Tea tree oil for the management of scabies in Aboriginal and Torres Strait Islander children: A pilot randomised controlled trial
Scabies affects about 6 in 10 Aboriginal and Torres Strait Islander children in Australia at any given time, more than six times the rate seen in the rest of the developed world. It also predisposes affected children to renal and rheumatic heart disease. In an international first, our research will trial a simple and low-cost treatment against paediatric scabies and associated secondary bacterial skin infection, using a topical formulation containing tea tree oil. Should the results be positive, this would provide evidence for a simple, affordable and effective treatment for a population with a significant public health burden. This project builds on the team's previous clinical work in this area. Scabies was listed as a neglected tropical disease by the World Health Organization in 2013. The burden of scabies is quite high in Indigenous children: around 69% of Indigenous children have had scabies diagnosed before their first birthday, with a median of three presentations per child (IQR [Inter-quartile range] 1–5) in the first year of life alone (NT data). Although scabies control mass treatment programs in Indigenous communities (locally and internationally) have had positive results, it has been acknowledged that it is difficult to maintain the mass treatment protocols over many years and termination of protocol leads to treatment failure. Permethrin (topical agent, cream formulation) is the slowest acting scabicide in the region due to scabies mites developing resistance to the treatment (in vitro observation). On the other hand, administration of ivermectin (sole oral therapy) is labour intensive so it is not feasible to administer it to households in large communities (and therefore not recommended for treating household contacts).
At present, there is a clear need for a treatment strategy to meet the long-term treatment objectives (i.e. effective control of scabies infestation). If a TTO-containing formulation is shown to be effective for the treatment of scabies, we are confident that this will result in significant reduction of associated morbidity (secondary bacterial infection) and long-term benefits such as reduced kidney diseases, rheumatic heart diseases and cost savings. Even more importantly, if proven effective, TTO has the potential to be administered by non-health professionals in the community over time. This would prevent many children from needing hospitalisation resulting from scabies-driven complications, resulting in far-reaching outcomes among the Indigenous communities within Australia and internationally. The team expects to develop a simple and effective treatment that does not require direct supervision by a trained health worker, and which can be used in households among larger communities where there might be protracted health and social benefits. This community empowerment strategy will potentially lead to other community and population health interventions gaining traction in remote Indigenous populations.
Control of scabies and its associated complications in the Indigenous population is a public health priority in Australia due to its high prevalence and significant morbidity and mortality. This work is consistent with the priorities for Aboriginal and Torres Strait Islander health research as laid out in the NHMRC Road Map II. Ultimately, this work aims to reduce the life expectancy gap between Indigenous and non-Indigenous Australians. The team is committed to a whole-of-life approach in closing this gap, and in particular is interested in effective strategies for addressing the substantially increased burden of infection-related morbidity among Aboriginal children.
Tangible Benefits and Impact of the research to Australian Indigenous Communities
In previous projects (scabies, skin sores), participants, Indigenous reference groups and other Indigenous community members have reinforced to researchers the importance they place on the healthy start to life of children, and a conviction of the concept that health outcomes in adulthood have their origins throughout the lifespan including childhood. The work proposed here will build on a substantial body of Aboriginal child health research by the team, which has had as its focus the identification of readily implementable treatment and preventive strategies, mostly in childhood infection. The research team has previously quantified the antimicrobial and scabicidal effects of TTO and its potential usefulness in the management of scabies infestation in this population. Earlier work has demonstrated that scabies underlies up to 70% of secondary bacterial skin infections (streptococcal; pyoderma) and disease rates of Aboriginal Australians are among the highest in the world. The team's earlier work revealed the future uncertainty (resulting from drug resistance leading to treatment failures) of currently available scabicidal preparations in Australia. This calls for a newer treatment approach with an agent (e.g. TTO) which has general (scabicidal) and non-specific (antibacterial, anti-inflammatory and wound healing) effects for the management of scabies infestation and associated secondary bacterial infections, to reduce the residual disease burden in the Indigenous community.
The proposed project will co-create new knowledge that contributes to the health, wellbeing, and commercial returns of the Australian Indigenous community. It will do this by strengthening community and other partnerships, encouraging strategic collaboration, facilitating shared infrastructure, developing the next generation of medical scientists and other healthcare professionals, and promoting the value of knowledge exchange between industry, community and academia.
The proposed project is also likely to benefit research for the Health Research Institute and the Health Precinct in areas related to applied and translational impact and knowledge exchange. In the longer term, there is also the potential for commercialisation and significant economic and societal benefits for the Indigenous community, should the outcomes of the proposed project be successful.
Dr Jackson Thomas, Project Leader
Assistant Professor, Pharmacy
Faculty of Health
University of Canberra
T: +61 (0) 2 6206 8928