Disease burden and health-care clinic attendances for young children in remote aboriginal communities of northern Australia

The epidemiology of superficial Streptococcal A (impetigo and pharyngitis) infections in Australia: A systematic review

BACKGROUND

Streptoccocal A (Strep A, GAS) infections in Australia are responsible for significant morbidity and mortality through both invasive (iGAS) and post-streptococcal (postGAS) diseases as well as preceding superficial (sGAS) skin and throat infection. The burden of iGAS and postGAS are addressed in some jurisdictions by mandatory notification systems; in contrast, the burden of preceding sGAS has no reporting structure, and is less well defined. This review provides valuable, contemporaneous evidence on the epidemiology of sGAS presentations in Australia, informing preventative health projects such as a Streptococcal A vaccine and standardisation of primary care notification.

METHODS AND FINDINGS

MEDLINE, Scopus, EMBASE, Web of Science, Global Health, Cochrane, CINAHL databases and the grey literature were searched for studies from an Australian setting relating to the epidemiology of sGAS infections between 1970 and 2020 inclusive. Extracted data were pooled for relevant population and subgroup analysis. From 5157 titles in the databases combined with 186 grey literature reports and following removal of duplicates, 4889 articles underwent preliminary title screening. The abstract of 519 articles were reviewed with 162 articles identified for full text review, and 38 articles identified for inclusion. The majority of data was collected for impetigo in Aboriginal and Torres Strait Islander populations, remote communities, and in the Northern Territory, Australia. A paucity of data was noted for Aboriginal and Torres Strait Islander people living in urban centres or with pharyngitis. Prevalence estimates have not significantly changed over time. Community estimates of impetigo point prevalence ranged from 5.5-66.1%, with a pooled prevalence of 27.9% [95% CI: 20.0-36.5%]. All studies excepting one included >80% Aboriginal and Torres Strait Islander people and all excepting two were in remote or very remote settings. Observed prevalence of impetigo as diagnosed in healthcare encounters was lower, with a pooled estimate of 10.6% [95% CI: 3.1-21.8%], and a range of 0.1-50.0%. Community prevalence estimates for pharyngitis ranged from 0.2-39.4%, with a pooled estimate of 12.5% [95% CI: 3.5-25.9%], higher than the prevalence of pharyngitis in healthcare encounters; ranging from 1.0-5.0%, and a pooled estimate of 2.0% [95% CI: 1.3-2.8%]. The review was limited by heterogeneity in study design and lack of comparator studies for some populations.

CONCLUSIONS

Superficial Streptococcal A infections contribute to an inequitable burden of disease in Australia and persists despite public health interventions. The burden in community studies is generally higher than in health-services settings, suggesting under-recognition, possible normalisation and missed opportunities for treatment to prevent postGAS. The available, reported epidemiology is heterogeneous. Standardised nation-wide notification for sGAS disease surveillance must be considered in combination with the development of a Communicable Diseases Network of Australia (CDNA) Series of National Guideline (SoNG), to accurately define and address disease burden across populations in Australia.

TRIAL REGISTRATION

This review is registered with PROSPERO. Registration number: CRD42019140440.

Positive oral health outcomes: A partnership model improves care in a rural Indigenous community

OBJECTIVE

The purpose of this study was to explore the benefits of a partnership between a university dental school and a Community Controlled Health Service, specifically in relation to improving the oral health of an underserved rural Indigenous community. We sought community opinions on health and social outcomes arising from the service provided by the dental student clinical outplacement.

SETTING

In Dalby, Queensland.

PARTICIPANTS

In total, 38 participants in five focus groups were representative of local Indigenous community Elders, community health support group members and management and staff.

DESIGN

A descriptive qualitative study employing semi-structured audio-recorded focus group discussions conducted with purposefully selected Indigenous community groups to explore participant views and experience of the partnership model. Qualitative data were analysed using thematic content analysis.

RESULTS

The Indigenous community representatives expressed positive benefit in both their general and oral health awareness, in improved access to dental care provided in their own safe space, while they were pleased to assist with students' learning. They viewed the partnership as mutually beneficial. Suggestions for enhancement of the oral health service were also offered.

CONCLUSION

This partnership between a university and a Community Controlled Health Service provides sustainable positive social and health benefits for the targeted Indigenous community and for the wider local population, while simultaneously providing enhanced educational benefits for students on clinical outplacement. Translation and uptake of this successful model of care would benefit both underserved communities and dental and other health care professional educators worldwide.

Standardization of Epidemiological Surveillance of Group A Streptococcal Impetigo

Impetigo is a highly contagious bacterial infection of the superficial layer of skin. Impetigo is caused by group A Streptococcus (Strep A) and Staphylococcus aureus, alone or in combination, with the former predominating in many tropical climates. Strep A impetigo occurs mainly in early childhood, and the burden varies worldwide. It is an acute, self-limited disease, but many children experience frequent recurrences that make it a chronic illness in some endemic settings. We present a standardized surveillance protocol including case definitions for impetigo including both active (purulent, crusted) and resolving (flat, dry) phases and discuss the current tests used to detect Strep A among persons with impetigo. Case classifications that can be applied are detailed, including differentiating between incident (new) and prevalent (existing) cases of Strep A impetigo. The type of surveillance methodology depends on the burden of impetigo in the community. Active surveillance and laboratory confirmation is the preferred method for case detection, particularly in endemic settings. Participant eligibility, surveillance population and additional considerations for surveillance of impetigo, including examination of lesions, use of photographs to document lesions, and staff training requirements (including cultural awareness), are addressed. Finally, the core elements of case report forms for impetigo are presented and guidance for recording the course and severity of impetigo provided.

Scabies incidence and association with skin and soft tissue infection in Loyalty Islands Province, New Caledonia: A 15-year retrospective observational study using electronic health records

Background

Scabies and its complications are a public health problem in the low- and middle-income countries of the Western Pacific region. However, no data are available for the relatively wealthy French territory of New Caledonia. This study aimed to determine the incidence of scabies and its association with skin and soft tissue infection (SSTI) in Loyalty Islands Province (LIP) (20,000 inhabitants), New Caledonia.

Methodology/Principal findings

This retrospective observational study reviewed cases of scabies and SSTI extracted from the electronic health record databases of LIP clinics for the period 2004–2018. Data were validated through double sampling. The overall scabies incidence rate (IR) and scabies IRs by sex and age group were calculated. Scabies seasonality was evaluated. For children <5 years, the presence of SSTI was compared between the 3-month period preceding scabies diagnosis/treatment and the 3-month period preceding the 1-year anniversary of scabies diagnosis/treatment (self-matching).

A total of 16,843 scabies cases were extracted using a detection algorithm with a sensitivity of 96.7% and a specificity of 99.9%. From 2004 to 2018, the average overall scabies IR was 5.9% and the average scabies IR in children <1 year was 18.4%. Almost two-thirds of children aged 14 years had a history of scabies. Females were more affected, especially in the 20–39 age group (sex ratio>2). A strong seasonality was observed, with a 30% increase in winter. In children <5 years, SSTIs were 4.3 times more frequent in the 3 months preceding the scabies diagnosis than in the 3 months preceding the 1-year anniversary of scabies treatment (p<0.001).

Conclusions

Although health care is much better in New Caledonia than in neighboring countries, scabies is highly endemic in LIP. The disease is especially common in children <2 years and is associated with many SSTIs in children <5 years. Mass drug administration should be considered.

Scabies is a known public health problem in the Pacific region. This study aimed to determine the importance of scabies and associated skin infections in the Loyalty Island Province (LIP) of New Caledonia (20,000 inhabitants).

The provincial electronic medical database was searched for all cases of scabies and skin infection that occurred in the LIP population between 2004 and 2018. To evaluate the impact of scabies on skin infections, we measured the decrease in the number of skin infections in children <5 years one year after scabies treatment.

Over the study period, the average number of scabies cases occurring each year was 6 per 100 inhabitants. In children <1 year, this number was 18 per 100 inhabitants. We found that 80% of children aged 15 years had experienced at least one episode of scabies. We also observed a fourfold decrease in the number of skin infections in children <5 years 1 year after treatment. Scabies was more frequent (+30%) in winter.

Ear microbiota and middle ear disease: a longitudinal pilot study of Aboriginal children in a remote south Australian setting

Background

Otitis media (OM) is a major disease burden in Australian Aboriginal children, contributing to serious long-term health outcomes. We report a pilot analysis of OM in children attending an outreach ear and hearing clinic in a remote south Australian community over a two-year period. Our study focuses on longitudinal relationships between ear canal microbiota characteristics with nasopharyngeal microbiota, and clinical and treatment variables.

Results

Middle ear health status were assessed in 19 children (aged 3 months to 8 years) presenting in remote western South Australia and medical interventions were recorded. Over the two-year study period, chronic suppurative OM was diagnosed at least once in 7 children (37%), acute OM with perforation in 4 children (21%), OM with effusion in 11 children (58%), while only 1 child had no ear disease. Microbiota analysis of 19 children (51 sets of left and right ear canal swabs and nasopharyngeal swabs) revealed a core group of bacterial taxa that included Corynebacterium, Alloiococcus, Staphylococcus, Haemophilus, Turicella, Streptococcus, and Pseudomonas. Within-subject microbiota similarity (between ears) was significantly greater than inter-subject similarity, regardless of differences in ear disease (p = 0.0006). Longitudinal analysis revealed changes in diagnosis to be associated with more pronounced changes in microbiota characteristics, irrespective of time interval. Ear microbiota characteristics differed significantly according to diagnosis (P (perm) = 0.0001). Diagnoses featuring inflammation with tympanic membrane perforation clustering separately to those in which the tympanic membrane was intact, and characterised by increased Proteobacteria, particularly Haemophilus influenzae, Moraxella catarrhalis, and Oligella. While nasopharyngeal microbiota differed significantly in composition to ear microbiota (P (perm) = 0.0001), inter-site similarity was significantly greater in subjects with perforated tympanic membranes, a relationship that was associated with the relative abundance of H. influenzae in ear samples (r_s = − 0.71, p = 0.0003). Longitudinal changes in ear microbiology reflected changes in clinical signs and treatment.

Conclusions

Children attending the ear and hearing clinic in a remote Aboriginal community present with a broad spectrum of OM conditions and severities, consistent with other remote Aboriginal communities. Ear microbiota characteristics align with OM diagnosis and change with disease course. Nasopharyngeal microbiota characteristics are consistent with the contribution of acute upper respiratory infection to OM aetiology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-022-02436-x.

Scabies in remote Aboriginal and Torres Strait Islander populations in Australia: A narrative review

Scabies has recently gained international attention, with the World Health Organization (WHO) recognizing it as a neglected tropical disease. The International Alliance for the Control of Scabies recently formed as a partnership of more than 15 different countries, with an aim to lead a consistent and collaborative approach to preventing and controlling scabies globally. Scabies is most prevalent in low-resource and low socioeconomic areas that experience overcrowding and has a particularly high prevalence in children, with an estimated 5% to 10% in endemic countries. Scabies is widespread in remote Aboriginal and Torres Strait Islander communities in Australia with the prevalence of scabies in Aboriginal and Torres Strait Islander children in remote communities estimated to be as high as 33%, making it the region with the third highest prevalence in the world. This population group also have very high rates of secondary complications of scabies such as impetigo, poststreptococcal glomerulonephritis (PSGN), and rheumatic heart disease (RHD). This article is a narrative review of scabies in remote Aboriginal and Torres Strait Islander populations in Australia, including clinical manifestations of disease and current treatment options and guidelines. We discuss traditional approaches to prevention and control as well as suggestions for future interventions including revising Australian treatment guidelines to widen the use of oral ivermectin in high-risk groups or as a first-line treatment.

Formative evaluation of a community-based approach to reduce the incidence of Strep A infections and acute rheumatic fever

OBJECTIVES

To explore the acceptability of a novel, outreached-based approach to improve primary and primordial prevention of Strep A skin sores, sore throats and acute rheumatic fever in remote Aboriginal communities.

METHODS

A comprehensive prevention program delivered by trained Aboriginal Community Workers was evaluated using approximately fortnightly household surveys about health and housing and clinical records.

RESULTS

Twenty-seven primary participants from three remote Aboriginal communities in the Northern Territory consented, providing 37.8 years of retrospective baseline data and 18.5 years of prospective data during the study period. Household members were considered to be secondary participants. Five Aboriginal Community Workers were trained and employed, delivering a range of supports to households affected by acute rheumatic fever including environmental health support and education. Clinical record audit and household self-report of Strep A infections were compared. No association between clinical- and self-report was identified.

CONCLUSIONS

Ongoing participation suggests this outreach-based prevention program was acceptable and associated with improved reporting of household maintenance issues and awareness of prevention opportunities for Strep A infections. Implications for public health: Biomedical, clinic-based approaches to the management of Strep A infections in remote communities can be usefully augmented by outreach-based supports delivered by Aboriginal Community Workers responding to community needs.

Housing conditions and health in Indigenous Australian communities: current status and recent trends

Ensuring sufficient and adequately maintained housing in Indigenous Australian communities remains an ongoing policy challenge for government, with major implications for the health of Indigenous Australians. This study sought to characterise the current status of housing conditions experienced by Indigenous Australians, with special reference to the Northern Territory. The assessment examined a range of indicators relating to crowding, dwelling condition, 'health hardware', and provision of maintenance and repairs. While acknowledging data deficiencies and inconsistencies, the analysis produced mixed results. There was evidence of a reduction in crowding but little observable improvement in the provision of maintenance and repairs. Some housing-related health outcomes have shown improvement, though these have tended to coincide with mass treatment campaigns. Achieving the goal of healthy homes - and ultimately closing the gap on Indigenous disadvantage - requires further investment in new houses that are appropriately designed and constructed, alongside an increased emphasis on cyclical maintenance.

Outbreak of multi-drug-resistant (MDR) Shigella flexneri in northern Australia due to an endemic regional clone acquiring an IncFII plasmid

Epidemiological surveillance of Shigella spp. in Australia is conducted to inform public health response. Multi-drug resistance has recently emerged as a contributing factor to sustained local transmission of Shigella spp. All data were collected as part of routine public health surveillance, and strains were whole-genome sequenced for further molecular characterisation. 108 patients with an endemic regional Shigella flexneri strain were identified between 2016 and 2019. The S. flexneri phylogroup 3 strain endemic to northern Australia acquired a multi-drug resistance conferring blaDHA plasmid, which has an IncFII plasmid backbone with virulence and resistance elements typically found in IncR plasmids. This is the first report of multi-drug resistance in Shigella sp. in Australia that is not associated with men who have sex with men. This strain caused an outbreak of multi-drug-resistant S. flexneri in northern Australia that disproportionality affects Aboriginal and Torres Strait Islander children. Community controlled public health action is recommended.

Rheumatic heart disease: A review of the current status of global research activity

Rheumatic heart disease (RHD) is a serious and long-term consequence of acute rheumatic fever (ARF), an autoimmune sequela of a mucosal infection by Streptococcus pyogenes (Group A Streptococcus, Strep A). The pathogenesis of ARF and RHD is complex and not fully understood but involves host and bacterial factors, molecular mimicry, and aberrant host innate and adaptive immune responses that result in loss of self-tolerance and subsequent cross-reactivity with host tissues. RHD is entirely preventable yet claims an estimated 320 000 lives annually. The major burden of disease is carried by developing nations and Indigenous populations within developed nations, including Australia. This review will focus on the epidemiology, pathogenesis and treatment of ARF and RHD in Australia, where: streptococcal pyoderma, rather than streptococcal pharyngitis, and Group C and Group G Streptococcus, have been implicated as antecedents to ARF; the rates of RHD in remote Indigenous communities are persistently among the highest in the world; government register-based programs coordinate disease screening and delivery of prophylaxis with variable success; and researchers are making significant progress in the development of a broad-spectrum vaccine against Strep A.

Health Disparities among Australia's Remote-Dwelling Aboriginal People: A Report from 2020

BACKGROUND

Australia has 2 distinct indigenous groups, Torres Strait Islanders and Aborigines. The Aborigines, described in this report, first colonized the continent 65 millennia ago. Those still living in the Northern Territory (NT) retain much ancestrally derived genetic complement but also are the most health-challenged by environment and lifestyle in 21st century. Reports providing overviews of these disparities are, as yet, rare.

CONTENT

This review defines the studied population and then describes and attempts to explain contemporary clinical findings among Australia's remote-dwelling Aborigines, principally in the NT. The report is structured by life stage and then by organ system. Finally, a brief synthesis is advanced concerning the disparities that Australia's Aboriginals face.

SUMMARY

In 2015-2017, NT aboriginal life expectancy for people then born was 66.6 years for men and 69.9 years for women compared with 78.1 and 82.7 years, respectively, among nonindigenous Territorians. Principal causes of the reduced longevity, with nonindigenous comparisons, include adolescent pregnancy, with maternal use of alcohol and tobacco (each 7-fold greater); fetal alcohol spectrum disorder and attention deficit hyperactivity disorder; skin infections, both scabies and impetigo (50-fold greater); rheumatic heart disease (260-fold greater); premature acute myocardial infarction (9-fold greater); bronchiectasis (40-fold greater); lung cancer (2-fold greater); diabetes mellitus (10-fold greater); renal failure (30-fold greater); and suicide (2-fold greater). Some disease has genetic roots, secondary to prolonged genetic drift. Much arises from avoidable stressors and from contemporary environmental disparities in housing. The Europid diet is also not helpful.

Estimation of the force of infection and infectious period of skin sores in remote Australian communities using interval-censored data

Prevalence of impetigo (skin sores) remains high in remote Australian Aboriginal communities, Fiji, and other areas of socio-economic disadvantage. Skin sore infections, driven primarily in these settings by Group A Streptococcus (GAS) contribute substantially to the disease burden in these areas. Despite this, estimates for the force of infection, infectious period and basic reproductive ratio-all necessary for the construction of dynamic transmission models-have not been obtained. By utilising three datasets each containing longitudinal infection information on individuals, we estimate each of these epidemiologically important parameters. With an eye to future study design, we also quantify the optimal sampling intervals for obtaining information about these parameters. We verify the estimation method through a simulation estimation study, and test each dataset to ensure suitability to the estimation method. We find that the force of infection differs by population prevalence, and the infectious period is estimated to be between 12 and 20 days. We also find that optimal sampling interval depends on setting, with an optimal sampling interval between 9 and 11 days in a high prevalence setting, and 21 and 27 days for a lower prevalence setting. These estimates unlock future model-based investigations on the transmission dynamics of skin sores.

High-quality nuclear genome for Sarcoptes scabiei-A critical resource for a neglected parasite

The parasitic mite Sarcoptes scabiei is an economically highly significant parasite of the skin of humans and animals worldwide. In humans, this mite causes a neglected tropical disease (NTD), called scabies. This disease results in major morbidity, disability, stigma and poverty globally and is often associated with secondary bacterial infections. Currently, anti-scabies treatments are not sufficiently effective, resistance to them is emerging and no vaccine is available. Here, we report the first high-quality genome and transcriptomic data for S. scabiei. The genome is 56.6 Mb in size, has a a repeat content of 10.6% and codes for 9,174 proteins. We explored key molecules involved in development, reproduction, host-parasite interactions, immunity and disease. The enhanced 'omic data sets for S. scabiei represent comprehensive and critical resources for genetic, functional genomic, metabolomic, phylogenetic, ecological and/or epidemiological investigations, and will underpin the design and development of new treatments, vaccines and/or diagnostic tests.

Dietary intake of Aboriginal Australian children aged 6-36 months in a remote community: a cross-sectional study

BACKGROUND

Scarce literature comprehensively captures the transition to solid foods for children in remote Aboriginal Australian communities, a population expected to be especially vulnerable to nutritional inadequacy for largely socio-economic reasons. This study describes the dietary intake of children aged 6-36 months in a remote Aboriginal community during the years of solids introduction and establishment. Specifically, we aimed to explore milk feeding practices, major sources of nutrition and traditional food consumption, dietary patterns and nutrient and food group intakes, and compare these to national and international recommendations.

METHODS

This dietary assessment was conducted as part of an observational, cross-sectional Child Health and Nutrition study. Three 24-h dietary recalls were completed with the parent/care-giver of each participant over 2-4 weeks, capturing a pay-week, non-pay-week and weekend day from October 2017-February 2018. Additional information collected included sociodemographic data, food security status, usual cooking practices, and attendance at playgroup.

RESULTS

Diet histories for 40 children were included in the analysis (~ 40% of the population). Breast feeding rates were high (85%), with mothers exclusively feeding on demand. Very few participants met recommended intakes for wholegrains (n = 4, 10%), vegetables (n = 7, 18%), dairy (n = 5, 18%) and fruit (n = 13, 33%), while more children met the guidelines for meat (n = 19, 48%) and discretionary food intake (n = 28, 70%). Traditional foods were always nutritionally dense and consumed frequently (n = 22, 55% of children). Statistically significant pay-cycle differences in intakes of all macro-, and numerous micro-nutrients were observed.

CONCLUSIONS

Many positive early feeding practices are currently enacted in remote Aboriginal communities including responsive and long duration breastfeeding, and nutrient-dense traditional food consumption from earliest solids introduction. However, the non-pay-week/pay-week cycle is impacting the quality and quantity of children's diets at a time of rapid growth and development.

Barriers and Enablers of Health Service Utilisation for Childhood Skin Infections in Remote Aboriginal Communities of Western Australia

In Australia, children living in remote Aboriginal communities experience high rates of skin infections and associated complications. Prompt presentation to primary care health services is crucial for early diagnosis and treatment. We performed a qualitative study in four remote Aboriginal communities in the Pilbara region of Western Australia to explore factors that affected health service utilisation for childhood skin infections in this setting. The study consisted of semistructured interviews and focus group discussions with parents and carers (n = 16), healthcare practitioners (n = 15) and other community service providers (n = 25). We used Andersen's health service utilisation model as an analytical framework. Our analysis captured a wide range of barriers that may undermine timely use of health services for childhood skin infections. These included general factors that illustrate the importance of cultural competency amongst healthcare providers, patient-centred care and community engagement. Relating specifically to health service utilisation for childhood skin infections, we identified their apparent normalisation and the common use of painful benzathine penicillin G injections for their treatment as important barriers. Health service utilisation in this setting may be enhanced by improving general awareness of the significance of childhood skin infections, actively engaging parents and carers in consultation and treatment processes and strengthening community involvement in health service activities.

Burden of skin disease in two remote primary healthcare centres in northern and central Australia

The burden of skin infections across all age groups in remote Australian Indigenous communities is currently unknown. In a retrospective audit of 439 residents from two remote communities presenting to health clinics, skin conditions were the most common reason for presentation (1603/7392, 22%) and 330/439 (75%) residents presented at least once with a skin infection. Skin infections are an under-appreciated and dominant reason for presentation to primary healthcare centres in these indigenous communities and public health campaigns to address this should incorporate all age groups.

Review of Aboriginal child health services in remote Western Australia identifies challenges and informs solutions

BACKGROUND

Despite a national focus on closing the gap between Aboriginal and non-Aboriginal child health outcomes in Australia, there remain significant challenges, including provision of health services in very remote communities. We aimed to identify and map child health services in the very remote Fitzroy Valley, West Kimberley, and document barriers to effective service delivery.

METHODS

Identification and review of all regional child health services and staffing in 2013. Verification of data by interview with senior managers and staff of key providers in the Western Australian Country Health Service, Kimberley Population Health Unit, Nindilingarri Cultural Health Services and non-government providers.

RESULTS

We identified no document providing a comprehensive overview of child health services in the Fitzroy Valley. There were inadequate numbers of health professionals, facilities and accommodation; high staff turnover; and limited capacity and experience of local health professionals. Funding and administrative arrangements were complex and services poorly coordinated and sometimes duplicated. The large geographic area, distances, extreme climate and lack of public and private transport challenge service delivery. The need to attend to acute illness acts to deprioritise crucial primary and preventative health care and capacity for dealing with chronic, complex disorders. Some services lack cultural safety and there is a critical shortage of Aboriginal Health Workers (AHW).

CONCLUSIONS

Services are fragmented and variable and would benefit from a coordinated approach between government, community-controlled agencies, health and education sectors. A unifying model of care with emphasis on capacity-building in Aboriginal community members and training and support for AHW and other health professionals is required but must be developed in consultation with communities. Innovative diagnostic and care models are needed to address these challenges, which are applicable to many remote Australian settings outside the Fitzroy Valley, as well as other countries globally. Our results will inform future health service planning and strategies to attract and retain health professionals to work in these demanding settings. A prospective audit of child health services is now needed to inform improved planning of child health services with a focus on identifying service gaps and training needs and better coordinating existing services to improve efficiency and potentially also efficacy.

Skin infections in Australian Aboriginal children: a narrative review

Impetigo, scabies, cellulitis and abscesses are common in Australian Aboriginal children. These conditions adversely affect wellbeing and are associated with serious long term sequelae, including invasive infection and post‐infectious complications, such as acute post‐streptococcal glomerulonephritis and acute rheumatic fever, which occurs at the highest documented rates in the world in remote Aboriginal communities.

Observational research in remote communities in northern Australia has demonstrated a high concurrent burden of scabies and impetigo and their post‐infectious complications.

Few data are available for other Australian states, especially for urban Aboriginal children; however, nationwide hospital data indicate that the disparity between Aboriginal and non‐Aboriginal children in skin infection prevalence also exists in urban settings.

The Australian National Healthy Skin Guideline summarises evidence‐based treatment of impetigo, scabies and fungal infections in high burden settings such as remote Aboriginal communities. It recommends systemic antibiotics for children with impetigo, and either topical permethrin or oral ivermectin (second line) for the individual and their contacts as equally efficacious treatments for scabies. β‐Lactams are the treatment of choice and trimethoprim–sulfamethoxazole and clindamycin are effective alternatives for treatment of paediatric cellulitis. Abscesses require incision and drainage and a 5‐day course of trimethoprim–sulfamethoxazole or clindamycin.

Addressing normalisation of skin infections and the social determinants of skin health are key challenges for the clinician. Research is underway on community‐wide skin health programs and the role for mass drug administration which will guide future management of these common, treatable diseases.

High-throughput metagenome analysis of the Sarcoptes scabiei internal microbiota and in-situ identification of intestinal Streptomyces sp

Multiple parasitic arthropods of medical importance depend on symbiotic bacteria. While the link between scabies and secondary bacterial infections causing post infective complications of Group A streptococcal and staphylococcal pyoderma is increasingly recognized, very little is known about the microbiota of Sarcoptes scabiei. Here we analyze adult female mite and egg metagenome datasets. The majority of adult mite bacterial reads matched with Enterobacteriaceae (phylum Proteobacteria), followed by Corynebacteriaceae (phylum Actinobacteria). Klebsiella was the most dominant genus (78%) and Corynebacterium constituted 9% of the assigned sequences. Scabies mite eggs had a more diverse microbial composition with sequences from Proteobacteria being the most dominant (75%), while Actinobacteria, Bacteroidetes and Firmicutes accounted for 23% of the egg microbiome sequences. DNA sequences of a potential endosymbiont, namely Streptomyces, were identified in the metagenome sequence data of both life stages. The presence of Streptomyces was confirmed by conventional PCR. Digital droplet PCR indicated higher Streptomyces numbers in adult mites compared to eggs. Streptomyces were localized histologically in the scabies mite gut and faecal pellets by Fluorescent In Situ Hybridization (FISH). Streptomyces may have essential symbiotic roles in the scabies parasite intestinal system requiring further investigation.

The public health control of scabies: priorities for research and action

Scabies is a parasitic disease of the skin that disproportionately affects disadvantaged populations. The disease causes considerable morbidity and leads to severe bacterial infection and immune-mediated disease. Scientific advances from the past 5 years suggest that scabies is amenable to population-level control, particularly through mass drug administration. In recognition of these issues, WHO added scabies to the list of neglected tropical diseases in 2017. To develop a global control programme, key operational research questions must now be addressed. Standardised approaches to diagnosis and methods for mapping are required to further understand the burden of disease. The safety of treatments for young children, including with ivermectin and moxidectin, should be investigated. Studies are needed to inform optimum implementation of mass treatment, including the threshold for intervention, target, dosing, and frequency. Frameworks for surveillance, monitoring, and evaluation of control strategies are also necessary.

High burden of infectious disease and antibiotic use in early life in Australian Aboriginal communities

OBJECTIVE

To quantify the childhood infectious disease burden and antibiotic use in the Northern Territory's East Arnhem region through synthesis and analysis of historical data resources.

METHODS

We combined primary health clinic data originally reported in three separate publications stemming from the East Arnhem Healthy Skin Project (Jan-01 to Sep-07). Common statistical techniques were used to explore the prevalence of infectious conditions and the seasonality of infections, and to measure rates of antibiotic use.

RESULTS

There was a high monthly prevalence of respiratory (mean: 32% [95% confidence interval (CI): 20%, 34%]) and skin (mean: 20% [95%CI: 19%, 22%]) infectious syndromes, with upper respiratory tract infections (mean: 29% [95%CI: 27%, 31%]) and skin sores (mean: 15% [95%CI: 14%, 17%]) the most common conditions. Antibiotics were frequently prescribed with 95% (95%CI: 91%, 97%) of children having received at least one antibiotic prescription by their first birthday, and 47% having received six antibiotic prescriptions; skin sores being a key driver.

CONCLUSIONS

Early life infections drive high antibiotic prescribing rates in remote Aboriginal communities. Implications for public health: Eliminating skin disease could reduce antibiotic use by almost 20% in children under five years of age in this population.

The Relationship between Infectious Diseases and Housing Maintenance in Indigenous Australian Households

This research aimed to identify systemic housing-level contributions to infectious disease transmission for Indigenous Australians, in response to the Government program to ‘close the gap’ of health and other inequalities. A narrative literature review was performed in accordance to PRISMA guidelines. The findings revealed a lack of housing maintenance was associated with gastrointestinal infections, and skin-related diseases were associated with crowding. Diarrhoea was associated with the state of food preparation and storage areas, and viral conditions such as influenza were associated with crowding. Gastrointestinal, skin, ear, eye, and respiratory illnesses are related in various ways to health hardware functionality, removal and treatment of sewage, crowding, presence of pests and vermin, and the growth of mould and mildew. The research concluded that infectious disease transmission can be reduced by improving housing conditions, including adequate and timely housing repair and maintenance, and the enabling environment to perform healthy behaviours.

Temporal trends in paediatric bacterial meningitis in a tropical Australian region: 1992-2014

AIM

The epidemiology of community-acquired bacterial meningitis has changed following the introduction of routine immunisation against common causative organisms. Indigenous children living in the Northern Territory, Australia, have high rates of bacterial infections. This study describes changes in the epidemiology of childhood bacterial meningitis and the distribution of the burden of disease in the Top End.

METHODS

A retrospective review of cases derived from hospital medical records and laboratory data was performed. Inclusion criteria were children aged 3 months to 14 years of age, admitted to Royal Darwin Hospital between 1992 and 2014 and diagnosed with bacterial meningitis. Annual incidence of bacterial meningitis and the distribution of causative pathogens are described. Demographic data, investigations, treatment and outcomes were compared between Indigenous and non-Indigenous children.

RESULTS

There were 137 cases of childhood bacterial meningitis identified over the 23-year period. The incidence reduced from 21 per 100 000 children per year for 1992-2002 to 11 per 100 000 per year for 2003-2014 (P = 0.0025). Haemophilus influenzae type b, Streptococcus pneumoniae and Neisseria meningitidis were the most common causative organisms, with a reduction in cases for each pathogen observed across the study period. Indigenous children were over-represented (104/137, 76%). Case fatality rate was 8% (11/137); 91% of fatal cases presented to a remote facility.

CONCLUSIONS

The incidence of childhood bacterial meningitis has declined in the Northern Territory of Australia, but Indigenous children are disproportionately affected. Routine immunisation is beneficial for all, although further efforts to 'Close the Gap' between health outcomes in Indigenous and non-Indigenous Australians is required.

Ascertaining infectious disease burden through primary care clinic attendance among young Aboriginal children living in four remote communities in Western Australia

Infectious diseases contribute a substantial burden of ill-health in Australia’s Aboriginal children. Skin infections have been shown to be common in remote Aboriginal communities, particularly in the Northern Territory, Australia. However, primary care data on skin and other infectious diseases among Aboriginal children living in remote areas of Western Australia are limited. We conducted a retrospective review of clinic presentations of all children aged 0 to 5 years presenting to four clinics located in the Western Desert region of Western Australia between 2007 and 2012 to determine this burden at a local level. Infectious diseases accounted for almost 50% of all clinic presentations. Skin infections (sores, scabies and fungal infections) were the largest proportion (16%), with ear infections (15%) and upper respiratory infections (13%) also high. Skin infections remained high in all age groups; 72% of children presented at least once with skin infections. Scabies accounted for only 2% of all presentations, although one-quarter of children presented during the study for management of scabies. Skin sores accounted for 75% of the overall burden of skin infections. Improved public health measures targeting bacterial skin infections are needed to reduce this high burden of skin infections in Western Australia.

The Skin-A Common Pathway for Integrating Diagnosis and Management of NTDs

Many of the neglected tropical diseases (NTDs) have major skin manifestations. These skin-related NTDs or ‘skin NTDs’ cause significant morbidity and economic hardship in some of the poorest communities worldwide. We draw attention to the collective burden of skin disease and suggest that the skin be used as a platform for the integration of control activities for NTDs. The opportunities for integration are numerous, ranging from diagnosis and disease mapping to mass drug administration and morbidity management. The dermatology community has an important role to play, and will be expected to support research and control activities globally.

Scabies and risk of skin sores in remote Australian Aboriginal communities: A self-controlled case series study

Background

Skin sores caused by Group A streptococcus (GAS) infection are a major public health problem in remote Aboriginal communities. Skin sores are often associated with scabies, which is evident in scabies intervention programs where a significant reduction of skin sores is seen after focusing solely on scabies control. Our study quantifies the strength of association between skin sores and scabies among Aboriginal children from the East Arnhem region in the Northern Territory.

Methods and results

Pre-existing datasets from three published studies, which were conducted as part of the East Arnhem Healthy Skin Project (EAHSP), were analysed. Aboriginal children were followed from birth up to 4.5 years of age. Self-controlled case series design was used to determine the risks, within individuals, of developing skin sores when infected with scabies versus when there was no scabies infection. Participants were 11.9 times more likely to develop skin sores when infected with scabies compared with times when no scabies infection was evident (Incidence Rate Ratio (IRR) 11.9; 95% CI 10.3–13.7; p<0.001), and this was similar across the five Aboriginal communities. Children had lower risk of developing skin sores at age ≤1 year compared to at age >1 year (IRR 0.8; 95% CI 0.7–0.9).

Conclusion

The association between scabies and skin sores is highly significant and indicates a causal relationship. The public health importance of scabies in northern Australia is underappreciated and a concerted approach is required to recognise and eliminate scabies as an important precursor of skin sores.

Skin sores, also known as impetigo, are highly contagious bacterial skin infections, which are found commonly in school children and occasionally in adults. Skin sores are prevalent in disadvantaged or resource-poor settings. In Australia, about two thirds of Aboriginal children suffer from skin sores by their first birthday. If untreated or treated poorly, skin sores can eventually cause heart and kidney problems. It is also believed that scabies, another common skin infection in Aboriginal children, can increase the risk of developing skin sores by allowing the bacteria to enter the skin more easily through breaks in the skin. Our research explored the following: if scabies is a risk factor for skin sores then what is the strength of the association between the two conditions.

Factors that impact access to ongoing health care for First Nation children with a chronic condition

BACKGROUND

Access to multidisciplinary health care services for First Nation children with a chronic condition is critical for the child's health and well-being, but disparities and inequality in health care systems have been almost impossible to eradicate for First Nation people globally. The objective of this review is to identify the factors that impact access and ongoing care for First Nation children globally with a chronic condition.

METHODS

An extensive systematic search was conducted of nine electronic databases to identify primary studies that explored factors affecting access to ongoing services for First Nation children with a chronic disease or injury. Due to the heterogeneity of included studies the Mixed Method Appraisal Tool (MMAT) was used to assess study quality.

RESULTS

A total of six studies from Australia, New Zealand and Canada were identified and included in this review. Four studies applied qualitative approaches using in-depth semi structured interviews, focus groups and community fora. Two of the six studies used quantitative approaches. Facilitators included the utilisation of First Nation liaison workers or First Nation Health workers. Key barriers that emerged included lack of culturally appropriate health care, distance, language and cultural barriers, racism, the lack of incorporation of First Nation workers in services, financial difficulties and transport issues.

CONCLUSION

There are few studies that have identified positive factors that facilitate access to health care for First Nation children. There is an urgent need to develop programs and processes to facilitate access to appropriate health care that are inclusive of the cultural needs of First Nation children.

Health service utilisation amongst urban Aboriginal and Torres Strait Islander children aged younger than 5 years registered with a primary health-care service in South-East Queensland

AIM

The majority of Australia's Aboriginal and/or Torres Strait Islander children live in urban areas; however, little is known about their health service use. We aimed to describe health service utilisation amongst a cohort of urban Aboriginal and/or Torres Strait Islander children aged <5 years.

METHODS

We analysed health service utilisation data collected in an ongoing prospective cohort study of children aged <5 years registered with an Aboriginal-owned and operated primary health-care service. Enrolled children were followed monthly for 12 months, with data on health service utilisation collected at baseline and at each monthly follow-up. Health service utilisation rates, overall and by service provider and reason for presentation, were calculated and reported as incidence rates per 100 child-months with the corresponding 95% confidence intervals (CIs).

RESULTS

Between February 2013 and November 2015, 180 children were enrolled, and 1541 child-months of observation were available for analysis. The overall incidence of health service utilisation was 52.5 per 100 child-months (95% CI 48.7-56.5); 81% of encounters were with general practitioners. Presentation rates were the highest for acute respiratory illnesses (30.7/100 child-months, 95% CI 27.8-33.9).

CONCLUSIONS

In this community, acute respiratory illnesses are predominant causes of health service utilisation in young children. The health-care utilisation profile of these children presents important opportunities for health promotion and intervention.

Calculation of the age of the first infection for skin sores and scabies in five remote communities in northern Australia

Prevalence of skin sores and scabies in remote Australian Aboriginal communities remains unacceptably high, with Group A Streptococcus (GAS) the dominant pathogen. We aim to better understand the drivers of GAS transmission using mathematical models. To estimate the force of infection, we quantified the age of first skin sores and scabies infection by pooling historical data from three studies conducted across five remote Aboriginal communities for children born between 2001 and 2005. We estimated the age of the first infection using the Kaplan-Meier estimator; parametric exponential mixture model; and Cox proportional hazards. For skin sores, the mean age of the first infection was approximately 10 months and the median was 7 months, with some heterogeneity in median observed by the community. For scabies, the mean age of the first infection was approximately 9 months and the median was 8 months, with significant heterogeneity by the community and an enhanced risk for children born between October and December. The young age of the first infection with skin sores and scabies reflects the high disease burden in these communities.

Scabies, crusted (Norwegian) scabies and the diagnosis of mite sensitisation

Scabies is observed with relatively high frequency in Allergy and Dermatology clinics in developing countries where poor sanitary conditions are prevalent and increasingly in some areas of the world with increased immigrant populations. Since the immunological response to scabies mites includes the production of IgE class antibodies to Sarcoptes scabiei allergens which cross-react with Dermatophagoides major allergens Der p 1 and Der p 2, positive immediate-type skin tests to house dust mite extracts should be interpreted cautiously. Additionally, scabies should be included routinely in the differential diagnosis of itchy rashes in patients living in those areas.

The Cost of Acute Respiratory Infections With Cough Among Urban Aboriginal and Torres Strait Islander Children

Introduction: Acute respiratory infections with cough (ARIwC) contribute considerably to childhood morbidity, yet few studies have examined the cost of these illnesses among Australian children. Moreover, of the few studies that have, none are inclusive of Aboriginal and/or Torres Strait Islander children, despite this population experiencing a greater burden of respiratory illnesses. This study aimed to determine the costs of ARIwC among urban Aboriginal and/or Torres Strait Islander children from the perspective of caretakers, the public healthcare system, and employers. Methods: This cost of illness study used data collected from Aboriginal and/or Torres Strait Islander children aged <5 years enrolled in a 12 month prospective cohort study conducted through an urban primary healthcare clinic in Queensland, Australia. Illness-related resource use was collected for each episode of ARIwC reported, and costed at market rates. Linear regression was used to (a) examine cost per episode by season of illness onset and cough duration and (b) examine cost per month of observation by baseline child and family characteristics. Results: During the study period, a total of 264 episodes of ARIwC were reported among 138 children. The total mean cost was estimated to be $AU252 per non-hospitalized episode (95%CI 169-334). Caretakers, the public healthcare system and employers incurred 44, 39, and 17% of costs per episode, respectively. After accounting for months of completed follow-ups, the total mean cost per child per year was estimated to be $991 (95%CI 514-1468). Winter episodes and episodes resulting in chronic cough were associated with significantly higher costs per episode. A prior history of wheezing, connections to traditional lands and parent/guardian belief that antibiotics should be given until symptoms resolved were associated with significantly higher cost per child month of observation. Conclusion: The cost of ARIwC in this predominantly disadvantaged population is substantial, particularly for caretakers and this needs to be considered in both clinical management and public health initiatives. The importance of cultural factors on health and burden of illness should not be overlooked. Further research into the prevention of chronic cough may play an important role in reducing the economic burden of pediatric respiratory infections.

Hospital admissions for skin infections among Western Australian children and adolescents from 1996 to 2012

The objective of this study was to describe the occurrence of skin infection associated hospitalizations in children born in Western Australia (WA). We conducted a retrospective cohort study of all children born in WA between 1996 and 2012 (n = 469,589). Of these, 31,348 (6.7%) were Aboriginal and 240,237 (51.2%) were boys. We report the annual age-specific hospital admission rates by geographical location and diagnostic category. We applied log-linear regression modelling to analyse changes in temporal trends of hospitalizations. Hospitalization rates for skin infections in Aboriginal children (31.7/1000 child-years; 95% confidence interval [CI] 31.0–32.4) were 15.0 times higher (95% CI 14.5–15.5; P<0.001) than those of non-Aboriginal children (2.1/1000 child-years; 95% CI 2.0–2.1). Most admissions in Aboriginal children were due to abscess, cellulitis and scabies (84.3%), while impetigo and pyoderma were the predominant causes in non-Aboriginal children (97.7%). Admissions declined with age, with the highest rates for all skin infections observed in infants. Admissions increased with remoteness. Multiple admissions were more common in Aboriginal children. Excess admissions in Aboriginal children were observed during the wet season in the Kimberley and during summer in metropolitan areas. Our study findings show that skin infections are a significant cause of severe disease, requiring hospitalization in Western Australian children, with Aboriginal children at a particularly high risk. Improved community-level prevention of skin infections and the provision of effective primary care are crucial in reducing the burden of skin infection associated hospitalizations. The contribution of sociodemographic and environmental risk factors warrant further investigation.

Pediatric hospital admissions in Indigenous children: a population-based study in remote Australia

BACKGROUND

We analysed hospital admissions of a predominantly Aboriginal cohort of children in the remote Fitzroy Valley in Western Australia during the first 7 years of life.

METHODS

All children born between January 1, 2002 and December 31, 2003 and living in the Fitzroy Valley in 2009-2010 were eligible to participate in the Lililwan Project. Of 134 eligible children, 127 (95%) completed Stage 1 (interviews of caregivers and medical record review) in 2011 and comprised our cohort. Lifetime (0-7 years) hospital admission data were available and included the dates, and reasons for admission, and comorbidities. Conditions were coded using ICD-10-AM discharge codes.

RESULTS

Of the 127 children, 95.3% were Indigenous and 52.8% male. There were 314 admissions for 424 conditions in 89 (70.0%) of 127 children. The 89 children admitted had a median of five admissions (range 1-12). Hospitalization rates were similar for both genders (p = 0.4). Of the admissions, 108 (38.6%) were for 56 infants aged <12 months (median = 2.5, range = 1-8). Twelve of these admissions were in neonates (aged 0-28 days). Primary reasons for admission (0-7 years) were infections of the lower respiratory tract (27.4%), gastrointestinal system (22.7%), and upper respiratory tract (11.4%), injury (7.0%), and failure to thrive (5.4%). Comorbidities, particularly upper respiratory tract infections (18.1%), failure to thrive (13.6%), and anaemia (12.7%), were common. In infancy, primary cause for admission were infections of the lower respiratory tract (40.8%), gastrointestinal (25.9%) and upper respiratory tract (9.3%). Comorbidities included upper respiratory tract infections (33.3%), failure to thrive (18.5%) and anaemia (18.5%).

CONCLUSION

In the Fitzroy Valley 70.0% of children were hospitalised at least once before age 7 years and over one third of admissions were in infants. Infections were the most common reason for admission in all age groups but comorbidities were common and may contribute to need for admission. Many hospitalizations were feasibly preventable. High admission rates reflect disadvantage, remote location and limited access to primary healthcare and outpatient services. Ongoing public health prevention initiatives including breast feeding, vaccination, healthy diet, hygiene and housing improvements are crucial, as is training of Aboriginal Health Workers to increase services in remote communities.

Communicating the promise, risks, and ethics of large-scale, open space microbiome and metagenome research

The public commonly associates microorganisms with pathogens. This suspicion of microorganisms is understandable, as historically microorganisms have killed more humans than any other agent while remaining largely unknown until the late seventeenth century with the works of van Leeuwenhoek and Kircher. Despite our improved understanding regarding microorganisms, the general public are apt to think of diseases rather than of the majority of harmless or beneficial species that inhabit our bodies and the built and natural environment. As long as microbiome research was confined to labs, the public's exposure to microbiology was limited. The recent launch of global microbiome surveys, such as the Earth Microbiome Project and MetaSUB (Metagenomics and Metadesign of Subways and Urban Biomes) project, has raised ethical, financial, feasibility, and sustainability concerns as to the public's level of understanding and potential reaction to the findings, which, done improperly, risk negative implications for ongoing and future investigations, but done correctly, can facilitate a new vision of "smart cities." To facilitate improved future research, we describe here the major concerns that our discussions with ethics committees, community leaders, and government officials have raised, and we expound on how to address them. We further discuss ethical considerations of microbiome surveys and provide practical recommendations for public engagement.

Upper airway viruses and bacteria in urban Aboriginal and Torres Strait Islander children in Brisbane, Australia: a cross-sectional study

BACKGROUND

Respiratory morbidity in Australian Indigenous children is higher than their non-Indigenous counterparts, irrespective of urban or remote residence. There are limited studies addressing acute respiratory illness (ARI) in urban Indigenous children, particularly those that address the upper airway microbiome and its relationship to disease. We aimed to describe the prevalence of upper airway viruses and bacteria in symptomatic and asymptomatic urban-based Australian Indigenous children aged less than 5 years.

METHODS

A cross-sectional analysis of data collected at baseline in an ongoing prospective cohort study of urban Aboriginal and Torres Strait Islander children registered with a primary health care service in the northern suburbs of Brisbane, Australia. Clinical, demographic and epidemiological data and bilateral anterior nasal swabs were collected on enrolment. Polymerase chain reaction was performed on nasal swabs to detect 17 respiratory viruses and 7 bacteria. The primary outcome was the prevalence of these microbes at enrolment. Logistic regression was performed to investigate differences in microbe prevalence between children with and without acute respiratory illness with cough as a symptom (ARIwC) at time of specimen collection.

RESULTS

Between February 2013 and October 2015, 164 children were enrolled. The median age at enrolment was 18.0 months (IQR 7.2-34.3), 49.4% were boys and 56 children (34.2%) had ARIwC. Overall, 133/164 (81%) nasal swabs were positive for at least one organism; 131 (79.9%) for any bacteria, 59 (36.2%) for any virus and 57 (34.8%) for both viruses and bacteria. Co-detection of viruses and bacteria was more common in females than males (61.4% vs 38.6%, p = 0.044). No microbes, alone or in combination, were significantly associated with the presence of ARIwC.

CONCLUSIONS

The prevalence of upper airways microbes in asymptomatic children is similar to non-Indigenous children with ARIwC from the same region. Determining the aetiology of ARIwC in this community is complicated by the high prevalence of multiple respiratory pathogens in the upper airways.

STUDY REGISTRATION

Australia New Zealand Clinical Trial Registry Registration Number: 12,614,001,214,628. Retrospectively registered.

Complement inhibition by Sarcoptes scabiei protects Streptococcus pyogenes - An in vitro study to unravel the molecular mechanisms behind the poorly understood predilection of S. pyogenes to infect mite-induced skin lesions

Background

On a global scale scabies is one of the most common dermatological conditions, imposing a considerable economic burden on individuals, communities and health systems. There is substantial epidemiological evidence that in tropical regions scabies is often causing pyoderma and subsequently serious illness due to invasion by opportunistic bacteria. The health burden due to complicated scabies causing cellulitis, bacteraemia and sepsis, heart and kidney diseases in resource-poor communities is extreme. Co-infections of group A streptococcus (GAS) and scabies mites is a common phenomenon in the tropics. Both pathogens produce multiple complement inhibitors to overcome the host innate defence. We investigated the relative role of classical (CP), lectin (LP) and alternative pathways (AP) towards a pyodermic GAS isolate 88/30 in the presence of a scabies mite complement inhibitor, SMSB4.

Methodology/Principal findings

Opsonophagocytosis assays in fresh blood showed baseline immunity towards GAS. The role of innate immunity was investigated by deposition of the first complement components of each pathway, specifically C1q, FB and MBL from normal human serum on GAS. C1q deposition was the highest followed by FB deposition while MBL deposition was undetectable, suggesting that CP and AP may be mainly activated by GAS. We confirmed this result using sera depleted of either C1q or FB, and serum deficient in MBL. Recombinant SMSB4 was produced and purified from Pichia pastoris. SMSB4 reduced the baseline immunity against GAS by decreasing the formation of CP- and AP-C3 convertases, subsequently affecting opsonisation and the release of anaphylatoxin.

Conclusions/Significance

Our results indicate that the complement-inhibitory function of SMSB4 promotes the survival of GAS in vitro and inferably in the microenvironment of the mite-infested skin. Understanding the tripartite interactions between host, parasite and microbial pathogens at a molecular level may serve as a basis to develop improved intervention strategies targeting scabies and associated bacterial infections.

The molecular mechanisms that underpin the link between scabies and bacterial pathogens were unknown. We proposed that scabies mites play a role in the establishment, proliferation and transmission of opportunistic pathogens. We investigated here the synergy between mites and one of the most recognised mite associated pathogens, Streptococcus pyogenes. As part of the innate immune response mammals have a pre-programmed ability to recognise and immediately act against substances derived from fungal and bacterial microorganisms. This is mediated through a sequential biochemical cascade involving over 30 different proteins (complement system) which as a result of signal amplification triggers a rapid killing response. The complement cascade produces peptides that attract immune cells, increases vascular permeability, coats (opsonises) the surfaces of a pathogen, marking it for destruction, and directly disrupts foreign plasma membranes. To prevent complement mediated damage of their gut cells, scabies mites secrete several classes of complement inhibiting proteins into the mite gut and excrete them into the epidermal mite burrows. Furthermore, these inhibitors also provide protection for S. pyogenes. We verified here specifically the impact of the mite complement inhibitor SMSB4, to identify the molecular mechanisms behind the long recognised tendency of S. pyogenes to infect mite-induced skin lesions.

The Incidence and Short-term Outcomes of Acute Respiratory Illness with Cough in Children from a Socioeconomically Disadvantaged Urban Community in Australia: A Community-Based Prospective Cohort Study

BACKGROUND

Acute respiratory illnesses with cough (ARIwC) are predominant causes of morbidity in Australian Indigenous children; however, data on disease burden in urban communities are scarce. This study aimed to determine the incidence of ARIwC, the predictors of recurrent (≥4 episodes) ARIwC, and development of chronic cough following an ARIwC in urban, predominantly Indigenous, children aged <5 years from northern Brisbane, Australia.

METHODS

Prospective cohort study of children aged <5 years registered with a primary healthcare center. ARIwC episodes and outcomes were collected for 12 months. Recurrent ARIwC was defined as ≥4 episodes in 12 months. Chronic cough was defined as cough lasting >4 weeks. Children who developed chronic cough were reviewed by a pediatric pulmonologist. Incidence densities per child-month of observation were calculated and predictors of recurrent ARIwC and chronic cough were evaluated in logistic regression models.

RESULTS

Between February 2013 and November 2015, 200 children were enrolled; median age of 18.1 months, range (0.7-59.7 months) and 90% identified as Indigenous. A total of 1,722 child-months of observation were analyzed (mean/child = 8.58, 95% CI 8.18-9.0). The incidence of ARIwC was 24.8/100 child-months at risk (95% CI 22.3-27.5). Twenty-one children (10.5%) experienced recurrent ARIwC. Chronic cough was identified in 70/272 (25.7%) episodes of ARIwC. Predictors of recurrent ARIwC were presence of eczema, mold in the house, parent/carer employment status, and having an Aboriginal and Torres Strait Islander mother/non-Aboriginal and Torres Strait Islander father (compared to both parents being Aboriginal and Torres Strait Islander). Predictors of chronic cough included being aged <12 months, eczema, childcare attendance, previous history of cough of >4 weeks duration, having an Aboriginal and Torres Strait Islander mother/non-Aboriginal and Torres Strait Islander father (compared to both parents being Aboriginal and Torres Strait Islander), and a low income. Of those with chronic cough reviewed by a pediatric pulmonologist, a significant underlying disorder was found in 14 children (obstructive sleep apnea = 1, bronchiectasis = 2, pneumonia = 2, asthma = 3, tracheomalacia = 6).

DISCUSSION

This community of predominantly Aboriginal and Torres Strait Islander and socially disadvantaged children bear a considerable burden of ARIwC. One in 10 children will experience more than three episodes over a 12-month period and 1 in five children will develop chronic cough post ARIwC, some with a serious underlying disorder. Further larger studies that include a broader population base are needed.

Protocol for the systematic review of the prevention, treatment and public health management of impetigo, scabies and fungal skin infections in resource-limited settings

BACKGROUND

Impetigo, scabies, and fungal skin infections disproportionately affect populations in resource-limited settings. Evidence for standard treatment of skin infections predominantly stem from hospital-based studies in high-income countries. The evidence for treatment in resource-limited settings is less clear, as studies in these populations may lack randomisation and control groups for cultural, ethical or economic reasons. Likewise, a synthesis of the evidence for public health control within endemic populations is also lacking. We propose a systematic review of the evidence for the prevention, treatment and public health management of skin infections in resource-limited settings, to inform the development of guidelines for the standardised and streamlined clinical and public health management of skin infections in endemic populations.

METHODS

The protocol has been designed in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols statement. All trial designs and analytical observational study designs will be eligible for inclusion. A systematic search of the peer-reviewed literature will include PubMed, Excertpa Medica and Global Health. Grey literature databases will also be systematically searched, and clinical trials registries scanned for future relevant studies. The primary outcome of interest will be the clinical cure or decrease in prevalence of impetigo, scabies, crusted scabies, tinea capitis, tinea corporis or tinea unguium. Two independent reviewers will perform eligibility assessment and data extraction using standardised electronic forms. Risk of bias assessment will be undertaken by two independent reviewers according to the Cochrane Risk of Bias tool. Data will be tabulated and narratively synthesised. We expect there will be insufficient data to conduct meta-analysis. The final body of evidence will be reported against the Grades of Recommendation, Assessment, Development and Evaluation grading system.

DISCUSSION

The evidence derived from the systematic review will be used to inform the development of guidelines for the management of skin infections in resource-limited settings. The evidence derived will be intended for use by clinicians, public health practitioners and policy makers in the treatment of skin infections and the development of skin infection control programmes. The review will identify any gaps in the current evidence to provide direction for future research.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015029453.

Opportunities for Integrated Control of Neglected Tropical Diseases That Affect the Skin

Many neglected tropical diseases (NTDs) affect the skin, causing considerable disability, stigma, and exacerbation of poverty. However, there has been relatively little investment into laboratory research, epidemiology, diagnostic tools or management strategies to control tropical skin disease. Integration may advance the control of skin disease across a range of domains, including mapping, diagnosis, clinical management, and community control measures such as mass drug administration. Examples of successful integration strategies include programs targeting scabies, impetigo, yaws, and diseases causing lymphoedema. Future strategies should build on these experiences and the experience of integration of other NTDs, strengthen existing health systems, and contribute toward the attainment of Universal Health Coverage. Strong partnerships and political support and will be necessary to achieve these goals.

High absolute risk of severe infections among Indigenous adults in rural northern Australia is amplified by diabetes - A 7 year follow up study

AIMS

To quantify the risk of hospitalization for infections in Indigenous Australian adults with diabetes in rural and remote communities.

METHODS

2787 Indigenous adults including 396 with diabetes at baseline from 19 communities in North Queensland from 1998 to 2007 were included in the study. Main measures were weight, height, waist circumference, blood pressure, fasting glucose, lipids, self-reported tobacco smoking, alcohol intake and physical activity. Baseline data were linked to hospital separation data using probabilistic linkage. The association between diabetes and hospitalization for all causes and infections was investigated using generalized linear model (GLM) and adjusted for other baseline measurements.

RESULTS

During a median follow up of 7years, 461 participants were hospitalized with 762 episodes of infection. 277 patients with diabetes (70%) were hospitalized at least once. 40% (110 in 277) were for community acquired infections. Patients with diabetes were twice as likely to be hospitalized for infections as those without diabetes (adjusted risk ratio 2.1, 95% CI 1.6-2.8), especially for urinary tract infections, cellulitis, and septicaemia. Median length of stay was 6 (IQR 3-13) days for diabetes patients compared to 3.4days (IQR 2-6.4) for those without diabetes (P<0.001) CONCLUSIONS: In addition to an already high rate of hospitalizations for infections among Indigenous compared to non-Indigenous Australians, diabetes confers an additional risk for severe infections especially urinary tract infection, cellulitis and septicaemia. Recovery is also comparatively slower. Early recognition and management of these infections in the primary care setting may reduce this risk and better control of glycaemia and its risk factors may improve underlying immune dysfunction.

The Importance of Scabies Coinfection in the Treatment Considerations for Impetigo

BACKGROUND

Skin infections account for a high disease burden in indigenous children living in northern Australia. Although the relationship between impetigo and scabies is recognized, the prevalence of scabies in children with impetigo is not well reported. We report the prevalence, demographics and treatment success outcomes of impetigo and scabies coinfection in indigenous children who were participants in a randomized controlled trial of impetigo treatment conducted in remote communities of the Northern Territory, Australia.

METHODS

Of 1715 screening episodes for impetigo, 508 children were randomized to receive intramuscular benzathine benzylpenicillin (BPG), twice daily co-trimoxazole (SXT) for 3 days (4 mg/kg trimethoprim plus 20 mg/kg sulfamethoxazole per dose) or once daily SXT for 5 days (8 mg/kg trimethoprim plus 40 mg/kg sulfamethoxazole per dose). A clinical diagnosis of scabies; tinea of the skin, scalp or nail; and head lice was made on all children. Scabies presence was not confirmed using diagnostic scrapings. In a post-hoc analysis, we determined whether coinfection with scabies had an impact on treatment success for impetigo.

RESULTS

Of children randomized to receive treatment for impetigo, 84 of 508 (16.5%) had scabies. The presence of scabies ranged from 14.3% to 20.0% in the 3 treatment groups. Treatment success for impetigo with and without scabies coinfection, independent of the treatment groups, was 75.9% and 86.6%, respectively, absolute difference 10.7% [95% confidence interval (CI): +1% to +21%]. Treatment success for impetigo with and without scabies coinfection in the BPG group was 69.6% and 88.0%, respectively, absolute difference 18.4% (95% CI: -1% to +38%). In the pooled SXT groups, the treatment success for impetigo with and without scabies coinfection was 78.6% and 86.0%, respectively, with absolute difference 7.4% (95% CI: -4% to +18%). Treatment success in the pooled SXT group with scabies (78.6%) was higher than in the BPG group (69.6%) with scabies, absolute difference 9.0% (95% CI: +0.1% to +18%). Prediction of treatment success for impetigo is dependent on the presence or absence of scabies and for scabies coinfected impetigo it was higher in the group treated with SXT.

CONCLUSIONS

The burden of scabies in an impetigo trial for Indigenous children was high. Treatment success for scabies coinfection was lower than for impetigo overall, with a higher success seen in the SXT group than the BPG group.

Mitochondrial Genome Sequence of the Scabies Mite Provides Insight into the Genetic Diversity of Individual Scabies Infections

The scabies mite, Sarcoptes scabiei, is an obligate parasite of the skin that infects humans and other animal species, causing scabies, a contagious disease characterized by extreme itching. Scabies infections are a major health problem, particularly in remote Indigenous communities in Australia, where co-infection of epidermal scabies lesions by Group A Streptococci or Staphylococcus aureus is thought to be responsible for the high rate of rheumatic heart disease and chronic kidney disease. We collected and separately sequenced mite DNA from several pools of thousands of whole mites from a porcine model of scabies (S. scabiei var. suis) and two human patients (S. scabiei var. hominis) living in different regions of northern Australia. Our sequencing samples the mite and its metagenome, including the mite gut flora and the wound micro-environment. Here, we describe the mitochondrial genome of the scabies mite. We developed a new de novo assembly pipeline based on a bait-and-reassemble strategy, which produced a 14 kilobase mitochondrial genome sequence assembly. We also annotated 35 genes and have compared these to other Acari mites. We identified single nucleotide polymorphisms (SNPs) and used these to infer the presence of six haplogroups in our samples, Remarkably, these fall into two closely-related clades with one clade including both human and pig varieties. This supports earlier findings that only limited genetic differences may separate some human and animal varieties, and raises the possibility of cross-host infections. Finally, we used these mitochondrial haplotypes to show that the genetic diversity of individual infections is typically small with 1–3 distinct haplotypes per infestation.

The scabies mite is a skin parasite that infects humans and other animal species, causing scabies, a contagious disease characterized by extreme itching. Scabies infections are a major health problem in developing countries and in indigenous Australian populations, where scabies is associated with pyoderma (skin sores) and linked to rheumatic fever and rheumatic heart disease. Little is known about the genetics of the scabies mite. We have assembled the mitochondrial genome of scabies mites obtained from human patients in Australia and from a pig model. While investigating the genetic diversity of each infestation, we found that mitochrondial genomes clustered into two broad clades and showed limited genetic diversity within each infestation. Remarkably, one closely related clade included both human and pig mites, suggesting that mite transmission from pig to human may be possible. This could have major implications in the management of porcine mange and human scabies.

Therapeutic Potential of Tea Tree Oil for Scabies

Globally, scabies affects more than 130 million people at any time. In the developed world, outbreaks in health institutions and vulnerable communities result in a significant economic burden. A review of the literature demonstrates the emergence of resistance toward classical scabicidal treatments and the lack of effectiveness of currently available scabicides in reducing the inflammatory skin reactions and pyodermal progression that occurs in predisposed patient cohorts. Tea tree oil (TTO) has demonstrated promising acaricidal effects against scabies mites in vitro and has also been successfully used as an adjuvant topical medication for the treatment of crusted scabies, including cases that did not respond to standard treatments. Emerging acaricide resistance threatens the future usefulness of currently used gold standard treatments (oral ivermectin and topical permethrin) for scabies. The imminent development of new chemical entities is doubtful. The cumulative acaricidal, antibacterial, antipruritic, anti-inflammatory, and wound healing effects of TTO may have the potential to successfully reduce the burden of scabies infection and the associated bacterial complications. This review summarizes current knowledge on the use of TTO for the treatment of scabies. On the strength of existing data for TTO, larger scale, randomized controlled clinical trials are warranted.

A Retrospective Case-Series of Children With Bone and Joint Infection From Northern Australia

Our clinical workload as infectious diseases pediatricians in northern Australia is dominated by complicated bone and joint infections in indigenous children. We reviewed the clinical presentation, microbiology, management, and outcomes of children presenting to Royal Darwin Hospital with bone and joint infections between 2010 and 2013, and aimed to compare severity and incidence with other populations worldwide.A retrospective audit was performed on children aged 0 to 18 years who were admitted to Royal Darwin Hospital between 1 January 2010 and 31 December 2013 with a bone and joint infection.Seventy-nine patients were identified, of whom 57 (72%) had osteomyelitis ± associated septic arthritis and 22 (28%) had septic arthritis alone. Sixty (76%) were indigenous Australians. The incidence rate of osteomyelitis for indigenous children was 82 per 100,000 children. Staphylococcus aureus was the confirmed pathogen in 43/79 (54%), of which 17/43 (40%) were methicillin resistant. Median length of stay was 17 days (interquartile range: 10-31 days) and median length of IV antibiotics was 15 days (interquartile range: 6-24 days). Fifty-six (71%) required at least 1 surgical procedure. Relapse within 12 months was documented in 12 (15%) patients.We report 3 key findings: osteomyelitis incidence in indigenous children of northern Australia is amongst the highest reported in the world; methicillin-resistant S aureus accounts for 36% of osteomyelitis with a positive microbiological diagnosis; and the severity of disease requires extended antibiotic therapy. Despite this, 15% of the cohort relapsed within 12 months and required readmission.