Aggregation of melanoma tumour site within Western Australian families.

BACKGROUND: Evidence is emerging that melanoma has distinct aetiologic pathways and subtypes, characterized by factors like anatomic site of the tumour. To explore genetic influences on anatomic subtypes, we examined the extent to which melanomas in first-degree relatives shared the same body site of occurrence. METHODS: Population-level linked data was used to identify the study population of over 1.5 million individuals born in Western Australia between 1945 and 2014, and their first-degree relatives. There were 1009 pairs of invasive tumours from 677 family pairs, each categorised by anatomic site. Greater than expected representation of site-concordant pairs would suggest the presence of genetic factors that predispose individuals to site-specific melanoma. RESULTS: Comparing observed versus expected totals, we observed a modest increase in site concordance for invasive head/neck and truncal tumours (P=0.02). A corresponding analysis including in situ tumours showed a similar concordance (P=0.05). No further evidence of concordance was observed when stratified by sex. CONCLUSION: In conclusion, modest evidence of aggregation was observed but with inconsistent patterns between sites. Results suggest that further investigation into the familial aggregation of melanoma by tumour site is warranted, with the inclusion of genetic data in order to disentangle the relative contributions of genetic and environmental factors.

Modelling respiratory syncytial virus age-specific risk of hospitalisation in term and preterm infants.

BACKGROUND: Respiratory syncytial virus (RSV) is the most common cause of acute lower respiratory infections in children worldwide. The highest incidence of severe disease is in the first 6 months of life, with infants born preterm at greatest risk for severe RSV infections. The licensure of new RSV therapeutics (a long-acting monoclonal antibody and a maternal vaccine) in Europe, USA, UK and most recently in Australia, has driven the need for strategic decision making on the implementation of RSV immunisation programs. Data driven approaches, considering the local RSV epidemiology, are critical to advise on the optimal use of these therapeutics for effective RSV control. METHODS: We developed a dynamic compartmental model of RSV transmission fitted to individually-linked population-based laboratory, perinatal and hospitalisation data for 2000-2012 from metropolitan Western Australia (WA), stratified by age and prior exposure. We account for the differential risk of RSV-hospitalisation in full-term and preterm infants (defined as < 37 weeks gestation). We formulated a function relating age, RSV exposure history, and preterm status to the risk of RSV-hospitalisation given infection. RESULTS: The age-to-risk function shows that risk of hospitalisation, given RSV infection, declines quickly in the first 12 months of life for all infants and is 2.6 times higher in preterm compared with term infants. The hospitalisation risk, given infection, declines to < 10% of the risk at birth by age 7 months for term infants and by 9 months for preterm infants. CONCLUSIONS: The dynamic model, using the age-to-risk function, characterises RSV epidemiology for metropolitan WA and can now be extended to predict the impact of prevention measures. The stratification of the model by preterm status will enable the comparative assessment of potential strategies in the extended model that target this RSV risk group relative to all-population approaches. Furthermore, the age-to-risk function developed in this work has wider relevance to the epidemiological characterisation of RSV.

A two-year retrospective cohort study investigating the occurrence and short-term outcomes of dog-bite injures in regional Western Australia.

BACKGROUND: Dog bite injuries are a preventable yet common cause of animal related hospitalisation. Dog bites in metropolitan areas have been well characterised however there is limited information regarding dog bites in regional areas. This study sought to describe the demographics, clinical presentation and short-term outcomes of patients presenting with dog bite related injuries to Broome Regional Hospital (BRH). METHODS: A retrospective cohort study examined all dog bite related injuries presenting to BRH Emergency Department (ED) between July 1st 2021 - June 30th 2023, with the terms "dog" AND "bitten OR bite" in ED triage note. Chart review was performed to extract demographics, clinical presentation and short-term outcomes of dog bite related injuries. RESULTS: After exclusions, 207 patients were identified during the 2-year study period; approximately four dog-bites per week. Median age was 32 (IQR: 32, range 1-97 years old) with 46 % of patients being female. Residents of the Kimberley represented 78 % of presentations for dog bites. Dogs that belonged to or were known to patients were involved in 74 % of cases. The lower limb below the knee (42 %) was most commonly bitten, followed by the distal upper limb (30.5 %) and then face (13 %). Most patients presented on the same-day (67 %), were treated with antibiotics (79 %) and 83 % were discharged on the day of presentation. There were 43 (23 %) patients who required repair in the ED or operating theatre. Thirty-three patients were admitted to BRH. Seven patients required transfer for subspecialty tertiary level care. CONCLUSION: Dog-bite trauma is common and consumes significant health resources associated with ED presentations, hospital admissions, theatre usage and transfer in severe cases. A multifaceted approach encompassing education, engineering, and enforcement is required to prevent dog bites.

The Changing Detection Rate of Respiratory Syncytial Virus in Adults in Western Australia between 2017 and 2023.

The incidence of respiratory syncytial virus (RSV) in adults is inadequately defined and the impact of SARS-CoV-2-related non-pharmaceutical interventions (NPIs) is underexplored. Using laboratory data, we described the detection rate of RSV in adults ≥16 years in Western Australia (WA) between 2017 and 2023. With the exception of 2020, RSV detections rose annually between 2017 and 2023, reaching 50.7 per 100,000 in 2023 (95% confidence interval [CI], 47.9-53.8). RSV testing expanded considerably across the study period, with the testing in 2023 more than five times the 2017 total. The detection rate was highest in adults ≥60 years between 2017 and 2019, particularly those ≥75 years. Following 2020, the detections in all age groups increased, with the highest detection rate in 2023 in those ≥75-years (199.5 per 100,000; 95% CI, 180.5-220). NPIs significantly impacted RSV seasonality; the preceding winter pattern was disrupted, resulting in an absent 2020 winter season and two major summer seasons in 2020/21 and 2021/22. The RSV season began to realign in 2022, reverting to a winter seasonal pattern in 2023 and the largest season in the study period. Ongoing surveillance will be required to understand the stability of these increases and to delineate the impact of new immunisation strategies.

COVID-19 outcomes in haemopoietic stem cell transplant recipients in Western Australia: the value of vaccination and antiviral therapy.

Coronavirus-19 (COVID-19) mortality rates among haemopoietic stem cell transplant (HSCT) patients are high, ranging between 20% and 40%. We prospectively evaluated the mortality outcomes of COVID-19 in Western Australian HSCT patients. A total of 32/492 (6.5%) HSCT recipients contracted COVID-19 during the study, of whom 30/32 (94%) developed mild or asymptomatic disease. Two allogeneic HSCT patients were hospitalised for severe COVID-19; one patient died. Stringent healthcare, social isolation practices, aggressive vaccination programmes and rapid access to COVID-19 antivirals may have promoted mild COVID-19 illness in Western Australian HSCT patients, resulting in one of the lowest COVID-19 mortality rates in HSCT recipients worldwide.

Characterization of invasive Group B Streptococcus isolates from Western Australian infants, 2004-2020.

Background. Invasive Group B Streptococcus (GBS; Streptococcus agalactiae) remains a leading cause of infant morbidity and mortality. Intrapartum antibiotic prophylaxis (IAP) has been implemented in many countries with a reduction in early-onset disease, but an effective vaccine may further reduce the disease burden. Candidate vaccines targeting capsular polysaccharides and surface proteins are now in clinical trials.Methods. Using whole-genome sequencing and phenotypic antimicrobial susceptibility testing, we characterized sterile-site GBS isolates recovered from Western Australian infants between 2004 and 2020. Characteristics were compared between three time periods: 2004-2008, 2009-2015 and 2016-2020.Results. A total of 135 isolates were identified. The proportion of serotype III (22.7 % in Period 1 to 47.9 % in Period 3, P=0.04) and clonal complex 17 (13.6-39.6 %, P=0.01) isolates increased over time. Overall coverage of vaccines currently being trialled was >95 %. No isolates were penicillin resistant (MIC>0.25 mg l-1), but 21.5 % of isolates had reduced penicillin susceptibility (MIC>0.12 mg l-1) and penicillin MIC increased significantly over time (P=0.04). Clindamycin resistance increased over time to 45.8 % in the latest period.Conclusions. Based on comprehensive characterization of invasive infant GBS in Western Australia, we found that coverage for leading capsular polysaccharide and surface protein vaccine candidates was high. The demonstrated changes in serotype and molecular type highlight the need for ongoing surveillance, particularly with regard to future GBS vaccination programmes. The reduced susceptibility to IAP agents over time should inform changes to antibiotic guidelines.

Epidemiology and assessment of Hepatitis B positive children in Western Australia.

AIM: To describe the characteristics of patients with chronic hepatitis B (CHB) presenting to a tertiary paediatric hospital in Perth, Western Australia. Review of implementation of previous follow-up recommendations for the cohort was also undertaken. METHOD: A retrospective data analysis of all individuals aged between 0 and 17 years presenting to the tertiary children's hospital who were hepatitis B surface antigen (HBsAg) positive over 8 years (2013-2020). Demographic features, clinical progress and follow up are described, including proportion transferred to adult services. RESULTS: Seventy-four patients were identified to have CHB; mean age at diagnosis 11 years; standard deviation 4 years; 41 (55%) male. Cultural and ethnolinguistic diversity was high; 74% (n = 55) were from refugee-like backgrounds. Many did not demonstrate English proficiency (23/40; 75%) and 7 (10%) Australian born including 4 patients who were Aboriginal. Most patients (58%) with CHB were in the hepatitis B e antigen-positive chronic infection phase with no intervention provided. Seventeen children had undergone liver ultrasonography and one underwent liver biopsy; none received antiviral treatment. Follow up was concerning; 28 (38%) had at least one clinic non-attendance, 24 (32%) lost to follow-up and interpreter utilisation was poorly documented. Thirty-nine (53%) were transferred to adult services with only 56% attending follow-up. CONCLUSION: CHB burden is higher in those from culturally and ethnolinguistically diverse backgrounds. There is a significant loss to follow-up and suboptimal transfer to adult services. Improved recall, education and referral processes are necessary to overcome language, socioeconomic and cultural barriers. Although childhood complications are infrequent, longitudinal monitoring is crucial to prevent long-term complications and adult morbidity.

The temporal association between adverse drug reactions and antirheumatic drugs utilisation in Western Australia: a retrospective study from real-world data (1995-2015).

BACKGROUND/OBJECTIVES: Adverse drug reactions (ADRs) can result in morbidity, mortality, and higher healthcare costs. Given the limited information available on ADRs associated with antirheumatic medications, this study aims to analyse and compare ADR reporting for these drugs in the pharmacovigilance datasets of Western Australia (WA) and the United States (US). METHODS: Therapeutic Goods Administration provided WA pharmacovigilance data of selected antirheumatic drugs to from 1995 to 2015. The proportional reporting ratio (PRR) for WA case reports was compared to corresponding USA pharmacovigilance data by assessing the disproportionality of each ADR. clinically significant or true ADRs were determined using the Evans 2001 criteria (n > 2, chi-square > 4, PRR > 2). RESULTS: A total of 232 reports were found in WA, mostly on sixty-nine women aged 45 to 69. Methotrexate, leflunomide, azathioprine, sulfasalazine, and infliximab had the highest reported ADRs, related to gastrointestinal disorders. Patients who used biological agents in WA had 2.7 times the likelihood of reporting true ADRs compared to conventional antirheumatic drugs. The ADR rates in the two datasets were comparable over the study period. CONCLUSIONS: The PRR values of ADRs were consistent between WA and US databases. Methotrexate and infliximab use were commonly associated with ADR reports in WA females, with incidence rates comparable to the US; while patients using biological agents were more likely to report true ADRs than those on conventional antirheumatic drugs in WA.

Long-term incidence, risk factors and complications for venous thromboembolism in patients with systemic lupus erythematosus.

AIM: To compare frequency, incidence rates (IR), risk factors and outcomes of a first venous thromboembolic event (VTE) between patients with systemic lupus erythematosus (SLE) and controls. METHODS: Using state-wide longitudinal hospital data from Western Australia (WA), we recorded venous thrombosis (VT) and pulmonary embolism (PE) in patients with SLE (n = 1854, median age 40, 86% female) and matched hospitalised controls (n = 12,107, median age 40 years, females 88.6%) in the period 1985-2015. Results presented are medians, frequency, IR per 1000 person years (PY) and odds, rate, or adjusted hazard ratios (OR/RR/a-HR) with 95% confidence intervals (CI). RESULTS: Patients with SLE had significantly higher odds (12.8 vs 3.3%; OR 4.26, CI 3.60-5.05) and IR for a first VTE (10.09 vs 1.52; RR 6.64; CI 5.56-7.79). Over the three study decades, the IR for PE declined in patients with SLE from 7.74 to 3.75/1000 PY (p < .01) with no changes observed for VT or in controls. VTE recurred more frequently in patients with SLE (24.1% vs 10.2 %) (p < .01). Antiphospholipid antibodies (aPL) (a-HR 4.24, CI 2.50-7.19), serositis (a-HR 2.70, CI 1.86-3.91), lupus nephritis (a-HR 1.75 CI 1.25-2.33) and thrombocytopenia (a-HR 1.65 (1.10-2.49) were the strongest disease risk factors for VTE only in patients with SLE, while arterial hypertension, smoking and obesity were independent VTE risk factors for both groups. VTE was not associated with an increased risk for arterial events, but PE increased the risk for pulmonary hypertension (PH) in both patients with SLE (a-HR 6.47, CI 3.73-11.23) and controls (a-HR 9.09, CI 3.50-23.63). VTE increased the risk of death in both patients with SLE (a-HR 2.02, CI 1.50-2.70) and controls (a-HR 6.63, CI 5.21-8.42) after 10 years of follow-up. CONCLUSIONS: VTE affected 12.8% of patients with SLE at six times the VTE rate in controls with aPL as the strongest, but not the only risk factor in SLE. The risk of PH was increased in both groups following PE, but VTE did not associate with an increased risk of arterial events.

Utilising organs from hepatitis C virus PCR-positive donors in Western Australia.

We transplanted six solid organs from three hepatitis C virus (HCV) polymerase chain reaction (PCR)-positive donors during 2018-2023. Recipients were treated with glecaprevir/pibrentasvir or sofosbuvir/velpatasvir for 4-12 weeks, with all six achieving sustained virological response without significant adverse events. As occurs in other jurisdictions, solid organ transplants from HCR PCR-positive donors can be safely utilised in Australia.

A multicentre case series of analytically confirmed gamma-hydroxybutyrate intoxications in Western Australian emergency departments: Pre-hospital circumstances, co-detections and clinical outcomes.

INTRODUCTION: Gamma-hydroxybutyrate (GHB) use is associated with high risk of accidental overdose. This study examined the pre-hospital circumstances, demographic characteristics and clinical outcomes of analytically confirmed GHB emergency department (ED) presentations in Western Australia (WA). METHODS: This case series was conducted across three WA EDs involved in the Emerging Drugs Network of Australia, from April 2020 to July 2022. Patient demographics, pre-hospital drug exposure circumstances and ED presentation and outcome characteristics were collected from ambulance and hospital medical records of GHB-confirmed cases. RESULTS: GHB was detected in 45 ED presentations. The median age was 34 years and 53.3% (n = 24) were female. Most patients arrived at the ED by ambulance (n = 37, 85.7%) and required immediate emergency care (Australasian Triage Score 1 or 2 = 97.8%). One-third of patients were admitted to intensive care (n = 14, 31.1%). Methylamphetamine was co-detected in 37 (82.2%) GHB-confirmed cases. Reduced conscious state was indicated by first recorded Glasgow Coma Scale of ≤8 (n = 29, 64.4%) and observations of patients becoming, or being found, 'unresponsive' and 'unconscious' in various pre-hospital settings (n = 28, 62.2%). 'Agitated' and/or 'erratic' mental state and behavioural observations were recorded in 20 (44.4%) cases. DISCUSSION AND CONCLUSIONS: Analytically verified data from ED presentations with acute toxicity provides an objective information source on drug use trends and emerging public health threats. In our study, patients presenting to WA EDs with GHB intoxication were acutely unwell, often requiring intensive care treatment. The unexpectedly high proportion of female GHB intoxications and methylamphetamine co-ingestion warrants further exploration.

Prevalence of functional limitations in older remote-living Aboriginal Australians.

INTRODUCTION: To better tailor prevention and care strategies, there is a need to identify modifiable factors associated with functional impairment in older Aboriginal people, and related service needs. OBJECTIVE: To investigate the prevalence and associated factors for functional impairment in older Aboriginal people, and related service needs. DESIGN: Cross-sectional survey of 289 Aboriginal people aged ≥45 years living in the remote Kimberley region of Western Australia. Factors associated with functional impairment were explored with logistic regression. FINDINGS: 41.2% (95% CI 35.6%-47.0%) of participants required assistance with at least one I/ADL, and 26.0% (95% CI 21.2%-31.3%) required assistance with two or more I/ADLs. A core activity limitation (required assistance with showering, dressing or cooking) was reported by 15.9% (95% CI 12.1%-20.6%). In multivariable logistic regression analyses, older age, diabetes, difficulty walking, head injury, higher depression score and worse cognition were associated with needing help with two or more I/ADLs, while older age, history of stroke, higher depression score and worse cognition were associated with the presence of a core activity limitation. The proportion of participants receiving support with I/ADLs ranged from 71.2% to 97.6%. Support was generally provided by family and friends rather than service providers. DISCUSSION: The key modifiable factors associated with functional impairment in older Aboriginal people living in remote regions are diabetes, depression and cognitive impairment. Services required are transport and socio-cultural activities, and ensuring support for family providing the majority of care. CONCLUSIONS: This study highlights the need for holistic prevention strategies and care for older Aboriginal people with functional limitations and their families.

Cancer Risk and Mortality in Hospitalized Patients With Idiopathic Inflammatory Myopathies in Western Australia.

OBJECTIVE: To compare cancer incidence, type, and survival between patients with idiopathic inflammatory myopathies (IIMs) in Western Australia (WA) and the general population. METHODS: Administrative health data for hospitalized patients with incident IIM (n = 803, 56.5% female, median age 62.0 yrs), classified by a validated algorithm as polymyositis (PM; 36.2%), dermatomyositis (DM; 27.4%), inclusion body myositis (IBM; 17.1%), overlap myositis (OM; 10.7%), and other IIM (8.6%), were linked to WA cancer and death registries for the period of 1980 to 2014. Cancer incidence rates (CIRs) before and after IIM diagnosis as well as cancer mortality were compared with age-, sex-, and calendar year-matched controls (n = 3225, 54.9% female, median age 64 yrs) by rate ratios (RRs) and Kaplan-Meier survival estimates. RESULTS: The prediagnosis CIR was similar for patients with IIM and controls (6.57 vs 5.95; RR 1.11, 95% CI 0.88-1.39) and for patients evolving to DM (n = 220) or other IIM subtypes (6.59 vs 6.56; RR 1.01, 95% CI 0.38-3.69). During follow-up, CIR was higher for all DM (4.05, 95% CI 3.04-5.29), with increased CIR for lung cancer vs controls (1.05 vs 0.33; RR 3.18, 95% CI 1.71-5.47). Cancer post diagnosis shortened life span by 59 months for patients with IIM (103 vs 162 months, P < 0.01), but reduced survival rates were observed only in patients with DM and IBM. CONCLUSION: Cancer risk was not increased prior to IIM, but CIR for lung cancer was increased following DM diagnosis. As cancer reduced survival only in patients with DM and IBM, these data support a strategy of limited cancer screening in IIM.

Psychiatric disorders in childhood cancer survivors: A retrospective matched cohort study of inpatient hospitalisations and community-based mental health services utilisation in Western Australia.

OBJECTIVE: We examined the impact of long-term mental health outcomes on healthcare services utilisation among childhood cancer survivors in Western Australia using linked hospitalisations and community-based mental healthcare records from 1987 to 2019. METHOD: The study cohort included 2977 childhood cancer survivors diagnosed with cancer at age < 18 years in Western Australia from 1982 to 2014 and a matched non-cancer control group of 24,994 individuals. Adjusted hazard ratios of recurrent events were estimated using the Andersen-Gill model. The cumulative burden of events over time was assessed using the method of mean cumulative count. The annual percentage change in events was estimated using the negative binomial regression model. RESULTS: The results showed higher community-based service contacts (rate/100 person-years: 30.2, 95% confidence interval = [29.7-30.7] vs 22.8, 95% confidence interval = [22.6-22.9]) and hospitalisations (rate/1000 person-years: 14.8, 95% confidence interval = [13.6-16.0] vs 12.7, 95% confidence interval = [12.3-13.1]) in childhood cancer survivors compared to the control group. Childhood cancer survivors had a significantly higher risk of any event (adjusted hazard ratio = 1.5, 95% confidence interval = [1.1-2.0]). The cumulative burden of events increased with time since diagnosis and across age groups. The annual percentage change for hospitalisations and service contacts significantly increased over time (p < 0.05). Substance abuse was the leading cause of hospitalisations, while mood/affective and anxiety disorders were common causes of service contacts. Risk factors associated with increased service events included cancer diagnosis at age < 5 years, leukaemia diagnosis, high socioeconomic deprivation, and an attained age of < 18 years. CONCLUSIONS: The elevated utilisation of healthcare services observed among childhood cancer survivors emphasises the need for periodic assessment of psychiatric disorders, particularly in high-risk survivors, to facilitate early management and optimise healthcare resources.

The effects of pre-eclampsia on social and emotional developmental vulnerability in children at age five in Western Australia: A population data linkage study.

BACKGROUND: It is important to explore factors that may hinder early childhood development in AEDC Emotional Maturity and Social Competence domains as these underpin the foundation for health, well-being, and productivity over the life course. No previous study has examined whether, or to what extent, preeclampsia increases the risk of developmental vulnerability in social and emotional domains in early childhood. METHODS: We conducted a retrospective population-based cohort study on the association between preeclampsia and childhood developmental vulnerability in emotional maturity and social competence domains in children born in Western Australia in 2009, 2012 and 2015. We obtained records of births, developmental anomalies, midwives notifications and hospitalisations. These data were linked to the Australian Early Development Census (AEDC), from which developmental vulnerability in emotional maturity and social competence domains at a median age of 5 years was ascertained. Causal relative risks (RR) were estimated with doubly robust estimation. RESULTS: A total of 64,391 mother-offspring pairs were included in the final analysis. For the whole cohort, approximately 25 % and 23 % of children were classified as developmentally vulnerable or at-risk on AEDC emotional maturity and social competence domains, respectively. Approximately 2.8 % of children were exposed in utero to preeclampsia. Children exposed to preeclampsia were more likely to be classified as developmentally vulnerable or at-risk on the emotional maturity (RR = 1.19, 95%CI:1.11-1.28) and social competence domains (RR = 1.22, 95 % CI:1.13-1.31). CONCLUSION: Children exposed to pre-eclampsia in utero were more likely to be developmentally vulnerable in emotional maturity and social competence domains in this cohort. Our findings provide new insights into the harmful effect of preeclampsia on childhood developmental vulnerability.

Surveillance for lumpy skin disease and foot and mouth disease in the Kimberley, Western Australia.

We quantified the sensitivity of surveillance for lumpy skin disease (LSD) and foot and mouth disease (FMD) in cattle in the Kimberley region of Western Australia. We monitored producer and veterinary activity with cattle for 3 years commencing January 2020. Each year, ~274,000 cattle of 685,540 present on 92 pastoral leases (stations) were consigned to other stations, live export or slaughter. Veterinarians examined 103,000 cattle on the stations, 177,000 prior to live export, and 10,000 prior to slaughter. Detection probabilities for the disease prior to transport or during veterinary procedures and inspections were elicited by survey of 17 veterinarians working in Northern Australia. The veterinarians estimated the probabilities that they would notice, recognise, and submit samples from clinical cases of LSD and FMD, given a 5% prevalence of clinical signs in the herd. We used scenario tree methodology to estimate monthly surveillance sensitivity of observations made by producers and by veterinarians during herd management visits, pre-export inspections, and ante-mortem inspections. Average monthly combined sensitivities were 0.49 for FMD and 0.37 for LSD. Sensitivity was high for both diseases during the dry season and low in the wet season. We estimated the confidence in freedom from the estimated surveillance sensitivity given one hypothetically infected herd, estimated probability of introduction, and prior confidence in freedom. This study provided assurance that the Kimberley is free of these diseases and that routine producer and veterinary interactions with cattle are adequate for the timely detection of the disease should they be introduced.

Evaluation of the accuracy of diagnostic coding and clinical documentation for traumatic heterotopic ossification diagnoses in Western Australian hospitals.

BACKGROUND: Traumatic heterotopic ossification (tHO) refers to the pathological formation of ectopic bone in soft tissues that can occur following burn, neurological ororthopaedic trauma. As completeness and accuracy of medical diagnostic coding can vary based on coding practices and depend on the institutional culture of clinical documentation, it is important to assess diagnostic coding in that local context. To the authors' knowledge, there is no prior study evaluating the accuracy of medical diagnostic coding or specificity of clinical documentation for tHO diagnoses across Western Australia (WA) trauma centres or across the full range of inciting injury and surgical events. OBJECTIVE: To evaluate and compare the clinical documentation and the diagnostic accuracy of ICD-10-AM coding for tHO in trauma populations across 4 WA hospitals. METHODS: A retrospective data search of the WA trauma database was conducted to identify patients with tHO admitted to WA hospitals following burn, neurological or orthopaedic trauma. Patient demographic and tHO diagnostic characteristics were assessed for all inpatient and outpatient tHO diagnoses. The frequency and distribution of M61 (HO-specific) and broader, musculoskeletal (non-specific) ICD-10-AM codes were evaluated for tHO cases in each trauma population. RESULTS: HO-specific M61 ICD-10-AM codes failed to identify more than a third of true tHO cases, with a high prevalence of non-specific HO codes (19.4 %) and cases identified via manual chart review (25.4 %). The sensitivity of M61 codes for correctly diagnosing tHO after burn injury was 50 %. ROC analysis showed that M61 ICD-10-AM codes as a predictor of a true positive tHO diagnosis were a less than favourable method (AUC=0.731, 95 % CI=0.561-0.902, p = 0.012). Marked variability in clinical documentation for tHO was identified across the hospital network. CONCLUSION: Coding inaccuracies may, in part, be influenced by insufficiencies in clinical documentation for tHO diagnoses, which may have implications for future research and patient care. Clinicians should consistently employ standardised clinical terminology from the point of care to increase the likelihood of accurate medical diagnostic coding for tHO diagnoses.

Obstetric and Neonatal Invasive Meningococcal Disease Caused by Neisseria meningitidis Serogroup W, Western Australia, Australia.

Three mother-baby pairs with invasive meningococcal disease occurred over 7 months in Western Australia, Australia, at a time when serogroup W sequence type 11 clonal complex was the predominant local strain. One mother and 2 neonates died, highlighting the role of this strain as a cause of obstetric and early neonatal death.

Impact of Meningococcal ACWY Vaccination Program during 2017-18 Epidemic, Western Australia, Australia.

The rising incidence of invasive meningococcal disease (IMD) caused by Neisseria meningitidis serogroup W in Western Australia, Australia, presents challenges for prevention. We assessed the effects of a quadrivalent meningococcal vaccination program using 2012-2020 IMD notification data. Notification rates peaked at 1.8/100,000 population in 2017; rates among Aboriginal and Torres Strait Islander populations were 7 times higher than for other populations. Serogroup W disease exhibited atypical manifestations and increased severity. Of 216 cases, 20 IMD-related deaths occurred; most (19/20) were in unvaccinated persons. After the 2017-2018 targeted vaccination program, notification rates decreased from 1.6/100,000 population in 2018 to 0.9/100,000 population in 2019 and continued to decline in 2020. Vaccine effectiveness (in the 1-4 years age group) using the screening method was 93.6% (95% CI 50.1%-99.2%) in 2018 and 92.5% (95% CI 28.2%-99.2%) in 2019. Strategic planning and prompt implementation of targeted vaccination programs effectively reduce IMD.