A retrospective study of 191 cases of septic arthritis was undertaken at Royal Darwin Hospital in the tropical north of Australia. Incidence was 9.2 per 100,000 overall and 29.1 per 100,000 in Aboriginal Australians (RR 6.6; 95% CI 5.0-8.9). Males were affected more than females (RR 1.6; 95% CI 1.2-2.1). There was no previous joint disease or medical illness in 54%. The commonest joints involved were the knee (54%) and hip (13%). Significant age associations were infected hips in those under 15 years and infected knees in those over 45 years. Seventy two percent of infections were haematogenous. Causative organisms included Staphylococcus aureus (37%), Streptococcus pyogenes (16%) and Neisseria gonorrhoeae (12%). Unusual infections included three melioidosis cases. Polyarthritis occurred in 17%, with N. gonorrhoeae (11/23) more likely to present as polyarthritis than other organisms (22/168) (OR 6.0; 95% CI 2.1-16.7). Univariate and multivariate analysis showed the hip to be at greater risk for S. aureus than other joints. Open arthrotomy was a more successful treatment procedure than arthroscopic washout or needle aspiration.

Objectives: Crusted scabies (CS, Norwegian scabies) is a severe form of scabies, characterized by hyper-infestation of Sarcoptes scabiei mites. CS is commonly associated with immunosuppression but is also reported in overtly immunocompetent individuals. We reviewed immunosuppressive risk factors and comorbidities associated with CS. Methods: The National Library of Medicine (PubMed) database was reviewed for patient case reports of CS from January 1998 to July 2023. Two authors screened records for eligibility, extracted data, and one critically appraised the quality of the studies. Systematic review registration: PROSPERO CRD42023466126. Results: A total of 436 records were identified, of which 204 were included for systematic review. From these, 683 CS patients were included. CS impacted both genders equally. Adults (21-59 years) were more commonly affected (45.5%) compared to children (0-20 years, 21%). Corticosteroid use was the most prevalent immunosuppressive risk factor identified (27.7% of all cases). About 10.2% of reports were associated with HIV/AIDS, and 8.5% with HTLV-1 infection. 10.5% of patients were overtly immunocompetent with no known risk factors. Overall, 41 (6.0%) died, many subsequent to secondary bacteremia. Conclusion: This study represents the first systematic review undertaken on immunosuppressive risk factors associated with CS. This provides insights into trends of immunosuppression and mechanisms of CS development.

The apparent incidence of acute hepatitis B infection in the Top End of the Northern Territory was estimated from notification data and hospital data to be 12 per 100,000 per year, with a marked difference between Aborigines (42 per 100,000) and non-Aborigines (4 per 100,000), and an odds ratio of 9.7 (95 per cent confidence intervals 3 to 33). Sixty percent of Aboriginal cases of acute hepatitis B occurred in children under 10 years of age, whereas non-Aboriginal cases occurred in adults aged 20 to 29, most with behavioural risk factors. These findings confirm the importance of immunising Aboriginal children to reduce the future incidence of hepatitis B infection and hepatoma.

A key challenge to providing quality developmental care in remote Aboriginal primary health care (PHC) centers has been the absence of culturally appropriate developmental screening instruments. This study focused on the cross-cultural adaptation of the Ages and Stages Questionnaires, 3rd edition (ASQ-3), with careful attention to language and culture. We aimed to adapt the ASQ-3 for use with remote dwelling Australian Aboriginal children, and to investigate the cultural appropriateness and feasibility of the adapted ASQ-3 for use in this context. We undertook a qualitative study in two remote Australian Aboriginal communities, using a six-step collaborative adaptation process. Aboriginal Health Workers (AHWs) were trained to use the adapted ASQ-3, and follow-up interviews examined participants' views of the cultural acceptability and usefulness of the adapted instrument. The adapted ASQ-3 was found to have high face validity and to be culturally acceptable and relevant to parents, AHWs, and early childhood development experts.

We describe the recent temporal patterns of respiratory syncytial virus (RSV) and influenza virus detections in the Northern Territory (NT) of Australia, between 2020 and 2023.This retrospective analysis of patients presenting with respiratory diseases utilised a multiplex viral nucleic acid detection assay for RSV, influenza and SARS Cov2 (COVID-19) to determine the relative frequency of non-COVID-19 respiratory viral detections by age and month during the study period.During this period of the NT COVID-19 epidemic, disruption of the usual annual wet season RSV outbreak patterns occurred, and the yearly influenza peak was absent for two annual cycles. Our data also reveals that 25% of RSV infections were occurring in patients greater than 40 years of age, compared to 32% of influenza infections presenting in the same period, documenting a greater burden of adult disease than previously documented in the NT.Loss of non-COVID-19 viral seasonality and a substantial unrecognised RSV adult burden were noted. We will continue to monitor seasonality, and the RSV burden and this will help to target the populations benefiting from recently released RSV vaccine.

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.

The National Notifiable Diseases Surveillance System (NNDSS) received notification of 9,291 cases of disease transmitted by mosquitoes during the 2010-11 season (1 July 2010 to 30 June 2011). The alphaviruses Barmah Forest virus and Ross River virus accounted for 7,515 (81%) of these. There were 133 notifications of dengue virus infection acquired in Australia and 1,133 cases that were acquired overseas, while for 10 cases, the place of acquisition was unknown. The number of overseas acquired cases of dengue continues to rise each year, and these are most frequently acquired in Indonesia. Sentinel chicken, mosquito surveillance, viral detection in mosquitoes and climate modelling are used to provide early warning of arboviral disease activity in Australia. In early 2011, sentinel chickens in south eastern Australia widely seroconverted to flaviviruses. In 2010-11, there were 16 confirmed human cases of Murray Valley encephalitis acquired in Australia. There was one human case of Kunjin virus infection. There were 7 notifications of locally-acquired malaria in Australia and 407 notifications of overseas-acquired malaria during the 2010-11 season.

This report describes the epidemiology of mosquito-borne diseases of public health importance in Australia during the 2013-14 season (1 July 2013 to 30 June 2014) and includes data from human notifications, sentinel chicken, vector and virus surveillance programs. The National Notifiable Diseases Surveillance System received notifications for 8,898 cases of disease transmitted by mosquitoes during the 2013-14 season. The Australasian alphaviruses Barmah Forest virus and Ross River virus accounted for 6,372 (72%) total notifications. However, over-diagnosis and possible false positive diagnostic test results for these 2 infections mean that the true burden of infection is likely overestimated, and as a consequence, the case definitions have been amended. There were 94 notifications of imported chikungunya virus infection and 13 cases of imported Zika virus infection. There were 212 notifications of dengue virus infection acquired in Australia and 1,795 cases acquired overseas, with an additional 14 cases for which the place of acquisition was unknown. Imported cases of dengue were most frequently acquired in Indonesia (51%). No cases of locally-acquired malaria were notified during the 2013-14 season, though there were 373 notifications of overseas-acquired malaria. In 2013-14, arbovirus and mosquito surveillance programs were conducted in most jurisdictions. Surveillance for exotic mosquitoes at international ports of entry continues to be a vital part of preventing the spread of vectors of mosquito-borne diseases such as dengue to new areas of Australia, with 13 detections of exotic mosquitoes at the ports of entry in 2013-14.

BACKGROUND AND OBJECTIVE: Despite the high burden of respiratory disease amongst Indigenous populations, prevalence data on spirometric deficits and its determinants are limited. We estimated the prevalence of abnormal spirometry in young Indigenous adults and determined its relationship with perinatal and early life factors. METHODS: We used prospectively collected data from the Australian Aboriginal Birth Cohort, a birth cohort of 686 Indigenous Australian singletons. We calculated the proportion with abnormal spirometry (z-score <-1.64) and FEV(1) below the population mean (FEV(1) % predicted 0 to -2SD) measured in young adulthood. We evaluated the association between perinatal and early life exposures with spirometry indices using linear regression. RESULTS: Fifty-nine people (39.9%, 95%CI 31.9, 48.2) had abnormal spirometry; 72 (49.3%, 95%CI 40.9, 57.7) had a FEV(1) below the population mean. Pre-school hospitalisations for respiratory infections, younger maternal age, being overweight in early childhood and being born remotely were associated with reduced FEV(1) and FVC (absolute, %predicted and z-score). The association between maternal age and FEV(1) and FVC were stronger in women, as was hospitalization for respiratory infections before age 5. Being born remotely had a stronger association with reduced FEV(1) and FVC in men. Participants born in a remote community were over 6 times more likely to have a FEV(1) below the population mean (odds ratio [OR] 6.30, 95%CI 1.93, 20.59). CONCLUSION: Young Indigenous adults have a high prevalence of impaired lung function associated with several perinatal and early life factors, some of which are modifiable with feasible interventions.

The last epidemic of Australian encephalitis occurred in 1974. Since then, cases have been reported from the Kimberley of Western Australia (WA). To describe the epidemiology and clinical features of Australian encephalitis in the Northern Territory (NT) of Australia. Review of cases of Australian encephalitis presenting to Royal Darwin Hospital from 1987-1996 and review of sentinel chicken surveillance for Australian encephalitis viruses. Sixteen patients were identified; ten from the NT and six from WA. Cases occurred in the years 1987, 1988, 1991 and 1993. Infection was acquired throughout northern NT below latitude 20 degrees S in the months March to July. All infections were due to Murray Valley encephalitis (MVE) virus. Eleven of the patients were children. Distinguishing features were spinal cord and brainstem involvement and the absence of seizures in adults. CT scanning was normal and EEG showed no focal activity. Five died (31%) and four (25%) have residual neurological disability. Sentinel chicken surveillance since 1992 shows yearly seroconversion to MVE virus throughout northern NT; human cases occurred simultaneously with chicken seroconversion in 1993. Australian encephalitis is endemic in the NT; the areas at risk are north of Tennant Creek. Outbreaks are seasonal and occur every few years. Young children are most at risk. Mortality and morbidity are high. Prevention of disease is by avoidance of mosquito exposure and vector control measures.

Acute lower respiratory infections (ALRIs) remain the leading causes of repeated hospitalisations among young disadvantaged Australian and New Zealand First Nations and Timorese children. Severe (hospitalised) and recurrent ALRIs in the first years of life are associated with future chronic lung diseases (eg, bronchiectasis) and impaired lung function. Despite the high burden and long-term consequences of severe ALRIs, clinical, evidence-based and feasible interventions (other than vaccine programmes) that reduce ALRI hospitalisations in children are limited. This randomised controlled trial (RCT) will address this unmet need by trialling a commonly prescribed macrolide antibiotic (azithromycin) for 6-12 months. Long-term azithromycin was chosen as it reduces ALRI rates by 50% in Australian and New Zealand First Nations children with chronic suppurative lung disease or bronchiectasis. The aim of this multicentre, international, double-blind, placebo-containing RCT is to determine whether 6-12 months of weekly azithromycin administered to Australian and New Zealand First Nations and Timorese children after their hospitalisation with an ALRI reduces subsequent ALRIs compared with placebo. Our primary hypothesis is that children receiving long-term azithromycin will have fewer medically attended ALRIs over the intervention period than those receiving placebo.We will recruit 160 Australian and New Zealand First Nations and Timorese children aged <2 years to a parallel, superiority RCT across four hospitals from three countries (Australia, New Zealand and Timor-Leste). The primary outcome is the rate of medically attended ALRIs during the intervention period. The secondary outcomes are the rates and proportions of children with ALRI-related hospitalisation, chronic symptoms/signs suggestive of underlying chronic suppurative lung disease or bronchiectasis, serious adverse events, and antimicrobial resistance in the upper airways, and cost-effectiveness analyses.The Human Research Ethics Committees of the Northern Territory Department of Health and Menzies School of Health Research (Australia), Health and Disability Ethics Committee (New Zealand) and the Institute National of Health-Research Technical Committee (Timor-Leste) approved this study. The study outcomes will be disseminated to academic and medical communities via international peer-reviewed journals and conference presentations, and findings reported to health departments and consumer-based health organisations.Australia New Zealand Clinical Trial Registry ACTRN12619000456156.

This prospective study was designed to elucidate barriers limiting effective perioperative communication between indigenous Australians and anaesthetists, and to identify strategies for improving communication. A questionnaire was used to collect data on 1040 consecutive patients undergoing anaesthesia at Royal Darwin Hospital between February and March 2003. 27.1% of these patients described themselves as Aboriginal. Aboriginal patients were more likely to undergo emergency surgery and were more likely to be classified as ASA 3, 4 or 5 than non-indigenous patients. Communication difficulties were identified in 28.7% of all Aboriginal patients, which was 31 times higher than those in non-Aboriginal patients. The most common reason identified for this was difficulty in speaking English. Only 17.7% of Aboriginal patients presenting to the operating theatre spoke English as their first language. Unfortunately, the anaesthetic team utilized the Aboriginal interpreter service in only a minority of cases. Communication difficulty in indigenous Australians is pervasive and often goes unrecognized. The results suggest that heath care providers may need staff training in cross-cultural communication and that protocols need to be developed within the health care system so that interpreters are called upon automatically early in the admission process.

Recent studies suggest that infection with human T-lymphotropic virus 1 (HTLV-1) might be associated with bronchiectasis among Indigenous Australians. The present study compared the clinical characteristics and outcomes of bronchiectasis in this population, according to HTLV-1 serologic status. We performed a retrospective cohort study of Indigenous adults with bronchiectasis and known HTLV-1 serologic status admitted to Alice Springs Hospital, central Australia, from January 2000 through December 2006. Among 89 Indigenous adults whose HTLV-1 serologic status was confirmed, 52 (58.4%) were HTLV-1 seropositive. Differences between HTLV-1-seropositive and HTLV-1-seronegative groups were apparent in childhood presentations and adult outcomes. Among adults, an increasing number of bronchiectatic lobes (univariable odds ratio [OR], 1.51; 95% confidence interval [CI]; 1.03-2.20; P = .033) and the presence of ground-glass opacities at chest high-resolution computed tomography (univariable OR, 8.54; 95% CI, 1.04-70.03; P = .046) predicted HTLV-1 infection. Cor pumonale (HTLV-1-positive group, 10/52; HTLV-1-negative group, 1/37; P = .023) was more frequent among HTLV-1-seropositive adults, who also experienced a higher disease-specific mortality (univariable OR, 5.78; 95% CI, 1.17-26.75; P = .028). Only HTLV-1-seropositive patients were admitted specifically for the treatment of infected skin lesions, and this finding predicted death (multivariable OR, 6.77; 95% CI, 1.46-31.34; P = .014). Overall mortality was high; 34.2% of the cohort died at a median age of 42.5 years. HTLV-1 infection contributes to the risk of developing bronchiectasis and worsens outcomes among Indigenous Australians.

To quantify the burden of disease and injury for the Aboriginal and non-Aboriginal populations in the Northern Territory. Analysis of Northern Territory data for 1 January 1994 to 30 December 1998 from multiple sources. Disability-adjusted life-years (DALYs), by age, sex, cause and Aboriginality. Cardiovascular disease was the leading contributor (14.9%) to the total burden of disease and injury in the NT, followed by mental disorders (14.5%) and malignant neoplasms (11.2%). There was also a substantial contribution from unintentional injury (10.4%) and intentional injury (4.9%). Overall, the NT Aboriginal population had a rate of burden of disease 2.5 times higher than the non-Aboriginal population; in the 35-54-year age group their DALY rate was 4.1 times higher. The leading causes of disease burden were cardiovascular disease for both Aboriginal men (19.1%) and women (15.7%) and mental disorders for both non-Aboriginal men (16.7%) and women (22.3%). A comprehensive assessment of fatal and non-fatal conditions is important in describing differentials in health status of the NT population. Our study provides comparative data to identify health priorities and facilitate a more equitable distribution of health funding.

To describe the incidence and mortality of invasive infections in Indigenous children admitted to paediatric and general intensive care units (ICUs) in Australia. Retrospective multi-centre cohort study of Australian and New Zealand Paediatric Intensive Care Registry data. All children under 16 years of age admitted to an ICU in Australia, 1 January 2002 - 31 December 2013. Indigenous children were defined as those identified as Aboriginal and/or Torres Strait Islander in a mandatory admissions dataset. Population-based ICU mortality and admission rates. Invasive infections accounted for 23.0% of non-elective ICU admissions of Indigenous children (726 of 3150), resulting in an admission rate of 47.6 per 100 000 children per year. Staphylococcus aureus was the leading pathogen identified in children with sepsis/septic shock (incidence, 4.42 per 100 000 Indigenous children per year; 0.57 per 100 000 non-Indigenous children per year; incidence rate ratio 7.7; 95% CI, 5.8-10.1; P < 0.001). While crude and risk-adjusted ICU mortality related to invasive infections was not significantly different for Indigenous and non-Indigenous children (odds ratio, 0.75; 95% CI, 0.53-1.07; P = 0.12), the estimated population-based age-standardised mortality rate for invasive infections was significantly higher for Indigenous children (2.67 per 100 000 per year v 1.04 per 100 000 per year; crude incidence rate ratio, 2.65; 95% CI, 1.88-3.64; P < 0.001). The ICU admission rate for severe infections was several times higher for Indigenous than for non-Indigenous children, particularly for S. aureus infections. While ICU case fatality rates were similar, the population-based mortality was more than twice as high for Indigenous children. Our study highlights an important area of inequality in health care for Indigenous children in a high income country that needs urgent attention.

The Eastern Mediterranean Region (EMR) is witnessing an increase in chronic disorders, including mental illness. With ongoing unrest, this is expected to rise. This is the first study to quantify the burden of mental disorders in the EMR. We used data from the Global Burden of Disease study (GBD) 2013. DALYs (disability-adjusted life years) allow assessment of both premature mortality (years of life lost-YLLs) and nonfatal outcomes (years lived with disability-YLDs). DALYs are computed by adding YLLs and YLDs for each age-sex-country group. In 2013, mental disorders contributed to 5.6% of the total disease burden in the EMR (1894 DALYS/100,000 population): 2519 DALYS/100,000 (2590/100,000 males, 2426/100,000 females) in high-income countries, 1884 DALYS/100,000 (1618/100,000 males, 2157/100,000 females) in middle-income countries, 1607 DALYS/100,000 (1500/100,000 males, 1717/100,000 females) in low-income countries. Females had a greater proportion of burden due to mental disorders than did males of equivalent ages, except for those under 15 years of age. The highest proportion of DALYs occurred in the 25-49 age group, with a peak in the 35-39 years age group (5344 DALYs/100,000). The burden of mental disorders in EMR increased from 1726 DALYs/100,000 in 1990 to 1912 DALYs/100,000 in 2013 (10.8% increase). Within the mental disorders group in EMR, depressive disorders accounted for most DALYs, followed by anxiety disorders. Among EMR countries, Palestine had the largest burden of mental disorders. Nearly all EMR countries had a higher mental disorder burden compared to the global level. Our findings call for EMR ministries of health to increase provision of mental health services and to address the stigma of mental illness. Moreover, our results showing the accelerating burden of mental health are alarming as the region is seeing an increased level of instability. Indeed, mental health problems, if not properly addressed, will lead to an increased burden of diseases in the region.

To examine recent changes in the birth prevalence of cerebral palsy in Australia; to examine the functional mobility of children with cerebral palsy by residential remoteness.Population-based register study; analysis of Australian Cerebral Palsy Register (ACPR) data.Children with cerebral palsy born in Australia, 1995-2016, and included in the ACPR at the time of the most recent state/territory data provision (31 July 2022).Change in birth prevalence of cerebral palsy, of cerebral palsy acquired pre- or perinatally (in utero to day 28 after birth), both overall and by gestational age group (less than 28, 28-31, 32-36, 37 or more weeks), and of cerebral palsy acquired post-neonatally (day 29 to two years of age); gross motor function classification by residential remoteness.Data for 10 855 children with cerebral palsy born during 1995-2016 were available, 6258 of whom were boys (57.7%). The birth prevalence of cerebral palsy in the three states with complete case ascertainment (South Australia, Victoria, Western Australia) declined from 2.1 (95% confidence interval [CI], 1.9-2.4) cases per 1000 live births in 1995-1996 to 1.5 (95% CI, 1.3-1.7) cases per 1000 live births in 2015-2016. The birth prevalence of pre- or perinatally acquired cerebral palsy declined from 2.0 (95% CI, 1.7-2.3) to 1.4 (95% CI, 1.2-1.6) cases per 1000 live births; statistically significant declines were noted for all gestational ages except 32-36 weeks. The decline in birth prevalence of post-neonatally acquired cerebral palsy, from 0.15 (95% CI, 0.11-0.21) to 0.08 (95% CI, 0.05-0.12) cases per 1000 live births, was not statistically significant. Overall, 3.4% of children with cerebral palsy (307 children) lived in remote or very remote areas, a larger proportion than for all Australians (2.0%); the proportion of children in these areas who required wheelchairs for mobility was larger (31.3%) than that of children with cerebral palsy in major cities or regional areas (each 26.1%).The birth prevalence of cerebral palsy declined markedly in Australia during 1995-2016, reflecting the effects of advances in maternal and perinatal care. Our findings highlight the need to provide equitable, culturally safe access to antenatal services for women, and to health and disability services for people with cerebral palsy, across Australia.

Early detection of developmental difficulties is universally considered a necessary public health measure, with routine developmental monitoring an important function of primary healthcare services. This study aimed to describe the developmental monitoring practice in two remote Australian Aboriginal primary healthcare services and to identify gaps in the delivery of developmental monitoring services. A cross-sectional baseline medical record audit of all resident children aged less than 5 years in two remote Aboriginal health centres in the Northern Territory (NT) in Australia was undertaken between December 2010 and November 2011. A total of 151 medical records were audited, 80 in Community A and 71 in Community B. Developmental checks were more likely among children who attended services more regularly. In Community A, 63 (79%) medical records had some evidence of a developmental check and in Community B there were 42 (59%) medical records with such evidence. However, there was little indication of how assessments were undertaken: only one record noted the use of a formal developmental screening measure. In Community A, 16 (16%) records documented parent report and 20 (20%) documented staff observations, while in Community B, the numbers were 2 (3%) and 11 (19%), respectively. The overall recorded prevalence of developmental difficulties was 21% in Community A and 6% in Community B. This is the first study to describe the quality of developmental monitoring practice in remote Australian Aboriginal health services. The audit findings suggest the need for a systems-wide approach to the delivery and recording of developmental monitoring services. This will require routine training of remote Aboriginal health workers and remote area nurses in developmental monitoring practice including the use of a culturally appropriate, structured developmental screening measure.

Invasive group A streptococcus (iGAS) disease is an important cause of mortality globally. The incidence of iGAS in Australia's tropical Northern Territory (NT) has been previously reported as 32.2/100 000 in Indigenous people for the period 1991-1996. We aimed to measure the incidence and severity of iGAS disease in the NT since this time. We collected demographic data for all GAS blood culture isolates over a 12-year period (1998-2009) from the three hospital laboratories serving the tropical NT. We then collected detailed clinical information from hospital records and databases for the subset of these patients who were admitted to Royal Darwin Hospital during 2005-2009. There were 295 confirmed cases of GAS bacteraemia over the study period, with a mean (SD) age of 42.1 (22.0) years, and 163 (55.0%) were male. The annual age-adjusted incidence was 15.2 (95% CI 13.4-16.9)/100 000 overall and 59.4 (95% CI 51.2-67.6) in Indigenous Australians. For 2005-2009, there were 123 cases with the most common focus of infection being skin/soft tissue [44 (35.6%)]; 29 patients (23.6%) required intensive care unit admission and 20 (16.3%) had streptococcal toxic shock syndrome. Antecedent sore throat or use of non-steroidal anti-inflammatory drugs was rare, but current or recent scabies, pyoderma and trauma were common. The incidence and severity of iGAS are high and increasing in tropical northern Australia, and urgent attention is needed to improve surveillance and the social determinants of health in this population. This study adds to emerging data suggesting increasing importance of iGAS in low- and middle-income settings globally.

Murray Valley encephalitis virus (MVEV) is the most serious of the endemic arboviruses in Australia. It was responsible for six known large outbreaks of encephalitis in south-eastern Australia in the 1900s, with the last comprising 58 cases in 1974. Since then MVEV clinical cases have been largely confined to the western and central parts of northern Australia. In 2011, high-level MVEV activity occurred in south-eastern Australia for the first time since 1974, accompanied by unusually heavy seasonal MVEV activity in northern Australia. This resulted in 17 confirmed cases of MVEV disease across Australia. Record wet season rainfall was recorded in many areas of Australia in the summer and autumn of 2011. This was associated with significant flooding and increased numbers of the mosquito vector and subsequent MVEV activity. This paper documents the outbreak and adds to our knowledge about disease outcomes, epidemiology of disease and the link between the MVEV activity and environmental factors. Clinical and demographic information from the 17 reported cases was obtained. Cases or family members were interviewed about their activities and location during the incubation period. In contrast to outbreaks prior to 2000, the majority of cases were non-Aboriginal adults, and almost half (40%) of the cases acquired MVEV outside their area of residence. All but two cases occurred in areas of known MVEV activity. This outbreak continues to reflect a change in the demographic pattern of human cases of encephalitic MVEV over the last 20 years. In northern Australia, this is associated with the increasing numbers of non-Aboriginal workers and tourists living and travelling in endemic and epidemic areas, and also identifies an association with activities that lead to high mosquito exposure. This outbreak demonstrates that there is an ongoing risk of MVEV encephalitis to the heavily populated areas of south-eastern Australia.