Menzies School of Health Research

A key determinant of diet quality in outer regional to very remote areas is the higher cost of food. This systematic scoping review aims to identify evidence gaps on drivers of the cost of food, to guide future research and policy development to improve food security across outer regional to very remote areas of Australia. The Joanna Briggs Institute three step literature search was utilised and the review was conducted in accordance with PRISMA guidelines. Five electronic databases (Ovid MEDLINE, CINAHL, Informit, Embase, Scopus) were systematically searched in September 2024. Peer-reviewed literature set in outer regional to very remote regions of Australia were included if they were on the topic of food and food price and the drivers influencing these. Title and abstract screening were performed by two authors, as well as double screening of full texts by two authors. Data were extracted from included articles regarding remoteness category, aims, sampling, methodology, drivers influencing food price, outcomes and implications on policy, as well as author commentary on the drivers of food price. The CREATE tool for research involving Aboriginal and Torres Strait Islander communities was completed by two authors, with guidance from two First Nations authors and the senior author. Twenty articles published between 1987 to 2022 met the inclusion criteria. Most studies reported on remoteness itself as the determinant of high food price. Other drivers of food price included freight, high operating costs of smaller stores and weather events. Those living in outer regional to very remote Australia pay more for food, however there is a lack of empirical detailed evidence on the drivers of higher food price. To effectively address the higher cost of food in outer regional, rural, and remote Australia and promote food security in these areas, empirical evidence on system determinants could complement existing expert evidence for targeted policy and government support.

Splenic rupture is a recognized complication of acute Plasmodium falciparum and Plasmodium vivax malaria, but the risk of splenic rupture in chronic asymptomatic infections is unknown. In Timika, Papua, Indonesia, we determined the proportion of PCR-detectable asymptomatic peripheral parasitemia in patients undergoing trauma-related splenectomy (2015-21) and found it was more than twice the proportion compared to a 2013 household survey of the general population (87.9% [29/33] vs 38.6% [697/1807]; P < .0001). Our findings suggest asymptomatic parasitemia with either P. falciparum or P. vivax is associated with splenic rupture following trauma, pointing toward an additional consequence of chronic infection in malaria-endemic areas.

Risk prediction models for community-acquired pneumonia (CAP) in hospitalised children are limited, especially in upper-middle-income countries. We developed a PaEdiatric Pneumonia Severity (PEPS) score to aid early risk stratification and examined its discriminatory ability. Prospective cohort study. Between April 2022 and April 2023, children aged 1 month to <12 years hospitalised with radiographic-confirmed CAP were enrolled in Sabah, Malaysia. Key clinical factors were collected to develop risk profiles for mild, moderate, and severe CAP. The PEPS score was derived from the final multivariable model and its ability to discriminate CAP severity assessed. Among 868 children, 639 (73.6%) had mild, 83 (9.6%) moderate, and 146 (16.8%) severe CAP. Independent factors associated with moderate/severe CAP were age <6 months (adjusted OR (ORadj)=6.81, 95% CI 4.65 to 9.98), partial/unvaccinated status (ORadj=2.66, 95% CI 1.47 to 4.81), vomiting/refusal of feeds (ORadj=1.77, 95% CI 1.19 to 2.61), hypoxaemia (oxygen saturation 90-93% (ORadj=2.38, 95% CI 1.22 to 4.64); <90% (ORadj=28.88, 95% CI 13.37 to 62.35)) and anaemia (ORadj=1.76, 95% CI 1.17 to 2.67). The model demonstrated excellent discrimination in identifying risk of children having moderate/severe CAP (c-statistic=0.81, 95% CI 0.78 to 0.84). The developed PEPS score (0-13) stratified children into low-risk (score 0-1), moderate-risk (score 2-4) and high-risk (score ≥5) groups with observed rates of moderate/severe CAP 10.9%, 29.1%, and 76.9%, respectively, and demonstrated strong predictive performance for moderate/severe CAP (c-statistic=0.81, 95% CI 0.77 to 0.84). The PEPS score, the first developed in an upper-middle-income country using radiographic-confirmed CAP, accurately discriminates mild from moderate/severe hospitalised CAP. It may support case management in similar settings, but requires external validation before broader implementation.

Nontyphoidal Salmonella bacteria are an important global cause of gastrointestinal disease. In Australia, it is estimated that salmonellosis costs approximately 140 million Australian dollars per year in illness, pain and suffering, and other productivity losses. The Northern Territory (NT) of Australia is a sparsely populated tropical environment, with 31% of the population being Aboriginal Australians. We described the epidemiology of salmonellosis in the NT by analyzing routinely notified salmonellosis cases diagnosed between 2005 and 2024. We performed descriptive, univariate, and multivariate analyses. We used exact logistic regression to explore associations with severe disease (hospitalization or death). We performed negative binomial regression analysis to explore associations with length of hospitalization. There were 9628 salmonellosis notifications equating to a mean annual notification rate of 203 per 100,000 persons-the highest reported in the world; 51% of cases were male; 25.3% had severe disease (2432 hospitalizations and 18 deaths); and 50% were aged <5 years. The most commonly reported serotypes were S. Saintpaul (1125/9628, 11.7%), S. Virchow (1002/9628, 10.4%), and S. Typhimurium (936/9628, 9.7%). Aboriginal people were notified at 1.2 times (95% confidence interval [CI] 1.1-1.2, p < 0.001) the rate of non-Aboriginal people, were 3.7 times (95% CI 3.3-4.1, p < 0.001) more likely to experience severe disease, and were hospitalized for 1.6 times longer (95% CI 1.5-1.8, p < 0.001) than non-Aboriginal people. There was no difference in salmonellosis notification rates in 2005-2014 compared with 2015-2024; however, S. Typhimurium notifications decreased. The tropical climate, abundant wildlife, and contamination of the household environment with Salmonella contribute to high rates of salmonellosis in the NT. Credible interventions are needed to decrease the incidence of salmonellosis, particularly among young children exposed to contaminated tropical environments.

Melioidosis occurs in both humans and animals following exposure to and infection with Burkholderia pseudomallei in environmental soil and water. However, it should not be seen as a zoonosis, as transmission from animals to humans is exceptionally rare, as is transmission from person to person. In humans, melioidosis and severe disease are usually seen in people with clinical risk factors, most notably diabetes. Similarly, for animals, melioidosis is rarely seen in healthy species native to endemic regions, presumably reflecting co-evolution with B. pseudomallei over millennia. On the other hand, there is differential susceptibility among farm and grazing animals of non-tropical origins. Sheep, alpacas, and camels are especially susceptible, while with good animal husbandry, goats and pigs are farmed in some melioidosis-endemic regions. Melioidosis is seen in companion animals such as dogs and cats, mostly those in poor health. Melioidosis outbreaks have occurred in exotic animals imported into zoos in tropical cities, with tragic consequences for some iconic, critically endangered primate species. The clinical and pathological features seen in animals with melioidosis from natural exposure have been very informative for understanding the spectrum of disease in humans, including different clinical patterns reflecting whether the mode of infection was inhalational, percutaneous, or from ingestion of B. pseudomallei . There is a rapidly expanding global footprint of melioidosis, reflecting both unmasking of endemic disease with improved diagnostics and evolving spread of B. pseudomallei to new receptive locations, attributed to anthropogenic factors. In addition, case numbers in endemic regions have been on the rise and will likely continue to rise because of the triad of increasing numbers of people living with diabetes, environmental disturbance from construction activities with increasing urbanization, and climate change. It is hoped that over the next decade, the global map of the biogeographical boundaries of B. pseudomallei in the environment will be much further refined, enabling targeted support for the specific diagnostics and therapeutics required to minimize mortality from melioidosis. • Melioidosis is expanding globally due to both the unmasking of previously unknown endemic foci and the spread to new locations. • Humans and animals develop melioidosis from environmental exposure; zoonotic infection is exceedingly rare. • Pathology in animal melioidosis informs human disease. • Melioidosis can kill endangered primates imported to zoos in the tropics. • Increasing diabetes, urban construction, and climate change will drive increased cases of melioidosis.

BackgroundTo combat hepatocellular carcinoma (HCC) disease heterogeneity and growing mortality, there is an urgent need for targeted and personalized therapeutics. While syngeneic mouse models are commonly used for preclinical validation of these therapeutics, the lack of genetically characterized murine cell lines adds uncertainty to the study of drug‐gene interactions in these models. We previously generated a novel murine cell line, A52, from a diethylnitrosamine (DEN)‐induced adiponectin‐knockout mouse model. Here, we present a comprehensive genomic and transcriptomic characterization of the A52 cell line.MethodsA52 cells were grown in various culture medium compositions to investigate robustness to simple media. Whole‐genome sequencing (WGS) and RNAseq were performed on A52 cells from both cell culture and syngeneic tumor tissue, as well as a reference cell line representing non‐tumor cells, AML‐12.ResultsA52 was found to show robust growth in all medium compositions. Substantial chromosomal instability was observed in A52, including trisomy 15 and notable amplifications of oncogenic loci such as Myc and Cd274 (PDL‐1), alongside frequent small variants and structural rearrangements. Notably, the cell line harbors the common HCC driver Braf V584E mutation, and a novel Plk1 p.R364W variant predicted as a driver mutation. Transcriptomic profiling defined a distinct “A52 gene signature” enriched in EGFR‐ERBB signaling and cell migration pathways. Integrative analyses demonstrated that the A52 gene signature aligns closely with a subset of human HCC lacking CTNNB1 mutations.ConclusionThis study provides a critical genetic resource, facilitating more precise preclinical modeling and therapeutic validation in HCC.

Abstract Background Plasmodium vivax is the predominant cause of malaria in South Asia. P. vivax cases have fallen over the past decade, but cross-border transmission remains a major challenge to elimination. Genetic data can generate valuable insights into transmission; however, until now, only low-resolution data have been available from Nepal, Bhutan and Bangladesh. We piloted high-resolution genotyping using a new microhaplotype (multiallelic) assay to monitor P. vivax transmission across borders. Methods Genotyping was conducted using the 93-microhaplotype vivaxGEN panel on P. vivax parasites collected from patients enrolled in clinical trials in Bangladesh, Bhutan, and Nepal between 2013 and 2023. These data were compared with open-access microhaplotype and genomic data derived from Afghanistan, India, and Pakistan between 2014 and 2024. Polyclonality and relatedness (identity by descent (IBD)) were determined within and between countries. Results High-quality genotyping data were generated for Nepal (n = 19), Bhutan (n = 27), and Bangladesh (n = 35); comparative data were sourced from Afghanistan (n = 159), India (n = 24), and Pakistan (n = 213). Overall, 29.6% (47/159) of isolates from Afghanistan and 20.2% (43/213) from Pakistan had polyclonal infections, whereas all parasites from Bhutan, Nepal and Bangladesh were monoclonal, suggesting lower superinfection. Country-wide IBD analyses revealed three genetic clusters partitioning Bangladesh and Bhutan (partial) from the remaining countries. There were two sub-populations in Bhutan, which separated local and cross-border imported cases. Conclusions Our results highlight the use of regional high-resolution genetic data to enhance monitoring of transmission intensity and cross-border importations.

The clinical application of acoustic swallowing sound parameters collected from digital cervical auscultation is limited because of the time-consuming manual segmentation required by trained experts. The automated identification of swallowing sounds in children and adults from swallowing sound audio wavefiles using machine learning have accuracies between 76-95%. No data exists in preterm neonates. To determine if applying automated machine learning using a transfer learning approach could accurately identify and segment swallows from swallowing sounds collected in preterm neonates. Thin fluid swallow sounds were collected from 78 preterm neonates, median birth age 34weeks gestation (range 25-36weeks, 52.6% males) across 3 Australian special care nurseries. For the base machine learning model, a deep convolutional neural network (DCNN) pre-trained for audio event classification was used. With raw swallow audio data as input, embedding vectors from the base DCNN were generated and used to train a feedforward neural network to determine the presence of a swallow within an audio segment. The model showed high overall accuracy (94%) in identifying preterm swallows. Better model performance on bottle feeding swallows (Sensitivity, 95%; and specificity, 96%) was seen compared with breastfeeding swallows (sensitivity, 95%, specificity 92%). Interpretation: Our novel study demonstrates the successful use of transfer learning to accurately identify and segment digital swallowing sounds in preterm neonates. Application of this model could support the development of a digital CA app to automatically classify swallow sounds and improve objectivity for CA use in clinical practice within special care nurseries.

Pacific Australia Labour Mobility (PALM) scheme workers (hereafter referred to as PALM participants) are integral to Australia's economic landscape, contributing predominantly to agriculture and meatworks sectors. Many PALM participants come from regions with high burdens of blood-borne viruses (BBVs) such as hepatitis B virus (HBV), yet there is a lack of understanding of their Australian health experiences. This study explores the lived experiences of PALM participants, focusing on healthcare interactions and challenges faced in addressing health issues, particularly HBV and other BBVs. Eighteen semi-structured interviews with agricultural PALM participants from four Pacific Island countries were conducted and analysed thematically through an equity lens. A complex interplay of factors impacting health and healthcare system navigation was described, revealing challenges beyond HBV and other BBVs. Three overlapping themes are explored: (i) access issues, (ii) awareness and understanding; and (iii) 'battling the system'. PALM participants have significant unmet healthcare needs, with public health and economic implications. Greater political will is required to prioritise equitable healthcare for this population. SO WHAT?: This study highlights required changes to inform effective policies and interventions that promote health equity and improve health outcomes for PALM participants from Pacific Island countries and Timor Leste, particularly in relation to HBV and other BBVs.