Otitis media (OM) is one of the most common paediatric illnesses for which medical advice is sought in developed countries. Australian Aboriginal children suffer high rates of OM from early infancy. The resultant hearing loss can affect education and quality of life. As numerous factors contribute to the burden of OM, interventions aimed at reducing the impact of single risk factors are likely to fail. To identify key risk factors and understand how they interact in complex causal pathways, we followed 100 Aboriginal and 180 non-Aboriginal children from birth to age 2 years in a semi-arid zone of Western Australia. We collected demographic, obstetric, socio-economic and environmental data, breast milk once, and nasopharyngeal samples and saliva on seven occasions. Ear health was assessed by clinical examination, tympanometry, transient evoked otoacoustic emissions and audiometry. We considered the conduct of our study in relation to national ethical guidelines for research in Aboriginal and Torres Strait Islander health. After 1 year of community consultation, the study was endorsed by local committees and ethical approval granted. Fieldwork was tailored to minimise disruption to people's lives and we provided regular feedback to the community. We saw 81% of non-Aboriginal and 65% of Aboriginal children at age 12 months. OM was diagnosed on 55% and 26% of routine clinical examinations in Aboriginal and non-Aboriginal children respectively. Aboriginal mothers were younger and less educated, fewer were employed and they lived in more crowded conditions than non-Aboriginal mothers. Sixty-four per cent of Aboriginal and 40% of non-Aboriginal babies were exposed to environmental tobacco smoke. Early consultation, provision of a service while undertaking research, inclusion of Aboriginal people as active members of a research team and appropriate acknowledgement will assist in ensuring successful completion of the research.

Since responsibility for treatment may not lie with the biological mother, awareness campaigns must target the entire community. As early OM may be asymptomatic, health personnel should be encouraged to do otoscopy on all children with non-specific symptoms.

Renal stones have been reported as a common finding in Australian Aboriginal children. The stones are predominantly urate in composition. We report on five children with nephrolithiasis from the Goldfields region of Western Australia. All were diagnosed when under 5 years of age, the majority being under 3 years. All five children also had lactose intolerance, and we postulate that carbohydrate malabsorption, together with the ensuing chronic diarrhoea and intraluminal breakdown of sugars by enteric bacteria may result in a situation of chronic metabolic acidosis. Chronic metabolic acidosis can lead to protein catabolism, increased urate excretion and the formation of renal stones. Carbohydrate intolerance may be an aetiological factor in the development of renal stones and possibly chronic renal disease, particularly in Aboriginal Australians. Renal disease represents one of the most significant factors affecting the health of Australian Aboriginal people. The incidence of end stage renal failure in this population exceeds that of non-Aboriginals by a factor of 13:1, and this disproportionate figure is increasing. It is likely that chronic renal damage is multifactorial; however, it is probable that at least some aetiological factors have their onset during childhood.