Otitis media in Australian Aboriginal children: an overview

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.

Inter-rater agreement between 13 otolaryngologists to diagnose otitis media in Aboriginal and Torres Strait Islander children using a telehealth approach

INTRODUCTION

Telehealth programs are important to deliver otolaryngology services for Aboriginal and Torres Strait Islander children living in rural and remote areas, where distance and access to specialists is a critical factor.

OBJECTIVE

To evaluate the inter-rater agreement and value of increasing levels of clinical data (otoscopy with or without audiometry and in-field nurse impressions) to diagnose otitis media using a telehealth approach.

DESIGN

Blinded, inter-rater reliability study.

SETTING

Ear health and hearing assessments collected from a statewide telehealth program for Indigenous children living in rural and remote areas of Queensland, Australia.

PARTICIPANTS

Thirteen board-certified otolaryngologists independently reviewed 80 telehealth assessments from 65 Indigenous children (mean age 5.7 ± 3.1 years, 33.8% female).

INTERVENTIONS

Raters were provided increasing tiers of clinical data to assess concordance to the reference standard diagnosis: Tier A) otoscopic images alone, Tier B) otoscopic images plus tympanometry and category of hearing loss, and Tier C) as B plus static compliance, canal volume, pure-tone audiometry, and nurse impressions (otoscopic findings and presumed diagnosis). For each tier, raters were asked to determine which of the four diagnostic categories applied: normal aerated ear, acute otitis media (AOM), otitis media with effusion (OME), and chronic otitis media (COM).

MAIN OUTCOME MEASURES

Proportion of agreement to the reference standard, prevalence-and-bias adjusted κ coefficients, mean difference in accuracy estimates between each tier of clinical data.

RESULTS

Accuracy between raters and the reference standard increased with increased provision of clinical data (Tier A: 65% (95%CI: 63-68%), κ = 0.53 (95%CI: 0.48-0.57); Tier B: 77% (95%CI: 74-79%), 0.68 (95%CI: 0.65-0.72); C: 85% (95%CI: 82-87%), 0.79 (95%CI: 0.76-0.82)). Classification accuracy significantly improved between Tier A to B (mean difference:12%, p < 0.001) and between Tier B to C (mean difference: 8%, p < 0.001). The largest improvement in classification accuracy was observed between Tier A and C (mean difference: 20%, p < 0.001). Inter-rater agreement similarly improved with increasing provision of clinical data.

CONCLUSIONS

There is substantial agreement between otolaryngologists to diagnose ear disease using electronically stored clinical data collected from telehealth assessments. The addition of audiometry, tympanometry and nurse impressions significantly improved expert accuracy and inter-rater agreement, compared to reviewing otoscopic images alone.

An Artificial Intelligence Computer-vision Algorithm to Triage Otoscopic Images From Australian Aboriginal and Torres Strait Islander Children

OBJECTIVE

To develop an artificial intelligence image classification algorithm to triage otoscopic images from rural and remote Australian Aboriginal and Torres Strait Islander children.

STUDY DESIGN

Retrospective observational study.

SETTING

Tertiary referral center.

PATIENTS

Rural and remote Aboriginal and Torres Strait Islander children who underwent tele-otology ear health screening in the Northern Territory, Australia between 2010 and 2018.

INTERVENTIONS

Otoscopic images were labeled by otolaryngologists to classify the ground truth. Deep and transfer learning methods were used to develop an image classification algorithm.

MAIN OUTCOME MEASURES

Accuracy, sensitivity, specificity, positive predictive value, negative predictive value, area under the curve (AUC) of the resultant algorithm compared with the ground truth.

RESULTS

Six thousand five hundred twenty seven images were used (5927 images for training and 600 for testing). The algorithm achieved an accuracy of 99.3% for acute otitis media, 96.3% for chronic otitis media, 77.8% for otitis media with effusion (OME), and 98.2% to classify wax/obstructed canal. To differentiate between multiple diagnoses, the algorithm achieved 74.4 to 92.8% accuracy and an AUC of 0.963 to 0.997. The most common incorrect classification pattern was OME misclassified as normal tympanic membranes.

CONCLUSIONS

The paucity of access to tertiary otolaryngology care for rural and remote Aboriginal and Torres Strait Islander communities may contribute to an under-identification of ear disease. Computer vision image classification algorithms can accurately classify ear disease from otoscopic images of Indigenous Australian children. In the future, a validated algorithm may integrate with existing telemedicine initiatives to support effective triage and facilitate early treatment and referral.

The impact of hearing impairment on early academic achievement in Aboriginal children living in remote Australia: a data linkage study

Background

The prevalence of otitis media (OM) and related hearing loss has remained persistently high among some groups of Australian Aboriginal children who are also reported to have poor academic outcomes. The general literature remains inconclusive about the association between OM-related hearing loss and academic performance in primary school. This study aimed to investigate this association in Aboriginal children living in the Northern Territory (NT) of Australia.

Methods

A retrospective, observational cohort study was conducted for 2208 NT Aboriginal children, aged about 8 years, living in remote and very remote communities. The explanatory variable was audiometrically determined hearing level as recorded in the Remote Hearing Assessment dataset. The outcome variable consisted of scale scores in the five domains of the National Assessment Program – Literacy and Numeracy (NAPLAN) for Year 3. Other linked datasets used in the study included school attendance records, perinatal records and community level information on relative remoteness, socioeconomic disadvantage and housing crowdedness. Fixed effects linear regression models were used for statistical analyses.

Results

Compared with children with normal hearing and after controlling for a range of covariates, children with mild hearing impairment (HI) scored lower in Writing and Spelling by 15.0 points (95% CI: − 22.4 to − 7.6, p < 0.0005) and 5.0 points (95% CI: − 9.6 to − 0.3, p = 0.037), equivalent to 7.3 and 2.1% of the mean score, respectively. Children with moderate or worse HI scored lower in Writing and Numeracy by 13.4 points (95% CI, − 24.8 to − 1.9, p = 0.022) and 15.2 points (95% CI, − 27.6 to − 2.7, p = 0.017), both equivalent to 6.3% of the mean score the respective domain. Other factors associated with poorer NAPLAN results included being male, lower Year 2 school attendance, low birthweight, average household size> 5 persons, living in a very remote community and speaking English as a second language.

Conclusions

OM-related HI was independently associated with poorer early year academic achievement in Aboriginal children living in remote NT communities. Interventions to improve academic outcomes for Aboriginal children must incorporate actions to address the negative impact associated with HI through early detection, effective treatment and ongoing support for affected children.

The Impact of Hearing Impairment on the Life Trajectories of Aboriginal Children in Remote Australia: Protocol for the Hearing Loss in Kids Project

BACKGROUND

Previous studies have reported a high prevalence of chronic otitis media (OM) and hearing impairment (HI) in Aboriginal children in the Northern Territory (NT) of Australia. Children affected by these disorders are believed to be at increased risk for adverse outcomes in early childhood development, school attendance, academic performance, and child maltreatment and youth offending. However, to date, there have been no studies quantifying the association between HI and these outcomes in this population.

OBJECTIVE

This study will investigate the association between HI and the 5 outcomes in Aboriginal children living in remote NT communities.

METHODS

Individual-level information linked across multiple administrative datasets will be used to conduct a series of retrospective observational studies on selected developmental and school outcomes. The predictor variables for all studies are the results from audiometric hearing assessments. The outcome measures are as follows: Australian Early Development Census results, representing developmental readiness for school, assessed around 5 years of age; Year 1 school attendance rates; Year 3 school-based academic performance, assessed in the National Assessment Program-Literacy and Numeracy; incidence of child maltreatment events (including both notifications and substantiated cases); and incidence of a first guilty verdict for youth offenders. Confounding and moderating factors available for the analysis include both community-level factors (including school fixed effects, socioeconomic status, level of remoteness, and housing crowdedness) and individual-level factors (including maternal and perinatal health and hospital admissions in early childhood).

RESULTS

The study commenced in 2018, with ethics and data custodian approvals for data access and linkage. This has enabled the completion of data linkage and the commencement of data analysis for individual component studies, with findings expected to be published in 2019 and 2020.

CONCLUSIONS

This study will provide first evidence of the impact of OM-related HI on the developmental, educational, and social outcomes of Australian Aboriginal children. The findings are expected to have significant implications for policy development, service design, and resource allocation.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR1-10.2196/15464.

Developmental vulnerability of Australian school-entry children with hearing loss

National data from the Australian Early Development Census (AEDC) was used to describe the sociodemographic and developmental characteristics of a cohort of Australian children entering their first year of primary school in 2012. Results, together with sociodemographic variables were reported for two groups: children with and without reported hearing loss. Data on 285232 children were analysed, with just over 1% of these children identified with hearing loss. Logistic regression analysis found that children with reported hearing loss had over double the odds than their hearing peers of being developmentally 'vulnerable' on one or more domains of the AEDC. Covariates of interest included Aboriginal and Torres Strait Islander heritage, as well as high rates of school absenteeism. Retrospective longitudinal research linking developmental outcomes with intervention efforts, such as newborn hearing screening, would be beneficial in future research.

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.

The impact of hearing impairment on Aboriginal children's school attendance in remote Northern Territory: a data linkage study

OBJECTIVE

To investigate the association between hearing impairment (HI) and Year 1 school attendance in Aboriginal children in the Northern Territory (NT) of Australia.

METHODS

Observational cohort study (n=3,744) by analysing linked individual-level information for Aboriginal children from the NT Government school attendance records, NT Perinatal Register and Remote Hearing Assessment dataset, and community level data for relative remoteness, socioeconomic disadvantage and housing crowdedness.

RESULTS

Children with unilateral hearing loss, mild HI and moderate or worse HI had significantly lower Year 1 attendance than those with normal hearing, attending 5.6 (95%CI, -9.10 ∼-2.10), 4.0 (95%CI, -7.17 ∼-0.90) and 6.1 (95%CI, -10.71 ∼-1.49) days fewer, respectively. Other variables that yielded significant association were: male gender, having attended preschool less than 20% of available days, speaking English as second language, twin birth and average household size >5.

CONCLUSIONS

Aboriginal children with any level of HI are likely to have lower school attendance rates in Year 1 than their peers with normal hearing. Implications for public health: In this population, where the prevalence of otitis media and accompanying HI remains extremely high, the early detection and management of hearing loss on entry into primary school should be included in the measures to improve school attendance.

Povidone-iodine ear wash and oral cotrimoxazole for chronic suppurative otitis media in Australian aboriginal children: study protocol for factorial design randomised controlled trial

Background

Chronic suppurative otitis media (CSOM) is a significant health issue affecting Aboriginal Australians. Long-term hearing loss can cause communication problems, educational disadvantage, and social isolation. Current standard treatment for CSOM in our region is twice daily dry mopping of the pus from the ear canal followed by instillation of ciprofloxacin antibiotic ear drops for up to 16 weeks, or until the discharge resolves for a period of 3 days. The treatment is long, laborious and fails to resolve ear discharge in 70% of cases in remote communities. Bacterial pathogens also persist. Povidone-iodine ear wash is the preferred method of clearing ear discharge in Western Australia. However, evidence of its effectiveness is lacking. In systematic reviews, topical antibiotics (ciprofloxacin) have been shown to be more effective than oral antibiotics or topical antiseptics. Currently, it is unclear whether there are any benefits of combining these treatments.

Methods

This protocol describes a 2 × 2 factorial randomised controlled trial of two different interventions (povidone-iodine ear wash and oral cotrimoxazole), given as adjunctive therapy to standard treatment for CSOM. 280 children, between 2 months and 17 years of age, Indigenous or non-Indigenous, living in participating Northern Territory (NT) communities are randomised to standard treatment (dry mopping and ciprofloxacin drops) plus one of two topical treatments (dilute povidone-iodine ear wash or no wash) and one of two oral medication treatments (16 weeks of cotrimoxazole or placebo).

Discussion

Current treatment of CSOM in our region shows that eradication of bacterial pathogens from the middle ear space and dry ears is often not achieved. This trial will evaluate the efficacy of adjunctive treatments of antiseptic ear washes and oral antibiotics. Clinical, microbiological and hearing outcomes will be reported.

Trial registration

This trial (ACTRN12614000234617) was registered with ANZCTR on 05 April 2014.

Preventative and medical treatment of ear disease in remote or resource-constrained environments

BACKGROUND

Important ear problems can affect the outer ear, the middle ear and the inner ear. Globally, the greatest burden of disease is due to ear conditions that are associated with otorrhoea and hearing loss.

METHODS

This study reviewed the literature on the prevention and treatment of common ear conditions that are most relevant to settings with high rates of ear disease and limited resources. The grading of recommendations assessment, development and evaluation ('GRADE') approach was utilised to assess interventions.

RESULTS

Accurate diagnosis of ear disease is challenging. Much of the preventable burden of ear disease is associated with otitis media. Nine otitis media interventions for which there is moderate to high certainty of effect were identified. While most interventions only provide modest benefit, the impact of treatment is more substantial in children with acute otitis media with perforation and chronic suppurative otitis media.

CONCLUSION

Disease prevention through good hygiene practices, breastfeeding, reducing smoke exposure, immunisation and limiting noise exposure is recommended. Children with acute otitis media with perforation, chronic suppurative otitis media, complications of otitis media, and significant hearing loss should be prioritised for medical treatment.

An innovative approach to improve ear, nose and throat surgical access for remote living Cape York Indigenous children

INTRODUCTION

On a background of high rates of severe otitis media (OM) with associated hearing loss, children from the Torres Strait and Cape York region requiring ear, nose and throat (ENT) surgery, faced waiting times exceeding three years. After numerous clinical safety incidents were raised, indicating a failure of the current system to deliver appropriate care, the governing Hospital and Health service opted to deliver surgical care through an alternate process. ENT surgeries were performed on 16 consented children from two remote locations via the private health care system, funded by a health provider partnership.

METHODS

We examined the collaboration processes alongside clinical findings from this ENT surgery. Collated patient data, included patient demographics, clinical and audiometry presentation features were reviewed and compared pre and post-operatively. Cost savings associated with the use of TeleHealth post-operatively were briefly examined.

RESULTS

Surgeries were successfully completed in all 16 children. The reported mean waitlist time for ENT surgery was 1.2 years. Pre-surgery pure-tone average hearing thresholds were reported at left: 30.9 dB, right: 38.2 dB. The majority of presentations were for bilateral OM with Effusion (69%). Post-surgical follow up indicated successful clinical outcomes in 80% of patients and successful hearing outcomes in 88% of patients. Mean difference pure-tone average hearing thresholds, left: 8.4 dB and right: 11.2 dB. Furthermore, the majority of patients reported improved hearing and breathing. The use of TeleHealth for post-operative review enabled a minimum cost saving of AUD$21,664 for these 16 children. Overall, a high level of staffing resources was required to successfully coordinate this intense surgical activity.

CONCLUSION

This innovative approach to a health system crisis enabled successful ENT surgical and hearing outcomes in 16 children, whose waitlisted time grossly exceeded state health recommendations. Using private health facilities funded by a health partnership, while unlikely to be a suitable model of care for routine service delivery; may be applied as an adjunct service model when blockages and delays lead to sub-standard service provision. This approach may be applicable to other health care facilities when facing extended elective surgery wait times in ENT or other specialty areas.

Cost-Effectiveness Analysis of a Mobile Ear Screening and Surveillance Service versus an Outreach Screening, Surveillance and Surgical Service for Indigenous Children in Australia

Indigenous Australians experience a high rate of ear disease and hearing loss, yet they have a lower rate of service access and utilisation compared to their non-Indigenous counterparts. Screening, surveillance and timely access to specialist ear, nose and throat (ENT) services are key components in detecting and preventing the recurrence of ear diseases. To address the low access and utilisation rate by Indigenous Australians, a collaborative, community-based mobile telemedicine-enabled screening and surveillance (MTESS) service was trialled in Cherbourg, the third largest Indigenous community in Queensland, Australia. This paper aims to evaluate the cost-effectiveness of the MTESS service using a lifetime Markov model that compares two options: (i) the Deadly Ears Program alone (current practice involving an outreach ENT surgical service and screening program), and (ii) the Deadly Ears Program supplemented with the MTESS service. Data were obtained from the Deadly Ears Program, a feasibility study of the MTESS service and the literature. Incremental cost-utility ratios were calculated from a societal perspective with both costs (in 2013–14 Australian dollars) and quality-adjusted life years (QALYs) discounted at 5% annually. The model showed that compared with the Deadly Ears Program, the probability of an acceptable cost-utility ratio at a willingness-to-pay threshold of $50,000/QALY was 98% for the MTESS service. This cost effectiveness arises from preventing hearing loss in the Indigenous population and the subsequent reduction in associated costs. Deterministic and probability sensitivity analyses indicated that the model was robust to parameter changes. We concluded that the MTESS service is a cost-effective strategy. It presents an opportunity to resolve major issues confronting Australia’s health system such as the inequitable provision and access to quality healthcare for rural and remotes communities, and for Indigenous Australians. Additionally, it may encourage effective health service delivery at a time when the healthcare funding and workforce capacity are limited.

Prevalence of fetal alcohol syndrome in a population-based sample of children living in remote Australia: the Lililwan Project

AIM

Aboriginal leaders concerned about high rates of alcohol use in pregnancy invited researchers to determine the prevalence of fetal alcohol syndrome (FAS) and partial fetal alcohol syndrome (pFAS) in their communities.

METHODS

Population-based prevalence study using active case ascertainment in children born in 2002/2003 and living in the Fitzroy Valley, in Western Australia (April 2010-November 2011) (n = 134). Socio-demographic and antenatal data, including alcohol use in pregnancy, were collected by interview with 127/134 (95%) consenting parents/care givers. Maternal/child medical records were reviewed. Interdisciplinary assessments were conducted for 108/134 (81%) children. FAS/pFAS prevalence was determined using modified Canadian diagnostic guidelines.

RESULTS

In 127 pregnancies, alcohol was used in 55%. FAS or pFAS was diagnosed in 13/108 children, a prevalence of 120 per 1000 (95% confidence interval 70-196). Prenatal alcohol exposure was confirmed for all children with FAS/pFAS, 80% in the first trimester and 50% throughout pregnancy. Ten of 13 mothers had Alcohol Use Disorders Identification Test scores and all drank at a high-risk level. Of children with FAS/pFAS, 69% had microcephaly, 85% had weight deficiency and all had facial dysmorphology and central nervous system abnormality/impairment in three to eight domains.

CONCLUSIONS

The population prevalence of FAS/pFAS in remote Aboriginal communities of the Fitzroy Valley is the highest reported in Australia and similar to that reported in high-risk populations internationally. Results are likely to be generalisable to other age groups in the Fitzroy Valley and other remote Australian communities with high-risk alcohol use during pregnancy. Prevention of FAS/pFAS is an urgent public health challenge.

Indigenous Respiratory Outreach Care: the first 18 months of a specialist respiratory outreach service to rural and remote Indigenous communities in Queensland, Australia

OBJECTIVE

Respiratory diseases are a leading cause of morbidity and mortality in Indigenous Australians. However, there are limited approaches to specialist respiratory care in rural and remote communities that are culturally appropriate. A specialist Indigenous Respiratory Outreach Care (IROC) program, developed to address this gap, is described.

METHODS

The aim of the present study was to implement, pilot and evaluate multidisciplinary specialist respiratory outreach medical teams in rural and remote Indigenous communities in Queensland, Australia. Sites were identified based on a perception of unmet need, burden of respiratory disease and/or capacity to use the clinical service and capacity building for support offered.

RESULTS

IROC commenced in March 2011 and, to date, has been implemented in 13 communities servicing a population of approximately 43000 Indigenous people. Clinical service delivery has been possible through community engagement and capacity building initiatives directed by community protocols.

CONCLUSION

IROC is a culturally sensitive and sustainable model for adult and paediatric specialist outreach respiratory services that may be transferrable to Indigenous communities across Queensland and Australia.

Impact of swimming on chronic suppurative otitis media in Aboriginal children: a randomised controlled trial

OBJECTIVES

To measure the impact of 4 weeks of daily swimming on rates of ear discharge among Aboriginal children with a tympanic membrane perforation (TMP) and on the microbiology of the nasopharynx and middle ear.

DESIGN, SETTING AND PARTICIPANTS

A randomised controlled trial involving 89 Aboriginal children (aged 5-12 2013s) with a TMP, conducted in two remote Northern Territory Aboriginal communities from August to December 2009.

INTERVENTION

4 school weeks of daily swimming lessons (45 minutes) in a chlorinated pool.

MAIN OUTCOME MEASURES

Proportions of children with ear discharge and respiratory and opportunistic bacteria in the nasopharynx and middle ear.

RESULTS

Of 89 children randomly assigned to the swimming or non-swimming groups, 58 (26/41 swimmers and 32/48 non-swimmers) had ear discharge at baseline. After 4 weeks, 24 of 41 swimmers had ear discharge compared with 32 of 48 non-swimmers (risk difference, - 8% (95% CI, - 28% to 12%). There were no statistically significant changes in the microbiology of the nasopharynx or middle ear in swimmers or non-swimmers. Streptococcus pneumoniae and non-typeable Haemophilus influenzae were the dominant organisms cultured from the nasopharynx, and H. influenzae, Staphylococcus aureus and Pseudomonas aeruginosa were the dominant organisms in the middle ear.

CONCLUSIONS

Swimming lessons for Aboriginal children in remote communities should be supported, but it is unlikely that they will substantially reduce rates of chronic suppurative otitis media and associated bacteria in the nasopharynx and middle ear. However, swimming was not associated with increased risk of ear discharge and we found no reason to discourage it.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN12613000634774.

Longitudinal analysis of ear infection and hearing impairment: findings from 6-year prospective cohorts of Australian children

Background

Middle ear infection is common in childhood. Despite its prevalence, there is little longitudinal evidence about the impact of ear infection, particularly its association to hearing loss. By using 6-year prospective data, we investigate the onset and impact over time of ear infection in Australian children.

Methods

We analyse 4 waves of the Longitudinal Study of Australian Children (LSAC) survey collected in 2004, 2006, 2008, and 2010. There are two age cohorts in this study (B cohort aged 0/1 to 6/7 years N=4242 and K cohort aged 4/5 to 10/11 years N=4169). Exposure was parent-reported ear infection and outcome was parent-reported hearing problems. We modelled ear infection onset and subsequent impact on hearing using multivariate logistic regressions, reporting Adjusted Odds Ratios (AOR) and Confidence Intervals (95% CI). Separate analyses were reported for indigenous and non-indigenous children.

Results

Associations of ear infections between waves were found to be very strong both among both indigenous and non-indigenous children in the two cohorts. Reported ear infections at earlier wave were also associated with hearing problems in subsequent wave. For example, reported ear infections at age 4/5 years among the K cohort were found to be predictors of hearing problems at age 8/9 years (AOR 4.0, 95% CI 2.2-7.3 among non-indigenous children and AOR 7.7 95% CI 1.0-59.4 among indigenous children). Number of repeated ear infections during the 6-year follow-up revealed strong dose–response relationships with subsequent hearing problems among non-indigenous children (AORs ranged from 4.4 to 31.7 in the B cohort and 4.4 to 51.0 in the K cohort) but not statistically significant among indigenous children partly due to small sample.

Conclusions

This study revealed the longitudinal impact of ear infections on hearing problems in both indigenous and non-indigenous children. These findings highlight the need for special attention and follow-up on children with repeated ear infections.

The impact of housing improvement and socio-environmental factors on common childhood illnesses: a cohort study in Indigenous Australian communities

Background

Improvements in health are an important expected outcome of many housing infrastructure programs. The authors aimed to determine if improvement in the notoriously poor housing infrastructure in Australian Indigenous communities results in reduction in common childhood illness and to identify important mediating factors in this relationship.

Methods

The authors conducted a prospective cohort study of 418 children aged 7 years or younger in 10 Australian Indigenous communities, which benefited most substantially from government-funded housing programs over 2004–2005. Data on functional and hygienic state of houses, reports of common childhood illness and on socio-economic conditions were collected through inspection of household infrastructure and interviews with children's carers and householders.

Results

After adjustment for a range of potential confounding variables, the analysis showed no consistent reduction in carers' reporting of common childhood illnesses in association with improvements in household infrastructure, either for specific illnesses or for these illnesses in general. While there was strong association between improvement in household infrastructure and improvement of hygienic condition of the house, there were only marginal improvements in crowding.

Conclusions

High levels of household crowding and poor social, economic and environmental conditions in many Australian Indigenous communities appear to place major constraints on the potential for building programs to impact on the occurrence of common childhood illness. These findings reinforce the need for building programs to be supported by a range of social, behavioural and community-wide environmental interventions in order for the potential health gains of improved housing to be more fully realised.

Less germs, less mucus, less snot: teachers' and health workers' perceptions of the benefits and barriers of ear health programs in lower primary school classes

This study explored health and education professionals' perceptions of the health benefits and barriers of different ear health programs used in lower primary school classes in two district education areas in the Goldfields South East Health Region, Western Australia. Health and education staff providing services to children in kindergarten to year three primary school classes were sent a questionnaire about ear health programs provided in their school. Sixty-one questionnaires were returned from 43 teachers, 14 community health nurses, three Aboriginal health workers and one teacher's assistant. Some schools implemented all the ear health programs examined at all year levels while others implemented only one of the programs. Teachers, community health nurses and Aboriginal health workers identified that all ear health programs were beneficial to students. Reported physical health benefits included reduced ear infections, early detection of ear infections and improved hearing. Behavioural benefits included improved concentration, alertness and attention in the classroom. Barriers to implementing the programs were obtaining consent from parents/carers, student transience and attendance, time to implement and conduct the programs and human and physical resources. Evaluation methods used varied from no evaluation for the Breathe Blow Cough and tissue spearing programs to limited data collection for audiometry, otoscopy and ear toilet programs. Respondents perceived that ear health programs were effective in improving health and behavioural outcomes for children. A formal pre-post evaluation to provide objective data to confirm this is needed to inform policy around this important health issue.

Theories of otitis media pathogenesis, with a focus on Indigenous children

Otitis media is a common childhood illness associated with hearing loss, social disadvantage and medical costs. Prevalence and severity are high among Indigenous children. Respiratory bacterial and viral pathogens ascend the eustachian tube from the nasopharynx to the middle ear, causing inflammation, fluid accumulation, and bulging of the tympanic membrane, with or without pain. Among Australian Indigenous children, ear disease commences earlier in life, and involves multiple strains of bacterial pathogens at high density that persist longer. Persistent nasal discharge, overcrowded living conditions (particularly exposure to many children) and poor facilities for washing children perpetuate a vicious cycle of transmission and infection. Risk factors include environmental tobacco smoke, season, lack of breastfeeding, younger age and immature immune system, and possibly genetic factors. The innate immune system is a critical first response to infection, particularly as passive maternal antibodies decline and during the maturation of the infant adaptive immune response. The relative contributions of innate factors to protection from otitis media are currently not well understood. A diversity of antibodies that target strain-specific and conserved antigens are generated in response to natural exposure to otitis media pathogens (or to vaccines). Deficiencies in these antibodies may explain susceptibility to recurrent infections. Incremental contributions from all these elements are likely to be important in otitis media susceptibility versus protection. Effective medical and social strategies to prevent early age of onset are urgently needed.

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.

Exploring cross-sectional associations between common childhood illness, housing and social conditions in remote Australian Aboriginal communities

Background

There is limited epidemiological research that provides insight into the complex web of causative and moderating factors that links housing conditions to a variety of poor health outcomes. This study explores the relationship between housing conditions (with a primary focus on the functional state of infrastructure) and common childhood illness in remote Australian Aboriginal communities for the purpose of informing development of housing interventions to improve child health.

Methods

Hierarchical multi-level analysis of association between carer report of common childhood illnesses and functional and hygienic state of housing infrastructure, socio-economic, psychosocial and health related behaviours using baseline survey data from a housing intervention study.

Results

Multivariate analysis showed a strong independent association between report of respiratory infection and overall functional condition of the house (Odds Ratio (OR) 3.00; 95%CI 1.36-6.63), but no significant association between report of other illnesses and the overall functional condition or the functional condition of infrastructure required for specific healthy living practices. Associations between report of child illness and secondary explanatory variables which showed an OR of 2 or more included: for skin infection - evidence of poor temperature control in the house (OR 3.25; 95%CI 1.06-9.94), evidence of pests and vermin in the house (OR 2.88; 95%CI 1.25-6.60); for respiratory infection - breastfeeding in infancy (OR 0.27; 95%CI 0.14-0.49); for diarrhoea/vomiting - hygienic state of food preparation and storage areas (OR 2.10; 95%CI 1.10-4.00); for ear infection - child care attendance (OR 2.25; 95%CI 1.26-3.99).

Conclusion

These findings add to other evidence that building programs need to be supported by a range of other social and behavioural interventions for potential health gains to be more fully realised.

10-valent pneumococcal nontypeable Haemophilus influenzae PD conjugate vaccine: Synflorix

The global burden of disease due to Streptococcus pneumoniae remains high. The licensed 7-valent pneumococcal conjugate vaccine (7vCRM, Prevenar/Prevnar) has successfully reduced invasive disease in the USA, but serotype coverage is incomplete and some evidence suggests that serotype replacement has occurred. Recently, a new 10-valent pneumococcal nontypeable Haemophilus influenzae (NTHi) protein D (PD) conjugate vaccine (PHiD-CV, Synflorix) has been licensed in more than 40 countries, including Europe, for the prevention of invasive disease and acute otitis media (AOM) due to pneumococcus in infants and children. PHiD-CV is immunogenic in infants when administered as a three-dose primary vaccination in a range of schedules and has a safety profile comparable to that of 7vCRM. Additional serotypes in PHiD-CV (1, 5 and 7F) increase overall serotype coverage and improve coverage in specific age groups and against specific disease syndromes. The use of the PD carrier, which provided protection against AOM caused by NTHi in a large efficacy trial testing a prototype of the final vaccine formulation, suggests that PHiD-CV will also provide some protection against AOM due to NTHi.

Effectiveness of 7-valent pneumococcal conjugate vaccine against radiologically diagnosed pneumonia in indigenous infants in Australia

OBJECTIVE

To evaluate the effectiveness of the 7-valent pneumococcal conjugate vaccine (PCV7) in preventing pneumonia, diagnosed radiologically according to World Health Organization (WHO) criteria, among indigenous infants in the Northern Territory of Australia.

METHODS

We conducted a historical cohort study of consecutive indigenous birth cohorts between 1 April 1998 and 28 February 2005. Children were followed up to 18 months of age. The PCV7 programme commenced on 1 June 2001. All chest X-rays taken within 3 days of any hospitalization were assessed. The primary endpoint was a first episode of WHO-defined pneumonia requiring hospitalization. Cox proportional hazards models were used to compare disease incidence.

FINDINGS

There were 526 pneumonia events among 10,600 children - an incidence of 3.3 per 1000 child-months; 183 episodes (34.8%) occurred before 5 months of age and 247 (47.0%) by 7 months. Of the children studied, 27% had received 3 doses of vaccine by 7 months of age. Hazard ratios for endpoint pneumonia were 1.01 for 1 versus 0 doses; 1.03 for 2 versus 0 doses; and 0.84 for 3 versus 0 doses.

CONCLUSION

There was limited evidence that PCV7 reduced the incidence of radiologically confirmed pneumonia among Northern Territory indigenous infants, although there was a non-significant trend towards an effect after receipt of the third dose. These findings might be explained by lack of timely vaccination and/or occurrence of disease at an early age. Additionally, the relative contribution of vaccine-type pneumococcus to severe pneumonia in a setting where multiple other pathogens are prevalent may differ with respect to other settings where vaccine efficacy has been clearly established.

Failure to vaccinate or failure of vaccine? Effectiveness of the 23-valent pneumococcal polysaccharide vaccine program in Indigenous adults in the Northern Territory of Australia

Over the last decade, there has been no discernible reduction in Invasive Pneumococcal Disease (IPD) amongst Indigenous adults in the Northern Territory (NT) of Australia, despite increasing vaccination coverage. We examined the utility of two common methods, the screening method and the indirect method, to determine the 23-valent pneumococcal polysaccharide vaccine effectiveness (VE) in prevention of IPD amongst Indigenous adults in this setting. VE was calculated for the period 2001-2005 across two distinct geographical areas where the disease burden was known to differ. VE against vaccine-type IPD was 3.4% (95% CI -43, 35) for the NT. However, population vaccination coverage varied widely according to geographical region and where this was within the range appropriate for the use of the screening method, VE was within the expected range (67.2%, 95% CI 47, 80). VE according to the indirect cohort appeared unreliable in this setting due to the analysis being based on a very limited number of non-vaccine-type IPD cases. Surveillance based estimates of VE such as these need to be considered with caution, but the results suggest failure to vaccinate is the most likely reason vaccine-type IPD has not reduced in this setting.

Acute and chronic otitis media

Otitis media (OM) is a common illness in young children. OM has historically been associated with frequent and severe complications. Nowadays it is usually a mild condition that often resolves without treatment. For most children, progression to tympanic membrane perforation and chronic suppurative OM is unusual (low-risk populations); this has led to reevaluation of many interventions that were used routinely in the past. Evidence from a large number of randomized controlled trials can help when discussing treatment options with families. Indigenous children in the United States, Canada, Northern Europe, Australia, and New Zealand experience more OM than other children. In some places, Indigenous children continue to suffer from the most severe forms of the disease. Communities with more than 4% of the children affected by chronic tympanic membrane perforation have a major public health problem (high-risk populations). Higher rates of invasive pneumococcal disease, pneumonia, and chronic suppurative lung disease (including bronchiectasis) are also seen. These children will often benefit from effective treatment of persistent (or recurrent) bacterial infection.

Recent advances in otitis media

Otitis media (OM) is a pervasive illness in infants and children, and many children suffer multiple episodes during the first years of life. High rates of acute otitis media (AOM) are reported in developed and emerging countries. Early onset is common in both settings. Recurrent OM is associated with several factors, including early onset of disease, having a sibling with a history of AOM and absence of breast-feeding. Early onset disease has been hypothesized to result from Eustachian tube dysfunction, immunologic naivete and immaturity, and viral upper respiratory tract infection. Nasopharyngeal colonization with bacterial otopathogens increases the likelihood of AOM and the disease is most frequent in children with viral respiratory tract infection colonized with multiple otopathogens (Streptococcus pneumoniae, nontypeable Haemophilus influenzae [NTHi], Moraxella catarrhalis), potentially as a result of inflammation resulting from competition among the bacterial species within the nasopharynx. Epidemiologic observations and studies of pathogenesis suggest that successful strategies for reducing the burden of disease will be best accomplished by targeting multiple viral and/or bacterial pathogens and preventing early onset disease. Guidelines (2004) for the treatment of AOM in children establish a clear hierarchy among the various antibacterials for the treatment of this disease. Failure to achieve early bacterial eradication during antibiotic therapy for AOM increases the clinical failure rates in AOM in young children. Most recurrent AOM episodes occurring within 1 month after successful completion of antibiotic therapy are due to new otopathogens. Failure to eradicate middle ear and/or nasopharyngeal pathogens is associated with higher rates of clinical recurrent AOM, even when the patients show clinical improvement or cure at the end of therapy for the initial episode. Optimal strategy for the prevention of AOM recurrences requires sterilization of the middle ear and eradication of nasopharyngeal carriage of otopathogens during antimicrobial therapy.

Global serotype distribution among Streptococcus pneumoniae isolates causing otitis media in children: potential implications for pneumococcal conjugate vaccines

Acute otitis media (AOM) is the most common infection following pneumococcal colonization of the upper respiratory tract. Streptococcus pneumoniae causes 30-60% of AOM cases worldwide. However, not all pneumococcal serotypes cause disease and an association exists with nasopharyngeal colonization by certain serotypes and their propensity to cause AOM. This review examines the global serotype distribution relationship between pneumococcal serotypes and AOM in children aged <18 years and demonstrates that the most common pneumococcal serotypes causing AOM globally are 3, 6A, 6B, 9V, 14, 19A, 19F, and 23F.

Tympanometry of a diverse group of preschool aged children

OBJECTIVE

Ethnicity has been previously described as a risk factor for middle ear disease. Little data exist on the presence of middle ear disease based on tympanometry screening comparing Asian children and children of other races.

METHODS

Two hundred and seventy children aged 3-5 were screened with tympanometry at six Head Start sites in St. Paul, Minnesota during the months of September and October of 2004. Gender, age, and race/ethnicity was recorded and entered into a database, along with values for canal volume, static admittance, peak pressure, and tympanometric width.

RESULTS

Criteria for abnormal tympanometry were based on American Speech-Language Hearing Association (ASHA) recommendations for a failed tympanogram for 1-5 year olds (admittance <0.3 mmho or width >200 daPa). There were no statistically significant differences in failure rates between males and females. There were, however, more failures for Asian (predominantly Hmong) children compared to children of other races/ethnicities after adjusting for age and gender differences (OR=6.39, CI 3.65-11.2, p<0.001) and for children <4-years-old compared to children 4-5-years-old after adjusting for race and gender differences (OR=1.99, CI 1.03-3.84, p<0.05).

CONCLUSIONS

Asian children were more than six times as likely to fail tympanometry as children of other races/ethnicities. The explanation for this difference is likely to be multifactorial, and further research is needed to characterize this difference.

Otitis media in young Aboriginal children from remote communities in Northern and Central Australia: a cross-sectional survey

BACKGROUND

Middle ear disease (otitis media) is common and frequently severe in Australian Aboriginal children. There have not been any recent large-scale surveys using clear definitions and a standardised middle ear assessment. The aim of the study was to determine the prevalence of middle ear disease (otitis media) in a high-risk population of young Aboriginal children from remote communities in Northern and Central Australia.

METHODS

709 Aboriginal children aged 6-30 months living in 29 communities from 4 health regions participated in the study between May and November 2001. Otitis media (OM) and perforation of the tympanic membrane (TM) were diagnosed by tympanometry, pneumatic otoscopy, and video-otoscopy. We used otoscopic criteria (bulging TM or recent perforation) to diagnose acute otitis media.

RESULTS

914 children were eligible to participate in the study and 709 were assessed (78%). Otitis media affected nearly all children (91%, 95%CI 88, 94). Overall prevalence estimates adjusted for clustering by community were: 10% (95%CI 8, 12) for unilateral otitis media with effusion (OME); 31% (95%CI 27, 34) for bilateral OME; 26% (95%CI 23, 30) for acute otitis media without perforation (AOM/woP); 7% (95%CI 4, 9) for AOM with perforation (AOM/wiP); 2% (95%CI 1, 3) for dry perforation; and 15% (95%CI 11, 19) for chronic suppurative otitis media (CSOM). The perforation prevalence ranged from 0-60% between communities and from 19-33% between regions. Perforations of the tympanic membrane affected 40% of children in their first 18 months of life. These were not always persistent.

CONCLUSION

Overall, 1 in every 2 children examined had otoscopic signs consistent with suppurative ear disease and 1 in 4 children had a perforated tympanic membrane. Some of the children with intact tympanic membranes had experienced a perforation that healed before the survey. In this high-risk population, high rates of tympanic perforation were associated with high rates of bulging of the tympanic membrane.

Early radiographic and clinical features associated with bronchiectasis in children

Bronchiectasis among children living in developing regions is associated with respiratory infections during early childhood, but specific risk factors that precede childhood bronchiectasis are not fully characterized. We hypothesized that severe respiratory syncytial viral (RSV) infection in infancy would increase the risk of bronchiectasis among Alaska Native children in rural Alaska. This was a follow-up cohort study of a 1993-1996 case-control study of RSV-hospitalized case patients and their controls. For each 5-8-year-old former case-patient and control subject, we reviewed medical records, interviewed parents, performed physical examinations and spirometry, collected sera, and analyzed all historical chest radiographs. Ten (11%) RSV cases and 10 (9%) controls had radiographic evidence of bronchiectasis. The mean age at radiographic diagnosis of bronchiectasis was 3.3 years (range, 1.2-6.1 years). Children were more likely to develop bronchiectasis if their chest radiographs, when they were < 2 years of age, showed lung parenchymal densities (RR = 3.9, P < 0.013), persistent parenchymal densities > 6 months' duration (RR = 3.0, P = 0.02), or infiltrates on multiple episodes (test for trend, P = 0.003). Radiographic features of hyperinflation and atelectasis among children < 2 years old were not associated with eventual bronchiectasis. A single severe infection with RSV alone did not predispose Alaska Native infants to bronchiectasis. Childhood bronchiectasis was associated with lung and hence airway injury, manifested on radiographs by parenchymal densities or "pneumonia" rather than by hyperinflation or atelectasis.

In vitro antimicrobial susceptibility of Brachyspira pilosicoli isolates from humans

The in vitro antimicrobial susceptibility of the anaerobic intestinal spirochete Brachyspira pilosicoli was investigated by an agar dilution method. Human (n = 123) and porcine (n = 16) isolates were susceptible to metronidazole, ceftriaxone, meropenem, tetracycline, moxifloxacin, and chloramphenicol; erythromycin and ciprofloxacin were not active. Resistance to amoxicillin and clindamycin varied. Amoxicillin susceptibility was restored by clavulanic acid.

Non-CF bronchiectasis: clinical and HRCT evaluation

Childhood bronchiectasis not related to underlying disease is still common in some populations in affluent countries. The aims of the study were to: 1) describe demographics, 2) evaluate the effectiveness of routine investigations, and 3) determine the relationship between spirometry and radiology scoring systems, in children with chronic suppurative lung disease (CSLD) living in Central Australia. Data of children living in Central Australia aged </=15 years with noncystic fibrosis CSLD were identified over 2 years. Chest high-resolution computed tomography (HRCT) scans were interpreted by a pediatric radiologist and scored according to three systems. Sixty-five children were identified, resulting in a prevalence of at least 14.7/1,000 aboriginal children aged </=15 years. Comorbidities (most common: suppurative otitis media in >70%) and early hospitalisation for pneumonia were common (median age, 0.5 years). Previous admissions for pneumonia were almost universally present and significantly more common than bronchiolitis (95% CI for proportional difference, 0.4-0.51). Although the majority did not have a treatable underlying cause, investigations had significant impact on management in 12.3% of children. None of the chest HRCT scores related to any spirometry data. In conclusion, CSLD is unacceptably common in indigenous children of this region, commences early in life, and is associated with significant comorbidities. Spirometry data do not reflect the severity of lung disease in HRCT scans. While improvement in the living standards is of utmost importance, the medical management that includes thorough investigations of these children should not be neglected.

Analysis of penicillin-binding protein genes of clinical isolates of Streptococcus pneumoniae with reduced susceptibility to amoxicillin

The recent emergence of pneumococcal isolates exhibiting an unusual resistance phenotype of higher amoxicillin MICs in relation to the penicillin MICs prompted an analysis of the pbp genes from three such strains isolated in France. For comparison, three amoxicillin-susceptible strains were included in the study. DNA sequence analysis of the pbp2x, pbp2b, and pbp1a genes revealed extensive sequence divergence in all six isolates compared to the sequences of the genes of penicillin-susceptible strain R6. With the exception of pbp2b, no amino acid mutations were unique to the resistant isolates. Transformation experiments with cloned pbp genes isolated from one of the resistant isolates demonstrated a stepwise development of amoxicillin resistance involving penicillin-binding proteins (PBPs) 2X, 2B, and 1A. Full resistance, equivalent to that of the donor strain, was achieved only when genomic DNA was transformed into R6(2x/2b/1a) mutants, suggesting that full resistance development in this isolate is mediated by a non-PBP determinant. Moreover, the recently identified murMN resistance determinant does not appear to have any impact on resistance in this isolate. This determinant (from the French isolate) was, however, able to transform an R6 mutant harboring pbp2x, pbp2b, and pbp1a genes from a Hungarian clone with an extremely high level of penicillin resistance so that it had increased levels of penicillin resistance. These results indicate that the development of high-level beta-lactam resistance is a complex process and that the involvement of MurMN in penicillin resistance appears to be dependent on specific mutations in PBPs 2X, 2B, and/or 1A. Furthermore, an additional (as yet unidentified) non-PBP-mediated resistance determinant is required for full resistance development in some pneumococci.

Risk factor associations with wheezing patterns in children followed longitudinally from birth to 3(1/2) years

BACKGROUND

There is a paucity of detailed longitudinal data on wheeze in early childhood. Not all children who wheeze in early infancy will continue to wheeze into childhood and beyond. This study aims to investigate possible risk factors for different patterns of wheeze in the pre-school years.

SUBJECTS AND METHODS

Study participants were part of the Avon Longitudinal Study of Parents and Children (ALSPAC). Maternal reports of child wheeze between birth and 6 months and again between 30 and 42 months were gathered prospectively. Children were categorized into early wheeze, persistent wheeze or late onset wheeze. A large number of risk factors were assessed for each wheezing phenotype using multivariable logistic regression models.

RESULTS

Over 70% of children who wheezed in the first 6 months did not wheeze 3 years later. Wheezing between 0-6 months was independently associated with the presence of older siblings, male sex, delivery between April and December, bottle feeding, young maternal age, prenatal tobacco smoke exposure, atopy and parental history of asthma. From within this group of early wheezers, risk factors for wheeze that persisted beyond 6 months included pre-term delivery, young maternal age, living in rented local authority housing, atopy and a maternal (not paternal) history of asthma. Atopy and a family history of asthma emerged as the main predictors of wheeze that developed after 6 months of age.

CONCLUSION

It is clear that a number of wheezing syndromes exist by 3(1/2) years, albeit with some degree of overlap. Detailed follow-up of this cohort is underway to determine whether risk factor associations determined in the first 3(1/2) years have long-term significance for the clinical entity termed 'asthma'.

The future impact of societal and cultural factors on parasitic disease -- some emerging issues

A variety of societal and cultural factors will increase host exposure or susceptibility to infectious agents, particularly parasites. Such factors have already had a major impact on the emergence of infectious diseases and the situation is likely to worsen further as we enter the new millennium. The changes that are enhancing the spread and transmission of parasitic diseases, as well as those which are adversely affecting host responsiveness, are examined with reference to specific parasites.

Expression of two novel proteins in Chlamydia trachomatis during natural infection

Genes for a putative membrane associated protein (mvi -homologue) and a 48 kDa protein (ctr48) in Chlamydia trachomatis were characterized. The mvi -homologue has 12 transmembrane domains and shows considerable homology to the members of this gene family in various organisms. The ctr48 has a leader sequence and the C-proximal half is tryptophan-rich. The latter region shares 65% identity with the N-proxima third of C. pneumoniae 76 kDa protein over an overlap of 231 amino acid residues. The genes for the mvi -homologue and the ctr48 are present in the B, Ba, D, E, J and L2 serotypes of C. trachomatis. Immediately downstream from the ctr48 gene are multiple stop codons which are followed by a functional rho-independent terminator. The mvi -homologue and ctr48 genes are independently transcribed, albeit poorly in serotype B. However, protein products corresponding to these genes could not be detected by western blotting in HEp2 cells infected with C. trachomatis. Nevertheless, antibodies to peptides corresponding to these proteins were detected in sera with high micro-immunofluorescence titre against C. trachoImatic, collected from a Chlamydia -endemic population. These results suggest that the mvi -homologue and ctr48 are expressed by C. trachomatis during natural infection.