Comprehensive observational study evaluating the enduring effectiveness of 4CMenB, the meningococcal B vaccine against gonococcal infections in the Northern Territory and South Australia, Australia: study protocol.

INTRODUCTION: The effectiveness of antibiotics for treating gonococcal infections is compromised due to escalating antibiotic resistance; and the development of an effective gonococcal vaccine has been challenging. Emerging evidence suggests that the licensed meningococcal B (MenB) vaccine, 4CMenB is effective against gonococcal infections due to cross-reacting antibodies and 95% genetic homology between the two bacteria, Neisseria meningitidis and Neisseria gonorrhoeae, that cause the diseases. This project aims to undertake epidemiological and genomic surveillance to evaluate the long-term protection of the 4CMenB vaccine against gonococcal infections in the Northern Territory (NT) and South Australia (SA), and to determine the potential benefit of a booster vaccine doses to provide longer-term protection against gonococcal infections. METHODS AND ANALYSES: This observational study will provide long-term evaluation results of the effectiveness of the 4CMenB vaccine against gonococcal infections at 4-7 years post 4CMenB programme implementation. Routine notifiable disease notifications will be the basis for assessing the impact of the vaccine on gonococcal infections. Pathology laboratories will provide data on the number and percentage of N. gonorrhoeae positive tests relative to all tests administered and will coordinate molecular sequencing for isolates. Genome sequencing results will be provided by SA Pathology and Territory Pathology/New South Wales Health Pathology, and linked with notification data by SA Health and NT Health. There are limitations in observational studies including the potential for confounding. Confounders will be analysed separately for each outcome/comparison. ETHICS AND DISSEMINATION: The protocol and all study documents have been reviewed and approved by the SA Department for Health and Well-being Human Research Ethics Committee (HREC/2022/HRE00308), and the evaluation will commence in the NT on receipt of approval from the NT Health and Menzies School of Health Research Human Research Ethics Committee. Results will be published in peer-reviewed journals and presented at scientific meetings and public forums.

Bronchiectasis among Indigenous adults in the Top End of the Northern Territory, 2011-2020: a retrospective cohort study.

OBJECTIVES: To assess the prevalence of bronchiectasis among Aboriginal and Torres Strait Islander (Indigenous) adults in the Top End of the Northern Territory, and mortality among Indigenous adults with bronchiectasis. STUDY DESIGN: Retrospective cohort study. SETTING, PARTICIPANTS: Aboriginal and Torres Strait Islander adults (18 years or older) living in the Top End Health Service region of the NT in whom bronchiectasis was confirmed by chest computed tomography (CT) during 1 January 2011 - 31 December 2020. MAIN OUTCOME MEASURES: Prevalence of bronchiectasis, and all-cause mortality among Indigenous adults with CT-confirmed bronchiectasis - overall, by sex, and by health district - based on 2011 population numbers (census data). RESULTS: A total of 23 722 Indigenous adults lived in the Top End Health Service region in 2011; during 2011-2020, 459 people received chest CT-confirmed diagnoses of bronchiectasis. Their median age was 47.5 years (interquartile range [IQR], 39.9-56.8 years), 254 were women (55.3%), and 425 lived in areas classified as remote (93.0%). The estimated prevalence of bronchiectasis was 19.4 per 1000 residents (20.6 per 1000 women; 18.0 per 1000 men). The age-adjusted prevalence of bronchiectasis was 5.0 (95% CI, 1.4-8.5) cases per 1000 people in the Darwin Urban health area, and 18-36 cases per 1000 people in the three non-urban health areas. By 30 April 2023, 195 people with bronchiectasis had died (42.5%), at a median age of 60.3 years (IQR, 50.3-68.9 years). CONCLUSION: The prevalence of bronchiectasis burden among Indigenous adults in the Top End of the NT is high, but differed by health district, as is all-cause mortality among adults with bronchiectasis. The socio-demographic and other factors that contribute to the high prevalence of bronchiectasis among Indigenous Australians should be investigated so that interventions for reducing its burden can be developed.

A retrospective, longitudinal cohort study of trends and risk factors for preterm birth in the Northern Territory, Australia.

BACKGROUND: Preterm birth (PTB) is the single most important cause of perinatal mortality and morbidity in high income countries. In Australia, 8.6% of babies are born preterm but substantial variability exists between States and Territories. Previous reports suggest PTB rates are highest in the Northern Territory (NT), but comprehensive analysis of trends and risk factors are lacking in this region. The objective of this study was to characterise temporal trends in PTB among First Nations and non-First Nations mothers in the Top End of the NT over a 10-year period and to identify perinatal factors associated with the risk of PTB. METHODS: This was a retrospective population-based cohort study of all births in the Top End of the NT over the 10-year period from January 1st, 2008, to December 31st, 2017. We described maternal characteristics, obstetric complications, birth characteristics and annual trends in PTB. The association between the characteristics and the risk of PTB was determined using univariate and multivariate generalised linear models producing crude risk ratios (cRR) and adjusted risk ratios (aRR). Data were analysed overall, in First Nations and non-First Nations women. RESULTS: During the decade ending in 2017, annual rates of PTB in the Top End of the NT remained consistently close to 10% of all live births. However, First Nations women experienced more than twice the risk of PTB (16%) compared to other women (7%). Leading risk factors for PTB among First Nations women as compared to other women included premature rupture of membranes (RR 12.33; 95% CI 11.78, 12.90), multiple pregnancy (RR 7.24; 95% CI 6.68, 7.83), antepartum haemorrhage (RR 4.36; 95% CI 3.93, 4.84) and pre-existing diabetes (RR 4.18; 95% CI 3.67, 4.76). CONCLUSIONS: First Nations women experience some of the highest PTB rates globally. Addressing specific pregnancy complications provides avenues for intervention, but the story is complex and deeper exploration is warranted. A holistic approach that also acknowledges the influence of socio-demographic influences, such as remote dwelling and disadvantage on disease burden, will be required to improve perinatal outcomes.

Impacts of Northern Territory banned drinker register on police recorded youth assault.

INTRODUCTION: In September 2017 the Northern Territory Government of Australia introduced a banned drinker register (BDR) to mitigate the high levels of alcohol-related harm within the Northern Territory. The current study aimed to examine the impact of the Northern Territory BDR on youth (aged <18 years) using police recorded assault data. METHODS: Interrupted time-series models were used to assess monthly trends in assaults and alcohol-related assaults perpetration and victimisation in the regions of Greater Darwin, Alice Springs and Katherine between January 2014 and December 2019. RESULTS: Examining the three regions combined, after the re-introduction of the BDR a significant step decrease in police recorded youth assault perpetration (ß = -1.67) and a significant step increase in police recorded youth assault victimisation (ß = 1.40) was identified. However, no significant effects were identified at the individual region level. DISCUSSION AND CONCLUSIONS: Findings suggest that restricting alcohol consumption in high-risk adults through the BDR had a limited immediate effect in police recorded youth assaults. Individual level or contextual factors may have influenced both immediate and long-term impacts of the BDR, and as such, future policy design needs to support and empower community leaders across the policy development and implementation process. A wider evaluation of the BDR currently underway may provide additional understanding behind the mechanisms that underpin alcohol-related harm in the Northern Territory.

Police-recorded adult sexual assault in the Northern Territory, Australia: Alcohol involvement and alcohol policy effects.

INTRODUCTION: Between 2017 and 2018 three major alcohol policy changes were introduced in the Northern Territory (NT): the Banned Drinker Register, an individual-level ban enforced via ID scanners at takeaway outlets; a Minimum Unit Price on alcohol; and Police Auxiliary Liquor Inspectors, who monitor takeaway outlets to prevent purchase by people who do not have a legal place to consume alcohol. We aimed to: (i) describe alcohol-involved adult sexual assault in the NT; and (ii) estimate the impacts of these alcohol policies on police-recorded adult sexual assault. METHODS: We used victim records for sexual assault where victims were aged 15 years and over. We undertook descriptive analyses for the NT from 2014 to 2020 and used interrupted time series analysis to assess policy impacts across the NT and in Greater Darwin. RESULTS: In 2020, the NT adult victimisation rate was 105 per 100,000. A large minority (40%) of adult sexual assaults involved alcohol. Interrupted time series analyses showed no effect of the Banned Drinker Register or Minimum Unit Price on sexual assault across the NT or in Greater Darwin. DISCUSSION AND CONCLUSIONS: The rate of adult sexual assaults in the NT is extremely high and many involve alcohol. Neither the Banned Drinker Register or Minimum Unit Price were associated with changes in police-recorded adult sexual assault in Greater Darwin or across the NT. Due to small counts, we were unable to assess policy impacts in three of the four main towns, highlighting the challenges of assessing impacts of policies on sexual assault in small population areas.

Cystic lung disease in adult Indigenous Australians in the Northern Territory of Australia.

INTRODUCTION: Indigenous Australians have a high prevalence of chronic lung diseases. However, no previous studies have reported on cystic lung disease in an Indigenous patient cohort. METHODS: This report describes 20 adult Indigenous patients noted to have incidental lung cysts on chest computed tomography (CT) while being referred to undergo lung function tests in the Northern Territory of Australia. RESULTS: Of the total 20 Indigenous patients demonstrating presence of pulmonary cysts on chest CT scan, 13/20 (65%) were males with a mean age of 49.9 years (range 24-74 years), with no significant difference in age between males and females. The majority reported a smoking history and spirometry demonstrated moderate reduction in lung function parameters. While there was no pattern in the size or location of cysts, most demonstrated multiple cysts (55% had ≥5 cysts) with bilateral involvement (65%), alongside a range of concurrent pulmonary radiological abnormalities. The aetiology for lung cysts was largely unknown. CONCLUSION: This is the first report to illustrate cystic lung disease within an Indigenous population. Further radiology studies are required to investigate the causes and prognostications of cystic lung disease in Indigenous patients.

Predicting child development and school readiness, at age 5, for Aboriginal and non-Aboriginal children in Australia's Northern Territory.

BACKGROUND: Positive early development is critical in shaping children's lifelong health and wellbeing. Identifying children at risk of poor development is important in targeting early interventions to children and families most in need of support. We aimed to develop a predictive model that could inform early support for vulnerable children. METHODS: We analysed linked administrative records for a birth cohort of 2,380 Northern Territory children (including 1,222 Aboriginal children) who were in their first year of school in 2015 and had a completed record from the Australian Early Development Census (AEDC). The AEDC measures early child development (school readiness) across five domains of development. We fitted prediction models, for AEDC weighted summary scores, using a Partial Least Square Structural Equation Model (PLS-SEM) considering four groups of factors-pre-pregnancy, pregnancy, known at birth, and child-related factors. We first assessed the models' internal validity and then the out-of-sample predictive power (external validity) using the PLSpredict procedure. RESULT: We identified separate predictive models, with a good fit, for Aboriginal and non-Aboriginal children. For Aboriginal children, a significant pre-pregnancy predictor of better outcomes was higher socioeconomic status (direct, ß = 0.22 and indirect, ß = 0.16). Pregnancy factors (gestational diabetes and maternal smoking (indirect, ß = -0.09) and child-related factors (English as a second language and not attending preschool (direct, ß = -0.28) predicted poorer outcomes. Further, pregnancy and child-related factors partially mediated the effects of pre-pregnancy factors; and child-related factors fully mediated the effects of pregnancy factors on AEDC weighted scores. For non-Aboriginal children, pre-pregnancy factors (increasing maternal age, socioeconomic status, parity, and occupation of the primary carer) directly predicted better outcomes (ß = 0.29). A technical observation was that variance in AEDC weighted scores was not equally captured across all five AEDC domains; for Aboriginal children results were based on only three domains (emotional maturity; social competence, and language and cognitive skills (school-based)) and for non-Aboriginal children, on a single domain (language and cognitive skills (school-based)). CONCLUSION: The models give insight into the interplay of multiple factors at different stages of a child's development and inform service and policy responses. Recruiting children and their families for early support programs should consider both the direct effects of the predictors and their interactions. The content and application of the AEDC measurement need to be strengthened to ensure all domains of a child's development are captured equally.

A cluster of leptospirosis cases associated with crocodile workers in the Northern Territory, Australia, 2022.

Leptospirosis is a worldwide zoonotic waterborne disease endemic in tropical and subtropical climates. Outbreaks have been observed in the Northern Territory (NT) of Australia. We briefly described the epidemiology of leptospirosis in the NT between 2012 and 2022, and undertook an investigation of a cluster of three leptospirosis cases observed in crocodile workers between January and December 2022 in the Top End of the NT. A descriptive case series was conducted to investigate the cluster; all three cases were male and non-Aboriginal with a median age of 46.5 years; none took chemoprophylaxis; only one of the three cases reported wearing appropriate protective attire; all reported receiving limited to no education about personal protective measures from their associated workplaces. Higher than average rainfall in both February and December 2022 likely contributed to the increased risk of infection in those months. Changing climate patterns are likely to result in more frequent periods of heavy rain, and risk of contracting leptospirosis in the NT may increase, particularly for those who work in wet and muddy conditions. Promoting the use of protective workplace clothing and equipment, the use of waterproof dressings for skin abrasions, regular hand hygiene, and the consideration of chemoprophylaxis in certain circumstances may prevent future cases.

An evaluation of the quality of ear health services for Aboriginal children living in remote Australia: a cascade of care analysis.

BACKGROUND: In the Northern Territory (NT) the prevalence of otitis media (OM) in young Aboriginal children living in remote communities has persisted at around 90% over the last few decades. OM-associated hearing loss can cause developmental delay and adversely impact life course trajectories. This study examined the 5-year trends in OM prevalence and quality of ear health services in remote NT communities. METHODS: A retrospective analysis was performed on de-identified clinical data for 50 remote clinics managed by the NT Government. We report a 6-monthly cascade analysis of the proportions of children 0-16 years of age receiving local guideline recommendations for surveillance, OM treatment and follow-up at selected milestones between 2014 and 2018. RESULTS: Between 6,326 and 6,557 individual children were included in the 6-monthly analyses. On average, 57% (95%CI: 56-59%) of eligible children had received one or more ear examination in each 6-monthly period. Of those examined, 36% (95%CI: 33-40%) were diagnosed with some type of OM, of whom 90% had OM requiring either immediate treatment or scheduled follow-up according to local guidelines. Outcomes of treatment and follow-up were recorded in 24% and 23% of cases, respectively. Significant decreasing temporal trends were found in the proportion diagnosed with any OM across each age group. Overall, this proportion decreased by 40% over the five years (from 43 to 26%). CONCLUSIONS: This cascade of care analysis found that ear health surveillance and compliance with otitis media guidelines for treatment and follow-up were both low. Further research is required to identify effective strategies that improve ear health services in remote settings.

Alcohol-Attributable Death and Burden of Illness among Aboriginal and Non-Aboriginal Populations in Remote Australia, 2014-2018.

Harmful use of alcohol is a problem in the Northern Territory (NT), Australia. The aim of this study was to assess and compare alcohol-attributable deaths and the contribution of alcohol to the burden of disease and injury (BOD) among the Aboriginal and non-Aboriginal populations in the NT between 2014 and 2018. The alcohol-use data for adults aged 15+ years old in the NT population was taken from the 2016 National Drug Strategy Household Survey. BOD was measured in disability-adjusted life years (DALY) as part of the NT BOD study. Population-attributable fractions were derived to analyse deaths and BOD. Between 2014 and 2018, 673 Aboriginal and 392 non-Aboriginal people died of harmful use of alcohol, accounting for 26.3% and 12.9% of the total deaths in the Aboriginal and non-Aboriginal population, respectively. Alcohol caused 38,596 and 15,433 DALY (19.9% and 10.2% of the total), respectively, in the NT Aboriginal and non-Aboriginal population for the same period. The alcohol-attributable DALY rate in the Aboriginal population was 10,444.6 per 100,000 persons, six times the non-Aboriginal rate. This study highlights the urgent need to reduce harmful alcohol use in the NT, which disproportionately affects Aboriginal peoples in rural and remote areas.

Socio-environmental and clinical features of invasive group A streptococcal disease in the Northern Territory of Australia.

Objective: To describe the socio-environmental profile and clinical features of invasive group A streptococcal (iGAS) infections in the Northern Territory (NT) of Australia over 10 years. Methods: Cases of iGAS disease diagnosed between 1 May 2011 and 30 April 2021 were retrospectively identified from the NT Notifiable Diseases System and electronic health records accessed. Remoteness of residence, socio-economic index, seasonality and clinical characteristics were recorded. Results: There were 692 cases of iGAS disease identified in the NT during the period 1 May 2011 - 30 April 2021. The age-standardised incidence of iGAS disease was significantly higher in people living in very remote (57.1 cases per 100,000 population, 95% confidence interval [95% CI]: 48.6-65.5) and remote areas (40.9 cases per 100,000 population, 95% CI: 34.7-47.2) than in outer regional areas of the NT (15.7 cases per 100,000 population, 95% CI: 13.4-17.9). People with socio-economic disadvantage were also disproportionately affected, with an incidence of 52.6 cases per 100,000 population (95% CI: 46.2-58.9) in decile 1-3 populations, compared to 8.9 cases per 100,000 population (95% CI: 6.9-10.9) for decile 7-10. For cases with recorded severity data, 135 of 378 (36%) met locally-defined criteria for severe iGAS disease. Recurrent iGAS disease was commonly observed in the dialysis cohort, affecting 17 of the 106 patients during the study period (16% recurrence rate) and causing two deaths. Five molecularly-confirmed clusters of iGAS disease were identified from the study period. Conclusions: iGAS disease is unevenly affecting people in the NT. Those living in areas of socio-economic disadvantage, those in remote and very remote communities, and those receiving dialysis were most affected. It is important that primordial, primary and secondary prevention measures be directed towards supporting these disadvantaged population groups.

Group B streptococcus in the Northern Territory in 2023: clindamycin down but not out.

Group B streptococcus (GBS) is a significant cause of perinatal morbidity and mortality; prophylactic antibiotics in the obstetric population can mitigate the risk of neonatal infection. The antibiotic of choice is penicillin; however, in women who have a penicillin hypersensitivity, clindamycin is the preferred agent. Worldwide resistance to clindamycin is rising in GBS isolates. In the Top End of the Northern Territory of Australia, we reviewed 113 GBS isolates in 2023. These GBS isolates revealed a 30% resistance to clindamycin. This rate has considerably increased since the Australia-wide survey published in 2011 where GBS resistance to clindamycin was quoted at 4.2%. As a result of this study, we are advocating for a change in practice in patients with known GBS resistance with penicillin hypersensitivity.

Case Report: Catastrophic Effects of Using Cannabis Via Bucket Bong in Top End Northern Territory of Australia.

The prevalence of cannabis usage is increasing worldwide, including among both Indigenous and non-Indigenous Australians. The long-term effects of cannabis use on the lungs are well-known. However, the acute adverse effects on the lungs are sparsely reported. There are different ways in which cannabis can be inhaled, such as smoking or through a water vaporizing method known as a "bong." An improvised innovative bong device that is commonly used in Northern Australia, called a "bucket bong," uses water and air pressure to assist in cannabis inhalation. In this report, we describe three patients from remote and rural Northern Australian communities presenting with near-life-threatening events (acute pneumonitis and massive pneumothorax) immediately after the use of cannabis via bucket bong.

External validation of the Health Care Homes hospital admission risk stratification tool in the Aboriginal Australian population of the Northern Territory.

Objective This study aimed to externally validate the Commonwealth's Health Care Homes (HCH) algorithm for Aboriginal Australians living in the Northern Territory (NT). Methods A retrospective cohort study design using linked primary health care (PHC) and hospital data was used to analyse the performance of the HCH algorithm in predicting the risk of hospitalisation for the NT study population. The study population consisted of Aboriginal Australians residing in the NT who have visited a PHC clinic at one of the 54 NT Government clinics at least once between 1 January 2013 and 31 December 2017. Predictors of hospitalisation included demographics, patient observations, medications, diagnoses, pathology results and previous hospitalisation. Results There were a total of 3256 (28.5%) emergency attendances or preventable hospitalisations during the study period. The HCH algorithm had an area under the receiver operating characteristic curve (AUC) of 0.58 for the NT remote Aboriginal population, compared with 0.66 in the Victorian cohort. A refitted model including 'previous hospitalisation' had an AUC of 0.72, demonstrating better discrimination than the HCH algorithm. Calibration was also improved in the refitted model, with an intercept of 0.00 and a slope of 1.00, compared with an intercept of 1.29 and a slope of 0.55 in the HCH algorithm. Conclusion The HCH algorithm performed poorly on the NT cohort compared with the Victorian cohort, due to differences in population demographics and burden of disease. A population-specific hospitalisation risk algorithm is required for the NT.

Sydenham chorea in the top end of Australia's Northern Territory: A 20-year retrospective case series.

AIM: Sydenham chorea is an immune-mediated neuropsychiatric condition, and a major criterion for diagnosis of acute rheumatic fever (ARF). Children in remote Northern Australia experience disproportionately high rates of ARF, yet studies looking at the epidemiology, clinical presentation and management of Sydenham chorea are limited in this population. METHODS: We conducted a retrospective case series from January 2002 to April 2022 of all paediatric patients aged ≤18 years admitted to Royal Darwin Hospital with Sydenham chorea. Cases were identified using the hospital's clinical coding system (ICD10). Medical records were reviewed and data on demographics, clinical presentation, investigation results, treatment and outcome were extracted, deidentified and analysed. RESULTS: One hundred ten presentations of Sydenham chorea occurred between 2002 and 2022, 109 (99%) of these were in First Nations children, with 85% residing in very remote locations. Most commonly, chorea presented as a generalised movement disorder affecting all four limbs (49%). Neuropsychiatric symptoms were reported in 33 (30%), and there was evidence of rheumatic heart disease on echocardiogram in 86 (78%) at presentation. All patients received benzathine penicillin, but there was significant variation in management of chorea, ranging from supportive management, to symptomatic management with anticonvulsants, to immunomodulatory medications including corticosteroids. CONCLUSION: This case series highlights the significant burden of Sydenham chorea among First Nations children living in Northern Australia and demonstrates wide variation in treatment approaches. High-quality clinical trials are required to determine the best treatment for this disabling condition.

Aldosterone and renin concentrations and blood pressure in young Indigenous and non-Indigenous adults in the Northern Territory: a cross-sectional study.

OBJECTIVES: To evaluate aldosterone and renin levels and aldosterone-to-renin ratios (ARRs) in young Indigenous and non-Indigenous adults in the Northern Territory, and their association with blood pressure levels. DESIGN: Cross-sectional study; single time point sub-study of two prospective birth cohort studies. SETTING, PARTICIPANTS: Participants in the Aboriginal Birth Cohort (ABC) - born to Indigenous mothers at the Royal Darwin Hospital during 1987-1990 - and the Top End Cohort (TEC) - people born to non-Indigenous mothers in Darwin, recruited during 2007-2009 - aged 32-35 years at the time of this sub-study. MAIN OUTCOME MEASURES: Plasma aldosterone and direct renin concentrations; ARRs (positive screening test result for primary aldosteronism defined as > 70 pmol/mU); systolic and diastolic blood pressure. RESULTS: A total of 255 ABC (205 in remote, 50 in urban locations) and 76 TEC members participated. Median aldosterone concentration was similar for all three groups. The median renin concentration was 7.5 mU/L (interquartile range [IQR], 4.1-12.4 mU/L) in the TEC group, 12.4 mU/L (IQR, 5.1-19 mU/L) in the urban ABC group, and 29.3 mU/L (IQR, 15.0-52.9 mU/L) in the remote ABC group. The median ARR was 10 pmol/mU (IQR, 6-19 pmol/mU) in the remote ABC group, 28 pmol/mU (IQR, 16-70 pmol/mU) in the urban ABC group, and 43 pmol/mU (IQR, 26-74 pmol/mU) in the TEC group. Thirteen urban ABC participants (26%), 21 TEC participants (28%), and six people in the remote ABC group (3%) had ARR values above 70 pmol/mU. Adjusted for age and body mass index (BMI), mean systolic and diastolic blood pressure were lower for women than men in all participant groups; after adjusting for age, sex, and BMI, larger ARR was associated with higher systolic blood pressure in the TEC group but not the two ABC groups. CONCLUSION: Screening test results for primary aldosteronism were positive for about one-quarter of urban Indigenous and non-Indigenous participants. A prospective study that includes confirmatory testing would more accurately assess the prevalence of primary aldosteronism among Indigenous Australians in the Northern Territory.

Non-tuberculous mycobacterial skin and soft tissue infections in the Northern Territory, Australia, 1989-2021.

BACKGROUND: A previous review demonstrated that the majority of NTM infections in the Northern Territory (NT) are pulmonary in nature [1], however skin and soft tissue (SST) are likely the next most common sites of disease. The current epidemiology of NTM SST infections across the NT is not known. We aimed to establish the current and historical incidence rates, and the organisms involved. METHODS: All NTM cases reported to the Centre for Disease Control in Darwin from 1989-2021 were retrospectively reviewed. RESULTS: 226 NTM notifications were reviewed. 73 (32%) cases were SST infections. The incidence of SST cases increased over the study period. Female cases were more common (p=0·002). Disease occurred across a wide age range (1-85 years). Only 16% of cases occurred in Aboriginal individuals which may reflect immunological factors requiring further investigation. Many cases had no clear provocation, but localised skin trauma was the most common risk factor. The most common organism identified was M. fortuitum (41%). Diagnosis was often delayed, with a median time to diagnosis of 69 days (IQR=31-149). Most cases (60%) underwent surgical intervention with adjunctive anti-mycobacterial medical therapy. CONCLUSION: NTM SST incidence rates increased over the study period. NTM SST infections are a rare but important differential diagnosis for non-healing cutaneous wounds.

Estimating the impact of the minimum alcohol price on consumers' alcohol expenditure in the Northern Territory, Australia.

OBJECTIVE: From October 2018, the Northern Territory (NT) government introduced a minimum unit price (MUP) for alcohol of $1.30 per standard drink. We assessed industry claims that the MUP penalised all drinkers by examining the alcohol expenditure of drinkers not targeted by the policy. METHODS: Participants recruited by a market research company using phone sampling (n=766, 15% consent fraction) completed a survey in 2019, post-MUP. Participants reported their drinking patterns and their preferred liquor brand. Estimated annual alcohol expenditure for each participant was calculated by collating the cheapest advertised price per standard drink of their preferred brand pre-and-post-MUP. Participants were grouped as consuming within the Australian drinking guidelines ("moderate") or over them ("heavy"). RESULTS: Based on post-MUP drinking patterns, moderate consumers had an average annual alcohol expenditure of AU$327.66 (CIs=325.61, 329.71) pre-MUP, which increased by AU$3.07 (0.94%) post-MUP. Heavy consumers had an estimated average annual alcohol expenditure of AU$2898.82 (CIs=2877.06, 2920.58) pre-MUP, which increased by AU$37.12 (1.28%). CONCLUSIONS: The MUP policy was associated with an increase of AU$3.07 in alcohol annual expenditure for moderate consumers. IMPLICATIONS FOR PUBLIC HEALTH: This article provides evidence that counters the alcohol industry's messaging, enabling an evidence-based discussion in an area dominated by vested interest.

Characterisation of Corynebacterium diphtheriae isolates in the Northern Territory of Australia.

This article summarises our review of 41 Corynebacterium diphtheriae wound swab isolates from the tropical Northern Territory of Australia. On polymerase chain reaction and whole genome sequencing, no isolates were toxigenic strains.

Evaluating the role of asymptomatic throat carriage of Streptococcus pyogenes in impetigo transmission in remote Aboriginal communities in Northern Territory, Australia: a retrospective genomic analysis.

BACKGROUND: Streptococcus pyogenes, or group A Streptococcus (GAS), infections contribute to a high burden of disease in Aboriginal Australians, causing skin infections and immune sequelae such as rheumatic heart disease. Controlling skin infections in these populations has proven difficult, with transmission dynamics being poorly understood. We aimed to identify the relative contributions of impetigo and asymptomatic throat carriage to GAS transmission. METHODS: In this genomic analysis, we retrospectively applied whole genome sequencing to GAS isolates that were collected as part of an impetigo surveillance longitudinal household survey conducted in three remote Aboriginal communities in the Northern Territory of Australia between Aug 6, 2003, and June 22, 2005. We included GAS isolates from all throats and impetigo lesions of people living in two of the previously studied communities. We classified isolates into genomic lineages based on pairwise shared core genomes of more than 99% with five or fewer single nucleotide polymorphisms. We used a household network analysis of epidemiologically and genomically linked lineages to quantify the transmission of GAS within and between households. FINDINGS: We included 320 GAS isolates in our analysis: 203 (63%) from asymptomatic throat swabs and 117 (37%) from impetigo lesions. Among 64 genomic lineages (encompassing 39 emm types) we identified 264 transmission links (involving 93% of isolates), for which the probable source was asymptomatic throat carriage in 166 (63%) and impetigo lesions in 98 (37%). Links originating from impetigo cases were more frequent between households than within households. Households were infected with GAS for a mean of 57 days (SD 39 days), and once cleared, reinfected 62 days (SD 40 days) later. Increased household size and community presence of GAS and scabies were associated with slower clearance of GAS. INTERPRETATION: In communities with high prevalence of endemic GAS-associated skin infection, asymptomatic throat carriage is a GAS reservoir. Public health interventions such as vaccination or community infection control programmes aimed at interrupting transmission of GAS might need to include consideration of asymptomatic throat carriage. FUNDING: Australian National Health and Medical Research Council.