waiting" of otitis media with effusion and acute otitis media have had most impact on evidence-based clinical practice guidelines. Indigenous Australian children remain at risk of more severe otitis media. Research programs targeting this population have been well supported. Unfortunately, interventions that can dramatically improve outcomes have remained elusive. For children at high risk of otitis media, health care services should concentrate on accurate diagnosis, antibiotic treatment of suppurative infections, and scheduled follow-up of affected children. Despite the lack of recent studies, strategies to minimise the impact the hearing loss associated with otitis media are important. Improvements in education, hygiene practices, and living conditions are likely to reduce the incidence and severity of otitis media. Studies of these types of interventions are needed.