Contemporary Incidence and Prevalence of Rheumatic Fever and Rheumatic Heart Disease in Australia Using Linked Data: The Case for Policy Change

Incidence of Discharge Against Medical Advice in Queensland Hospital Emergency Departments Among Indigenous Patients from 2016 to 2021

BACKGROUND

The incidence of discharge against medical advice (DAMA) in emergency departments (EDs) among Indigenous people is a growing concern in Australia. This study aimed to determine the incidence of ED DAMA in public hospitals in Queensland (QLD) from 2016 to 2021 and investigate the disparities in ED DAMA between Indigenous and non-Indigenous patients. The study also assessed the impact of the COVID-19 pandemic on the incidence of ED DAMA.

METHODS

A descriptive epidemiological study was conducted using aggregated data from QLD public hospital EDs. The data was retrieved from Clinical Excellence QLD, Healthcare Improvement Unit, in the QLD Health Open Data Portal for the period 1 January 2016 to 31 December 2021. Incidence rates and unadjusted odds ratios were calculated and compared using the chi-square test to identify differences between Indigenous and non-Indigenous patients.

RESULTS

The annual incidence of DAMA in EDs was 7.7% among Indigenous patients, compared to 4.8% among non-Indigenous patients, with the highest rate (8.9%) reported in 2021 among Indigenous patients. The incidence of ED DAMA was higher for Indigenous patients in major cities (20.0%) than in very remote areas (7.4%). Patients in triage categories 4 (10.0%) and 3 (7.3%) accounted for the vast majority of ED DAMA events among Indigenous patients. The acute group A hospitals had the highest incidence of ED DAMA (10.9% for Indigenous patients and 6.5% for non-Indigenous patients). The COVID-19 pandemic had no impact on the incidence of ED DAMA.

CONCLUSION

Indigenous patients experience a disparity in ED DAMA incidence. Addressing this issue requires collaborative efforts from healthcare providers, policymakers, and community organizations.

The heart of the matter: a re-iteration of the role of the social determinants of health in addressing health inequity in Central Australia

The persisting life-expectancy 'gap' between First Nations and non-First Nations Australians is fundamentally driven by the social determinants of health. These include income and social protection, access to adequate housing and food security, among others. These factors are particularly prominent in Central Australia. Inadequate housing has led to some of the highest rates of Streptococcus pyogenes infection in the world, which in turn drives an extremely high prevalence of rheumatic heart disease. Food insecurity and inadequate social protection manifesting as energy insecurity result in inadequate nutrition and have resulted in a huge burden of diabetes in Central Australia. These factors, combined with social exclusion, racism and the pervasive effect of colonisation, also drive a high rate of alcohol misuse. Only by prioritising equity in these 'social determinants' and emphasising the importance of First Nations leadership in formulating and implementing solutions will health inequity be addressed.

Demystifying environmental health-related diseases: Using ICD codes to facilitate environmental health clinical referrals

Background: The burden of disease of Aboriginal and Torres Strait Islander people is estimated as 2.3 times that of the broader Australian population, with between 30% and 50% of health inequalities attributable to poor environmental health. Objective: Although many Australian states and territories have clinical policy initiatives that seek to reduce the burden of preventable disease in this population, including field-based environmental health clinical referrals (EHCRs), there is little consistency across the jurisdictions, resulting in less potential to break the cycle of recurrent diseases within the home environment. Method and Results: This study addresses this inconsistency by recommending recognition and categorisation of environmental health risks to allow for accurate diagnosis and comparability across health services and locations by using the International Statistical Classification of Diseases and Related Health Problems (ICD) system, already in use in hospitals. Conclusion and Implications: Developing a list of mutually agreed environmental health attributable diseases for the EHCR process using assigned ICD-10-AM codes would influence the provision of primary care to include recognition of the impact of environmental health conditions and allow environmental health staff to provide a response and education at both community and household levels to break disease cycles.

Scabies: a clinical update

Scabies is the most common neglected tropical disease with cutaneous manifestations, disproportionately affecting socially disadvantaged populations living in overcrowded settings. Scabies infestation is characterised by a generalised intractable pruritus, and is often complicated by secondary bacterial infection, which can lead to a range of complications. Scabies is a clinical diagnosis and requires an adequate degree of suspicion. The use of dermoscopy may improve diagnostic accuracy. In Australia, the first-line treatment recommended for scabies is topical permethrin 5% cream, applied to the whole body and repeated in one week. Oral ivermectin is subsidised by the Pharmaceutical Benefits Scheme with streamlined authority for patients who have completed and failed treatment with topical therapy, have a contraindication to topical treatment or have crusted scabies. Early identification and prompt initiation of treatment is key to minimise the disease burden of scabies.

Risk Factors for Acute Rheumatic Disease: Exploring Factors at Individual and Collective Levels

Acute rheumatic fever (ARF) is a complex disease with several clinical manifestations. Its most significant long-term complication is valvular heart damage, commonly referred to as chronic rheumatic heart disease. The risk of ARF varies globally, with over 80% of cases occurring in low- and middle-income countries, highlighting the role of socioeconomic factors. A comprehensive understanding of the risk factors associated with ARF and its clinical, genetic, and sociodemographic mediators can help clinicians identify high-risk individuals, develop effective management strategies, enhance target screening and active case-finding initiatives, and ultimately improve patient outcomes. This review aimed to provide an overview of ARF and its global burden, focusing on the established and potential risk factors associated with its development.

NEARER SCAN (LENO BESIK) evaluation of a task-sharing echocardiographic active case finding programme for rheumatic heart disease in Australia and Timor-Leste: protocol for a hybrid type II effectiveness-implementation study

INTRODUCTION

Rheumatic heart disease (RHD) is underdiagnosed globally resulting in missed treatment opportunities and adverse clinical outcomes. We describe the protocol for a study which aims to co-design, implement and conduct an evaluation of a task-sharing approach to echocardiographic active case finding for early detection and management of RHD in high-risk settings in Australia and Timor-Leste.

METHODS AND ANALYSIS

Echocardiograms will be obtained by trained local staff using hand-held echocardiographic devices employing the 'Single Parasternal Long Axis view with a Sweep of the Heart' (SPLASH) technique and interpreted by experts remote from the site of acquisition. Approximately 1500 children and pregnant women will be screened across high-risk communities in Australia and Timor-Leste over an 18-month period. The study will use a type II effectiveness-implementation hybrid design. A tailored package of implementation strategies will be co-designed with communities and health services and mapped onto a Theory of Change framework. The clinical effectiveness will be assessed as the change in the proportion of the target population that are prescribed secondary prophylaxis for RHD by the end of the study compared with baseline. The implementation will be assessed as the adoption, penetration, sustainability, fidelity and cost of the programme with a mixed-methods theory-based and economic evaluation. Data will include numbers of normal, abnormal and uninterpretable SPLASH echocardiograms obtained, numbers of participants progressing through the cascade of care, interviews with staff and programme costs.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Human Research Ethics Committee of the NT Department of Health and Menzies School of Health Research, Darwin (HREC-2022-4479), the Western Australian Aboriginal Health Ethics Committee (HREC-1237) and the Instituto Nasional Saude Publika Timor-Leste Ethics and Technical Committee (03-UEPD/INSP-TL/V/2023). Informed consent is required to be enrolled. Study findings will be disseminated in the communities involved and submitted for publication.

TRIAL REGISTRATION NUMBER

NCT06002243.

Temporal changes in characteristics, incidence, and mortality in patients undergoing surgical intervention for mitral stenosis

To examine temporal changes in patient characteristics, the incidence rate of surgical intervention, and the three-year mortality rate for patients undergoing surgical intervention for mitral valve stenosis (MS) from 2001 to 2021 in Denmark. Utilizing Danish nationwide registries, we identified all adult patients undergoing first-time surgical intervention for MS (2001-2021). Temporal changes in the incidence rate of surgical intervention across calendar periods were investigated (2001-2005, 2006-2010, 2011-2015, and 2016-2021). Using Kaplan-Meier estimates, we computed temporal changes in three-year all-cause mortality across calendar periods. With multivariable Cox regression analysis, we assessed the adjusted rates of mortality. We included 256 patients (median age 60.3 years, 31.3% males). A stepwise decrease in the burden of chronic heart failure was identified (2001-2005: 54%, and 2016-2021: 20%, p-value < 0.001 for trend), while the burden of atrial fibrillation seemed stable (2001-2005: 51%, and 2016-2021: 46%, p-value = 0.27 for trend). The proportion of patients with rheumatic MS was 64% in 2001-2005 and 33% in 2016-2021, p-value < 0.001 for trend. 28 patients (10.9%) had mitral valve surgery prior to the first-time surgical intervention for MS. A stepwise decrease in the incidence rate of surgical intervention was observed: 3.3 cases per million person-years in 2001-2005 and 2.2 in 2016-2021. The incidence of patients diagnosed with first-time MS remained stable over calendar periods (2001-2005: 54.5 incidences per million person-years, and 2016-2021: 41.9, p-value = 0.46 for trend). The in-hospital mortality was 8.6% and the three-year mortality after surgical discharge was 9.0%, and we found no difference over calendar periods in either crude estimates or adjusted analysis. From nationwide data across three decades, we identified that the incidence of surgical interventiondecreased significantly within the past 20 years, while all-cause mortality remained stable. The burden of heart failure decreased, while the burden of atrial fibrillation remained stable over the study period.

Multimorbidity among the Indigenous population: A systematic review and meta-analysis

BACKGROUND

Multimorbidity, the concurrent presence of multiple chronic health conditions in an individual, represents a mounting public health challenge. Chronic illnesses are prevalent in the Indigenous populations, which contributes to multimorbidity. However, the epidemiology of multimorbidity in this population is not well studied. This review aimed to elucidate the extent, determinants, consequences, and prevention of multimorbidity within Indigenous populations globally, contrasting findings with non-Indigenous populations.

METHODS

Adhering to the PRISMA guidelines, this systematic review assimilated peer-reviewed articles and grey literature, focusing on the prevalence, determinants, implications, and preventive strategies of multimorbidity in global Indigenous populations. Emphasis was given to original, English-language, full-text articles, excluding editorials, and conference abstracts.

FINDINGS

Of the 444 articles identified, 13 met the inclusion criteria. Five studies are from Australia, and the rest are from the USA, Canada, New Zealand, and India. The study indicated a higher multimorbidity prevalence among Indigenous populations, with consistent disparities observed across various age groups. Particularly, Indigenous individuals exhibited a 2-times higher likelihood of multimorbidity compared to non-Indigenous populations. Noteworthy findings underscored the elevated severity of certain comorbid conditions, especially strokes, within Indigenous groups, with further revelations highlighting their significant pairing with conditions such as heart diseases and diabetes.

INTERPRETATION

The findings affirm the elevated burden of multimorbidity among Indigenous populations. Prevalence and risk of developing multimorbidity are significantly higher in this population compared to their non-Indigenous counterparts. Future research should prioritize harmonized research methodologies, fostering insights into the multimorbidity landscape, and promoting strategies to address health disparities in Indigenous populations.

Intervention needs assessment in children with heart diseases presenting to Tibebe-Ghion Specialized Teaching Hospital, Bahir Dar, North West Ethiopia - Tip of the iceberg of the intervention gap in Low-and-middle-income Countries (LMICs)

BACKGROUND

Pediatric heart disease is becoming a major contributor to childhood mortality. Almost half of congenital heart defects require intervention, either surgical or trans-catheter. Rheumatic heart disease also remains a global health problem in Low-and-middle-income-countries (LMICs). Intervention timing depends on the natural course and hemodynamic significance of the lesion with an emphasis on earlier intervention to prevent the damage of volume or pressure load and hypoxia.

OBJECTIVE

describe the current unmet intervention need of children with heart diseases presenting to Bahir Dar University Tibebe-Ghion Specialized Teaching Hospital.

METHODS

This is a descriptive cross-sectional study involving three-hundred-seventy-six children (376) who had echocardiography-confirmed cardiac diseases over fifteen months from August 01, 2022, to October 30, 2023. Variables were analysed using IBM SPSS version 27 software.

RESULTS

Of the 376 children with heart diseases, 54% were boys. The mean (SD) age was 53 (58) months, the median (IQR) being 26 (5-96). Congenital heart defects (CHDs) account for 68% of pediatric heart diseases. 77% of CHDs were acyanotic. Isolated Ventricular septal defect (21%) is the most common acyanotic CHD followed by patent ductus arteriosus (13.2%). Tetralogy of Fallot is the most common cyanotic CHD (41%). Rheumatic heart disease is the most common acquired heart disease (76.9%). 89.4% (336) of children were eligible for intervention need assessment. 35.4% (119) of intervention-eligible children had delayed presentation. 79.8% (268) of intervention-eligible children need intervention at the current presentation. 61%(163) of children who need intervention had delayed intervention timing. 242/268 (90.3%) of children with intervention needs were candidates for surgery. Only 0.7% of children had intervention.

CONCLUSION

Our study illustrates the unmet intervention need for pediatric heart diseases our health facilities faced to achieve the 2030 Sustained-development-goal (SDG) target.

Housing Initiatives to Address Strep A Infections and Reduce RHD Risks in Remote Indigenous Communities in Australia

Group A Streptococcus (Strep A) skin infections (impetigo) can contribute to the development of acute rheumatic fever (ARF) and rheumatic heart disease (RHD). This is of particular concern for Indigenous residents of remote communities, where rates of ARF and RHD are much higher than their urban and non-Indigenous counterparts. There are three main potential Strep A transmission pathways: skin to skin, surface to skin, and transmission through the air (via droplets or aerosols). Despite a lack of scientific certainty, the physical environment may be modified to prevent Strep A transmission through environmental health initiatives in the home, identifying a strong role for housing. This research sought to provide an outline of identified household-level environmental health initiatives to reduce or interrupt Strep A transmission along each of these pathways. The identified initiatives addressed the ability to wash bodies and clothes, to increase social distancing through improving the livability of yard spaces, and to increase ventilation in the home. To assist with future pilots and evaluation, an interactive costing tool was developed against each of these initiatives. If introduced and evaluated to be effective, the environmental health initiatives are likely to also interrupt other hygiene-related infections.

Clinical profile of paediatric acute rheumatic fever and rheumatic heart disease in Western Australia: 1987 to 2020

AIM

To describe the clinical profile of acute rheumatic fever (ARF) presentations to paediatric cardiology tertiary services in Western Australia (WA).

METHODS

A retrospective clinical audit of individuals with confirmed ARF referred to the only paediatric tertiary cardiac service in WA (1 January 1987 to 31 December 2020). Comparisons between inpatient, outpatient, remote and non-remote groups were assessed.

RESULTS

Four hundred seventy-one episodes of ARF in 457 individuals (235 male; median age = 8 years) met clinical criteria. The majority were Aboriginal and Torres Strait Islander children (91.2%), with 62.1% living in remote areas. The number of ARF and rheumatic heart disease (RHD) diagnoses per year increased from 1987 to 2017 with notable peaks in 2013 and 2017. The average annual incidence of tertiary-referred ARF in WA of 4-15-year-olds from 1987 to 2020 was 4.96 per 100 000. ARF features included carditis (59.9%), chorea (31%), polyarthritis (30%) and polyarthralgia (24.2%). RHD was evident in 61.8% of cases and predominantly manifested as mitral regurgitation (55.7%). Thirty-four children (7.4%) with severe RHD underwent valvular surgery. 12% had at least one recurrent ARF episode. Remote individuals had more than double the rate of recurrence compared to non-remote individuals (P = 0.0058). Compared to non-remote episodes, remote presentations had less polyarthritis (P = 0.0022) but greater proportions of raised ESR (P = 0.01), ASOT titres (P = 0.0073), erythema marginatum (P = 0.0218) and severe RHD (P = 0.0133).

CONCLUSION

The high proportion of Aboriginal and Torres Strait Islander Australians affected by ARF/RHD in WA reflects the significant burden of disease within this population. Children from remote communities were more likely to present with concurrent severe RHD. Our study reinforces the persisting need to improve primary and secondary ARF initiatives in rural and remote communities.

"Give Me Five": The Case for 5 Days of Antibiotics as the Default Duration for Acute Respiratory Tract Infections

Acute respiratory tract infections (ARTIs) account for most antibiotic prescriptions in pediatrics. Although US guidelines continue to recommend ≥10 days antibiotics for common ARTIs, evidence suggests that 5-day courses can be safe and effective. Academic imprinting seems to play a major role in the continued use of prolonged antibiotic durations. In this report, we discuss the evidence supporting short antibiotic courses for group A streptococcal pharyngitis, acute otitis media, and acute bacterial rhinosinusitis. We discuss the basis for prolonged antibiotic course recommendations and recent literature investigating shorter courses. Prescribers in the United States should overcome academic imprinting and follow international trends to reduce antibiotic durations for common ARTIs, where 5 days is a safe and efficacious course when antibiotics are prescribed.

Follow-up echocardiographic changes in children and youth aged <25 years with latent rheumatic heart disease: A systematic review and meta-analysis of global data

OBJECTIVES

To estimate progression, regression and persistence rates for borderline and mild-definite latent RHD in children and youth diagnosed at age < 25 years.

METHODS

A review was conducted in accordance with Preferred Reporting Items for Systematic reviews and Meta-Analysis guidelines. Electronic databases were searched for latent RHD echocardiography follow-up studies which used World Heart Federation diagnostic criteria. A meta-analysis of outcomes was conducted for borderline and mild-definite disease subcategories.

RESULTS

Data for 1618 individuals from 12 studies were included. For borderline cases, 48.51% regressed (95%CI 45.10-51.93), 13.99% progressed (95%CI 9.72-18.25), and 38.61% had persistent (unchanged) disease at follow-up (95%CI 29.68-47.54). For mild-definite cases, 34.01% regressed (95%CI 28.88-39.15), 8.06% progressed (95%CI 3.65-16.90), and 60.23% had persistent disease (95%CI 55.08-67.38).

CONCLUSIONS

Borderline and mild-definite latent RHD show variable evolution following initial diagnosis. While 8% of mild-definite and 14% borderline cases had signs of disease progression at follow-up, a third of mild-definite and half of borderline cases had disease regression, even with sub adequate antibiotic prophylaxis. The significant variability between study cohorts suggests latent RHD natural history is likely variable between different endemic regions globally. Future research is needed to identify those individuals who would most benefit from antibiotic prophylaxis and determine regional natural history of latent RHD.

Morbidity and mortality outcomes of patients requiring isolated tricuspid valve surgery: a retrospective cohort study of 537 patients in New South Wales between 2002 and 2018

OBJECTIVES

The aim of the study was to evaluate mortality and morbidity outcomes following open-heart isolated tricuspid valve surgery (TVSx) with medium to long-term follow-up.

DESIGN

Retrospective cohort study.

SETTING

New South Wales public and private hospital admissions between 1 January 2002 and 30 June 2018.

PARTICIPANTS

A total of 537 patients underwent open isolated TVSx during the study period.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome was all-cause mortality tracked from the death registry to 31 December 2018. Secondary morbidity outcomes, including admission for congestive cardiac failure (CCF), new atrial fibrillation (AF), infective endocarditis (IE), pulmonary embolism (PE) and insertion of a permanent pacemaker (PPM) or implantable cardioverter-defibrillator (ICD), were tracked from the Admitted Patient Data Collection database. Independent mortality associations were determined using the Cox regression method.

RESULTS

A total of 537 patients underwent open isolated TVSx (46% male): median age (IQR) was 63.5 years (43.9-73.8 years) with median length of stay of 16 days (10-31 days). Main cardiovascular comorbidities were AF (54%) and CCF (42%); 67% had rheumatic tricuspid valve. In-hospital and total mortality were 7.4% and 39.3%, respectively (mean follow-up: 4.8 years). Cause-specific deaths were evenly split between cardiovascular and non-cardiovascular causes. Predictors of mortality included a history of CCF (HR=1.78, 95% CI 1.33 to 2.38, p<0.001) and chronic pulmonary disease (HR=2.66, 95% CI 1.63 to 4.33, p<0.001). In-hospital PPM rate was 10.0%. At 180 days, 53 (9.9%) patients were admitted for CCF, 25 (10.1%) had new AF, 7 (1.5%) had new IE and <1% had PE, post-discharge PPM or ICD insertion.

CONCLUSION

Open isolated TVSx carries significant mortality risk, with decompensated CCF and new AF the most common morbidities encountered after surgery. This report forms a benchmark to compare outcomes with newer percutaneous tricuspid interventions.

Eliminate all risks: A call to reexamine the link between canine scabies and rheumatic heart disease

Rheumatic heart disease (RHD) and acute rheumatic fever (ARF) disproportionately affect individuals in low-resource settings. ARF is attributed to an immune response to Group A Streptococcus (GAS) following GAS pharyngitis and potentially GAS impetigo in which infection can be initiated by scabies infestation. The burden of ARF and RHD in Aboriginal and Torres Strait Islander people in Australia is among the highest globally. Following recent calls to include dog management programs in ARF and RHD prevention programs, we believe it is timely to assess the evidence for this, particularly since previous recommendations excluded resources to prevent zoonotic canine scabies. While phylogenetic analyses have suggested that the Sarcoptes mite is host specific, they have differed in interpretation of the strength of their findings regarding species cross-over and the need for canine scabies control to prevent human itch. Given that there is also indication from case reports that canine scabies leads to human itch, we propose that further investigation of the potential burden of zoonotic canine scabies and intervention trials of canine scabies prevention on the incidence of impetigo are warranted. Considering the devastating impacts of ARF and RHD, evidence is required to support policy to eliminate all risk factors.

Adult-onset acute rheumatic fever with chorea and carditis

Rheumatic fever is a major cause of cardiovascular morbidity and mortality in low-income and middle-income countries, and it usually occurs at a young age. Adult-onset acute rheumatic fever is a rare condition and usually represents a recurrence of childhood-onset disease. We report a case of an elderly man presenting with rheumatic carditis and rheumatic chorea subsequently diagnosed with adult-onset rheumatic fever.

Strep A: challenges, opportunities, vaccine-based solutions, and economics

This collection of articles focuses on Streptococcus pyogenes (Strep A) vaccine research and innovation, with a focus on emerging efforts to understand and estimate the full societal value of Strep A vaccination.

Outcomes of possible and probable rheumatic fever: A cohort study using northern Australian register data, 2013-2019

In Australia, there is a high burden of acute rheumatic fever (ARF) among Aboriginal and Torres Strait Islander peoples. Clinical diagnostic criteria can result in a diagnosis of 'definite', 'probable' or 'possible' ARF and outcomes range from recovery to severe rheumatic heart disease (RHD). We compared outcomes by ARF diagnosis, where the main outcome was defined as disease progression from: possible to probable ARF, definite ARF or RHD; probable to definite ARF or RHD; or definite ARF to definite ARF recurrence or RHD. Data were extracted from the Northern Territory RHD register for Indigenous Australians with an initial diagnosis of ARF during the 5.5-year study period (01/01/2013-30/06/2019). Descriptive statistics were used to describe cohort characteristics, probability of survival, and cumulative incidence risk of disease progression. Cox proportional hazards regression was used to determine whether time to disease progression differed according to ARF diagnosis. Sub-analyses on RHD outcome, clinical manifestations, and antibiotic adherence were also performed. In total there were 913 cases with an initial ARF diagnosis. Of these, 92 (13%) experienced disease progression. The probability of disease progression significantly differed between ARF diagnoses (p = 0.0043; log rank test). Cumulative incidence risk of disease progression at 5.5 years was 33.6% (95% CI 23.6-46.2) for definite, 13.5% (95% CI 8.8-20.6) for probable and 11.4% (95% CI 6.0-21.3) for possible ARF. Disease progression was 2.19 times more likely in those with definite ARF than those with possible ARF (p = 0.026). Progression to RHD was reported in 52/732 (7%) of ARF cases with normal baseline echocardiography. There was a significantly higher risk of progression from no RHD to RHD if the initial diagnosis was definite compared to possible ARF (p<0.001). These data provide a useful way to stratify risk and guide prognosis for people diagnosed with ARF and can help inform practice.

Excess Deaths Associated with Rheumatic Heart Disease, Australia, 2013-2017

During 2013-2017, the mortality rate ratio for rheumatic heart disease among Indigenous versus non-Indigenous persons in Australia was 15.9, reflecting health inequity. Using excess mortality methods, we found that deaths associated with rheumatic heart disease among Indigenous Australians were probably substantially undercounted, affecting accuracy of calculations based solely on Australian Bureau of Statistics data.

Subcutaneous infusion of high-dose benzathine penicillin G is safe, tolerable, and suitable for less-frequent dosing for rheumatic heart disease secondary prophylaxis: a phase 1 open-label population pharmacokinetic study

Since 1955, the recommended strategy for rheumatic heart disease (RHD) secondary prophylaxis has been benzathine penicillin G [BPG; 1.2 MU (900 mg)] injections administered intramuscularly every 4 weeks. Due to dosing frequency, pain, and programmatic challenges, adherence is suboptimal. It has previously been demonstrated that BPG delivered subcutaneously at a standard dose is safe and tolerable and has favorable pharmacokinetics, setting the scene for improved regimens with less frequent administration. The safety, tolerability, and pharmacokinetics of subcutaneous infusions of high-dose BPG were assessed in 24 healthy adult volunteers assigned to receive either 3.6, 7.2, or 10.8 MU (three, six, and nine times the standard dose, respectively) as a single subcutaneous infusion. The delivery of the BPG to the subcutaneous tissue was confirmed with ultrasonography. Safety assessments, pain scores, and penicillin concentrations were measured for 16 weeks post-dose. Subcutaneous infusion of penicillin (SCIP) was generally well tolerated with all participants experiencing transient, mild infusion-site reactions. Prolonged elevated penicillin concentrations were described using a combined zero-order (44 days) and first-order (t1/2 = 12 days) absorption pharmacokinetic model. In simulations, time above the conventionally accepted target concentration of 20 ng/mL (0.02 µg/mL) was 57 days for 10.8 MU delivered by subcutaneous infusion every 13 weeks compared with 9 days of every 4-weekly dosing interval for the standard 1.2 MU intramuscular dose (i.e., 63% and 32% of the dosing interval, respectively). High-dose SCIP (BPG) is safe, has acceptable tolerability, and may be suitable for up to 3 monthly dosing intervals for secondary prophylaxis of RHD.

Research opportunities for the primordial prevention of rheumatic fever and rheumatic heart disease-streptococcal vaccine development: a national heart, lung and blood institute workshop report

Streptococcus pyogenes, also known as group A streptococcus (StrepA), is a bacterium that causes a range of human diseases, including pharyngitis, impetigo, invasive infections, and post-infection immune sequelae such as rheumatic fever and rheumatic heart disease. StrepA infections cause some of the highest burden of disease and death in mostly young populations in low-resource settings. Despite decades of effort, there is still no licensed StrepA vaccine, which if developed, could be a cost-effective way to reduce the incidence of disease. Several challenges, including technical and regulatory hurdles, safety concerns and a lack of investment have hindered StrepA vaccine development. Barriers to developing a StrepA vaccine must be overcome in the future by prioritising key areas of research including greater understanding of StrepA immunobiology and autoimmunity risk, better animal models that mimic human disease, expanding the StrepA vaccine pipeline and supporting vaccine clinical trials. The development of a StrepA vaccine is a complex and challenging process that requires significant resources and investment. Given the global burden of StrepA infections and the potential for a vaccine to save lives and livelihoods, StrepA vaccine development is an area of research that deserves considerable support. This report summarises the findings of the Primordial Prevention Working Group-VAX, which was convened in November 2021 by the National Heart, Lung, and Blood Institute. The focus of this report is to identify research gaps within the current StrepA vaccine landscape and find opportunities and develop priorities to promote the rapid and successful advancement of StrepA vaccines.

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.

The full health, economic, and social benefits of prospective Strep A vaccination

Recent research has documented a wide range of health, economic, and social benefits conferred by vaccination, beyond the direct reductions in morbidity, mortality, and future healthcare costs traditionally captured in economic evaluations. In this paper, we describe the societal benefits that would likely stem from widespread administration of safe and effective vaccines against Streptococcus pyogenes (Strep A), which was estimated to be the fifth-leading cause of infectious disease deaths globally prior to the COVID-19 pandemic. We then estimate the global societal gains from prospective Strep A vaccination through a value-per-statistical-life approach. Estimated aggregate lifetime benefits for 30 global birth cohorts range from $1.7 to $5.1 trillion, depending on the age at which vaccination is administered and other factors. These results suggest that the benefits of Strep A vaccination would be large and justify substantial investment in the vaccines' development, manufacture, and delivery.

Research priorities for the primordial prevention of acute rheumatic fever and rheumatic heart disease by modifying the social determinants of health

The social determinants of health (SDH), such as access to income, education, housing and healthcare, strongly shape the occurrence of acute rheumatic fever (ARF) and rheumatic heart disease (RHD) at the household, community and national levels. The SDH are systemic factors that privilege some more than others and result in poverty and inequitable access to resources to support health and well-being. Primordial prevention is the modification of SDH to improve health and reduce the risk of disease acquisition and the subsequent progression to RHD. Modifying these determinants using primordial prevention strategies can reduce the risk of exposure to Group A Streptococcus, a causative agent of throat and skin infections, thereby lowering the risk of initiating ARF and its subsequent progression to RHD.This report summarises the findings of the Primordial Prevention Working Group-SDH, which was convened in November 2021 by the National Heart, Lung, and Blood Institute to assess how SDH influence the risk of developing RHD. Working group members identified a series of knowledge gaps and proposed research priorities, while recognising that community engagement and partnerships with those with lived experience will be integral to the success of these activities. Specifically, members emphasised the need for: (1) global analysis of disease incidence, prevalence and SDH characteristics concurrently to inform policy and interventions, (2) global assessment of legacy primordial prevention programmes to help inform the co-design of interventions alongside affected communities, (3) research to develop, implement and evaluate scalable primordial prevention interventions in diverse settings and (4) research to improve access to and equity of services across the RHD continuum. Addressing SDH, through the implementation of primordial prevention strategies, could have broader implications, not only improving RHD-related health outcomes but also impacting other neglected diseases in low-resource settings.

Development and User Testing of a Dynamic Tool for Rheumatic Heart Disease Management

OBJECTIVE

Most rheumatic heart disease (RHD) registries are static and centralized, collecting epidemiological and clinical data without providing tools to improve care. We developed a dynamic cloud-based RHD case management application with the goal of improving care for patients with RHD in Uganda.

METHODS

The Active Community Case Management Tool (ACT) was designed to improve community-based case management for chronic disease, with RHD as the first test case. Global and local partner consultation informed selection of critical data fields and prioritization of application functionality. Multiple stages of review and revision culminated in user testing of the application at the Uganda Heart Institute.

RESULTS

Global and local partners provided feedback of the application via survey and interview. The application was well received, and top considerations included avenues to import existing patient data, considering a minimum data entry form, and performing a situation assessment to tailor ACT to the health system setup for each new country. Test users completed a postuse survey. Responses were favorable regarding ease of use, desire to use the application in regular practice, and ability of the application to improve RHD care in Uganda. Concerns included appropriate technical skills and supports and potential disruption of workflow.

CONCLUSION

Creating the ACT application was a dynamic process, incorporating iterative feedback from local and global partners. Results of the user testing will help refine and optimize the application. The ACT application showed potential for utility and integration into existing care models in Uganda.

Left ventricular remodelling in rheumatic heart disease - trends over time and implications for follow-up in childhood

BACKGROUND

Rheumatic heart disease (RHD) is the most common form of acquired heart disease worldwide. In RHD, volume loading from mitral regurgitation leads to left ventricular (LV) dilatation, increased wall stress, and ultimately LV dysfunction. Improved understanding of LV dynamics may contribute to refined timing of intervention. We aimed to characterize and compare left ventricular remodelling between rheumatic heart disease (RHD) severity groups by way of serial echocardiographic assessment of volumes and function in children.

METHODS

Children with RHD referred to Perth Children's Hospital (formally Princess Margaret Hospital) (1987-2020) were reviewed. Patients with longitudinal pre-operative echocardiograms at diagnosis, approximately 12 months and at most recent follow-up, were included and stratified into RHD severity groups. Left ventricular (LV) echocardiographic parameters were assessed. Adjusted linear mixed effect models were used to compare interval changes.

RESULTS

146 patients (median age 10 years, IQR 6-14 years) with available longitudinal echocardiograms were analysed. Eighty-five (58.2%) patients had mild, 33 (22.6%) moderate and 28 (19.2%) severe RHD at diagnosis. Mean duration of follow-up was 4.6 years from the initial diagnosis. Severe RHD patients had significantly increased end-systolic volumes (ESV) and end-diastolic volumes (EDV) compared to mild/moderate groups at diagnosis (severe versus mild EDV mean difference 27.05 ml/m2, p < 0.001, severe versus moderate EDV mean difference 14.95 ml/m2, p = 0.006). Mild and moderate groups experienced no significant progression of changes in volume measures. In severe RHD, LV dilatation worsened over time. All groups had preserved cardiac function.

CONCLUSIONS

In mild and moderate RHD, the lack of progression of valvular regurgitation and ventricular dimensions suggest a stable longer-term course. Significant LV remodelling occurred at baseline in severe RHD with progression of LV dilatation over time. LV function was preserved across all groups. Our findings may guide clinicians in deciding the frequency and timing of follow-up and may be of clinical utility during further reiterations of the Australia and New Zealand RHD Guidelines.

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.

Development of a sustained release implant of benzathine penicillin G for secondary prophylaxis of rheumatic heart disease

BACKGROUND

Regular intramuscular (i.m.) benzathine penicillin G (BPG) injections have been the cornerstone of rheumatic heart disease (RHD) secondary prophylaxis since the 1950s. Patient adherence to IM BPG is poor, largely due to pain, the need for regular injections every 3-4 weeks and health sector delivery challenges in resource-limited settings. There is an urgent need for new approaches for secondary prophylaxis, such as an implant which could provide sustained penicillin concentrations for more than 6 months.

METHODS

In this study we developed and evaluated a slow release implant with potential for substantially extended treatment. The side wall of a solid drug rich core was coated with polycaprolactone which acts as an impermeable barrier. The exposed surfaces at the ends of the implant defined the release surface area, and the in vitro release rate of drug was proportional to the exposed surface area across implants of differing diameter. The in vivo pharmacokinetics and tolerability of the implants were evaluated in a sheep model over 9 weeks after subcutaneous implantation.

RESULTS

The absolute release rates obtained for the poorly water-soluble benzathine salt were dependent on the exposed surface area demonstrating the impermeability of the wall of the implant. The implants were well-tolerated after subcutaneous implantation in a sheep model, without adverse effects at the implantation site. Gross structural integrity was maintained over the course of the study, with erosion limited to the dual-exposed ends. Steady release of penicillin G was observed over the 9 weeks and resulted in approximately constant plasma concentrations close to accepted target concentrations.

CONCLUSION

In principle, a long acting BPG implant is feasible as an alternative to IM injections for secondary prophylaxis of RHD. However, large implant size is currently a significant impediment to clinical utility and acceptability.

Rheumatic heart disease mortality in Indigenous and non-Indigenous Australians between 2010 and 2017

OBJECTIVES

To generate contemporary age-specific mortality rates for Indigenous and non-Indigenous Australians aged <65 years who died from rheumatic heart disease (RHD) between 2013 and 2017, and to ascertain the underlying causes of death (COD) of a prevalent RHD cohort aged <65 years who died during the same period.

METHODS

For this retrospective, cross-sectional epidemiological study, Australian RHD deaths for 2013-2017 were investigated by first, mortality rates generated using Australian Bureau of Statistics death registrations where RHD was a coded COD, and second COD analyses of death records for a prevalent RHD cohort identified from RHD register and hospitalisations. All analyses were undertaken by Indigenous status and age group (0-24, 25-44, 45-64 years).

RESULTS

Age-specific RHD mortality rates per 100 000 were 0.32, 2.63 and 7.41 among Indigenous 0-24, 25-44 and 45-64 year olds, respectively, and the age-standardised mortality ratio (Indigenous vs non-Indigenous 0-64 year olds) was 14.0. Within the prevalent cohort who died (n=726), RHD was the underlying COD in 15.0% of all deaths, increasing to 24.6% when RHD was included as associated COD. However, other cardiovascular and non-cardiovascular conditions were the underlying COD in 34% and 43% respectively.

CONCLUSION

Premature mortality in people with RHD aged <65 years has approximately halved in Australia since 1997-2005, most notably among younger Indigenous people. Mortality rates based solely on underlying COD potentially underestimates true RHD mortality burden. Further strategies are required to reduce the high Indigenous to non-Indigenous mortality rate disparity, in addition to optimising major comorbidities that contribute to non-RHD mortality.

Disease profiles in the Indigenous Australian population are suggestive of a common complement control haplotype

Aboriginal and Torres Strait Islander People (respectfully referred to as Indigenous Australians herein) are disparately burdened by many infectious and chronic diseases relative to Australians with European genetic ancestry. Some of these diseases are described in other populations to be influenced by the inherited profile of complement genes. These include complement factor B, H, I and complement factor H-related (CFHR) genes that can contribute to a polygenic complotype. Here the focus is on the combined deletion of CFHR1 and 3 to form a common haplotype (CFHR3-1Δ). The prevalence of CFHR3-1Δ is high in people with Nigerian and African American genetic ancestry and correlates to a higher frequency and severity of systemic lupus erythematosus (SLE) but a lower prevalence of age-related macular degeneration (AMD) and IgA-nephropathy (IgAN). This pattern of disease is similarly observed among Indigenous Australian communities. Additionally, the CFHR3-1Δ complotype is also associated with increased susceptibility to infection with pathogens, such as Neisseria meningitidis and Streptococcus pyogenes, which also have high incidences in Indigenous Australian communities. The prevalence of these diseases, while likely influenced by social, political, environmental and biological factors, including variants in other components of the complement system, may also be suggestive of the CFHR3-1Δ haplotype in Indigenous Australians. These data highlight a need to define the Indigenous Australian complotypes, which may lead to the discovery of new risk factors for common diseases and progress towards precision medicines for treating complement-associated diseases in Indigenous and non-Indigenous populations. Herein, the disease profiles suggestive of a common complement CFHR3-1Δ control haplotype are examined.

Surgery for rheumatic heart disease in the Northern Territory, Australia, 1997-2016: what have we gained?

BACKGROUND

Between 1964 and 1996, the 10-year survival of patients having valve replacement surgery for rheumatic heart disease (RHD) in the Northern Territory, Australia, was 68%. As medical care has evolved since then, this study aimed to determine whether there has been a corresponding improvement in survival.

METHODS

A retrospective study of Aboriginal patients with RHD in the Northern Territory, Australia, having their first valve surgery between 1997 and 2016. Survival was examined using Kaplan-Meier and Cox regression analysis.

FINDINGS

The cohort included 281 adults and 61 children. The median (IQR) age at first surgery was 31 (18-42) years; 173/342 (51%) had a valve replacement, 113/342 (33%) had a valve repair and 56/342 (16%) had a commissurotomy. There were 93/342 (27%) deaths during a median (IQR) follow-up of 8 (4-12) years. The overall 10-year survival was 70% (95% CI: 64% to 76%). It was 62% (95% CI: 53% to 70%) in those having valve replacement. There were 204/281 (73%) adults with at least 1 preoperative comorbidity. Preoperative comorbidity was associated with earlier death, the risk of death increasing with each comorbidity (HR: 1.3 (95% CI: 1.2 to 1.5), p<0.001). Preoperative chronic kidney disease (HR 6.5 (95% CI: 3.0 to 14.0) p≤0.001)), coronary artery disease (HR 3.3 (95% CI: 1.3 to 8.4) p=0.012) and pulmonary artery systolic pressure>50 mm Hg before surgery (HR 1.9 (95% CI: 1.2 to 3.1) p=0.007) were independently associated with death.

INTERPRETATION

Survival after valve replacement for RHD in this region of Australia has not improved. Although the patients were young, many had multiple comorbidities, which influenced long-term outcomes. The increasing prevalence of complex comorbidity in the region is a barrier to achieving optimal health outcomes.

Large Burden of Stroke Incidence in People with Cardiac Disease: A Linked Data Cohort Study

Purpose

People with cardiac disease have 2-4 times greater risk of stroke than the general population. We measured stroke incidence in people with coronary heart disease (CHD), atrial fibrillation (AF) or valvular heart disease (VHD).

Methods

We used a person-linked hospitalization/mortality dataset to identify all people hospitalized with CHD, AF or VHD (1985-2017), and stratified them as pre-existing (hospitalized 1985-2012 and alive at October 31, 2012) or new (first-ever cardiac hospitalization in the five-year study period, 2012-2017). We identified first-ever strokes occurring from 2012 to 2017 in patients aged 20-94 years and calculated age-specific and age-standardized rates (ASR) for each cardiac cohort.

Results

Of the 175,560 people in the cohort, most had CHD (69.9%); 16.3% had multiple cardiac conditions. From 2012-17, 5871 first-ever strokes occurred. ASRs were greater in females than males in single and multiple condition cardiac groups, largely driven by rates in females aged ≥75 years, with stroke incidence in this age group being at least 20% greater in females than males in each cardiac subgroup. In females aged 20-54 years, stroke incidence was 4.9-fold greater in those with multiple versus single cardiac conditions. This differential declined with increasing age. Non-fatal stroke incidence was greater than fatal stroke in all age groups except in the 85-94 age group. Incidence rate ratios were up to 2-fold larger in new versus pre-existing cardiac disease.

Conclusion

Stroke incidence in people with cardiac disease is substantial, with older females, and younger patients with multiple cardiac conditions, at elevated risk. These patients should be specifically targeted for evidence-based management to minimize the burden of stroke.

Transcatheter mitral valve-in-valve: treatment of rheumatic heart disease in young patients

BACKGROUND

Rheumatic heart disease (RHD) in young people presents a complex management problem. In Australia a significant proportion of those affected are Aboriginal and Torres Strait Islanders. Transcatheter mitral valve-in-valve (TMViV) replacement has emerged as an alternative to redo surgery in high-risk patients with degenerated mitral bioprostheses. The aim of this study is to review outcomes of TMViV replacement in young patients with RHD.

METHODS

A single-centre, retrospective review of prospectively collected data on patients undergoing TMViV from December 2017 to June 2021. Primary outcome was major adverse cardiovascular events. Secondary outcome was post-operative trans-thoracic echocardiogram (TTE) results.

RESULTS

There were seven patients with a mean age of 33 years and predominantly female (n = 5). Pre-operative comorbidities included diabetes (29%), chronic obstructive pulmonary disease (43%), left ventricular dysfunction (43%) and current smoking status (80%). Post-operative median length of hospital stay was 4 days with no post-operative renal failure, stroke, return to theatre, valve embolization or in hospital mortality. Post-operative TTE showed either nil or trivial central mitral regurgitation, no paravalvular leak and a median gradient of 5 mmHg (IQR 4.5, 7) across the new bioprosthesis; sustained at median follow-up of 22 months.

CONCLUSION

Current literature of TMViV replacement is focused on an older population with concurrent comorbidities. This study provides a unique insight into TMViV replacement in a young cohort of patients with complex social and geographical factors which sometimes prohibits the use of a mechanical valve. The prevalence of RHD remains high for Aboriginal and Torres Strait Islanders, planning for future repeat valve operations should be considered from the outset. We consider TMViV as a part of a staged procedural journey for young patients with RHD.

Evolution of non-fatal burden estimates for cardiovascular disease in Australia: a comparison of national and state-wide methodology of burden of disease

Objective Burden of disease studies measure the impact of disease at the population level;however, methods and data sources for estimates of prevalence vary. Using a selection of cardiovascular diseases, we aimed to describe the implications of using different disease models and linked administrative data on prevalence estimation within three Australian burden of disease studies. Methods Three different methods (A = 2011 Australian Burden of Disease Study; B = 2015 Australian Burden of Disease Study; C = 2015 Western Australian Burden of Disease Study), which used linked data, were used to compare prevalence estimates of stroke, aortic aneurysm, rheumatic valvular heart disease (VHD) and non-rheumatic VHD. We applied these methods to 2015 Western Australian data, and calculated crude overall and age-specific prevalence for each condition. Results Overall, Method C produced estimates of cardiovascular prevalence that were lower than the other methods, excluding non-rheumatic VHD. Prevalence of acute and chronic stroke was up to one-third higher in Method A and B compared to Method C. Aortic aneurysms had the largest change in prevalence, with Method A producing an eight-fold higher estimate compared to Method C, but Method B was 10-20% lower. Estimates of VHD varied dramatically, with an up to six-fold change in prevalence in Method C due to substantial changes to disease models and the use of linked data. Conclusions Prevalence estimates require the best available data sources, updated disease models and constant review to inform government policy and health reform. Availability of nation-wide linked data will markedly improve future burden estimates.

"The world is so white": improving cultural safety in healthcare systems for Australian Indigenous people with rheumatic heart disease

OBJECTIVE

To examine the views of senior health system knowledge holders, including Aboriginal experts, regarding the spaces where elimination strategies for rheumatic heart disease take place: Aboriginal and Torres Strait Islander ways of knowing, being and doing; and biomedical healthcare models. We aimed to support the implementation of the RHD Endgame Strategy by providing some of the 'how'.

METHODS

In-depth interviews were undertaken with 23 participants. The design of the interview questions and analysis of the data used strengths-based approaches as directed by Aboriginal researchers.

RESULTS

Given the dominance of the biomedical worldview, and the complex trajectory of RHD, there is significant tension in the intersection of worldviews. Tensions that limit productive dialogue are juxtaposed with suggestions on how to reduce tension through reflexivity, power shifting and endorsing Aboriginal leadership and governance. Evidence supported cultural safety for RHD care, prevention and elimination as the key action.

CONCLUSIONS

Recommendations include addressing power imbalances between dominant and minority populations throughout the health system; reform that both supports and is supported by Non-Indigenous and Aboriginal and Torres Strait Islander leadership.

IMPLICATIONS FOR PUBLIC HEALTH

Increased understanding of and support for Indigenous leadership and cultural safety will enable implementation of the new RHD strategy.

Standardization of Epidemiological Surveillance of Rheumatic Heart Disease

Rheumatic heart disease (RHD) is a long-term sequela of acute rheumatic fever (ARF), which classically begins after an untreated or undertreated infection caused by Streptococcus pyogenes (Strep A). RHD develops after the heart valves are permanently damaged due to ARF. RHD remains a leading cause of morbidity and mortality in young adults in resource-limited and low- and middle-income countries. This article presents case definitions for latent, suspected, and clinical RHD for persons with and without a history of ARF, and details case classifications, including differentiating between definite or borderline according to the 2012 World Heart Federation echocardiographic diagnostic criteria. This article also covers considerations specific to RHD surveillance methodology, including discussions on echocardiographic screening, where and how to conduct active or passive surveillance (eg, early childhood centers/schools, households, primary healthcare), participant eligibility, and the surveillance population. Additional considerations for RHD surveillance, including implications for secondary prophylaxis and follow-up, RHD registers, community engagement, and the negative impact of surveillance, are addressed. Finally, the core elements of case report forms for RHD, monitoring and audit requirements, quality control and assurance, and the ethics of conducting surveillance are discussed.

Evaluation of a Community-Led Program for Primordial and Primary Prevention of Rheumatic Fever in Remote Northern Australia

Environmental factors including household crowding and inadequate washing facilities underpin recurrent streptococcal infections in childhood that cause acute rheumatic fever (ARF) and subsequent rheumatic heart disease (RHD). No community-based 'primordial'-level interventions to reduce streptococcal infection and ARF rates have been reported from Australia previously. We conducted a study at three Australian Aboriginal communities aiming to reduce infections including skin sores and sore throats, usually caused by Group A Streptococci, and ARF. Data were collected for primary care diagnoses consistent with likely or potential streptococcal infection, relating to ARF or RHD or related to environmental living conditions. Rates of these diagnoses during a one-year Baseline Phase were compared with a three-year Activity Phase. Participants were children or adults receiving penicillin prophylaxis for ARF. Aboriginal community members were trained and employed to share knowledge about ARF prevention, support reporting and repairs of faulty health-hardware including showers and provide healthcare navigation for families focusing on skin sores, sore throat and ARF. We hypothesized that infection-related diagnoses would increase through greater recognition, then decrease. We enrolled 29 participants and their families. Overall infection-related diagnosis rates increased from Baseline (mean rate per-person-year 1.69 [95% CI 1.10-2.28]) to Year One (2.12 [95% CI 1.17-3.07]) then decreased (Year Three: 0.72 [95% CI 0.29-1.15]) but this was not statistically significant (p = 0.064). Annual numbers of first-known ARF decreased, but numbers were small: there were six cases of first-known ARF during Baseline, then five, 1, 0 over the next three years respectively. There was a relationship between household occupancy and numbers (p = 0.018), but not rates (p = 0.447) of infections. This first Australian ARF primordial prevention study provides a feasible model with encouraging findings.

Using Genomics to Understand the Epidemiology of Infectious Diseases in the Northern Territory of Australia

The Northern Territory (NT) is a geographically remote region of northern and central Australia. Approximately a third of the population are First Nations Australians, many of whom live in remote regions. Due to the physical environment and climate, and scale of social inequity, the rates of many infectious diseases are the highest nationally. Molecular typing and genomic sequencing in research and public health have provided considerable new knowledge on the epidemiology of infectious diseases in the NT. We review the applications of genomic sequencing technology for molecular typing, identification of transmission clusters, phylogenomics, antimicrobial resistance prediction, and pathogen detection. We provide examples where these methodologies have been applied to infectious diseases in the NT and discuss the next steps in public health implementation of this technology.

Therapeutics for rheumatic fever and rheumatic heart disease

The goals of acute rheumatic fever therapy are to relieve symptoms, mitigate cardiac valve damage and eradicate streptococcal infection. Preventing future recurrences requires long-term secondary antibiotic prophylaxis and ongoing prevention of Streptococcus pyogenes (group A streptococcus) infections The recommended regimen for secondary prophylaxis comprises benzathine benzylpenicillin G intramuscular injections every four weeks. For patients with non-severe or immediate penicillin hypersensitivity, use erythromycin orally twice daily The goals of therapy for rheumatic heart disease are to prevent progression and optimise cardiac function. Secondary antibiotic prophylaxis can reduce the long-term severity of rheumatic heart disease Patients with rheumatic heart disease, including those receiving benzathine benzylpenicillin G prophylaxis, should receive amoxicillin prophylaxis before undergoing high-risk dental or surgical procedures. If they have recently been treated with a course of penicillin or amoxicillin, or have immediate penicillin hypersensitivity, clindamycin is recommended.

Population pharmacokinetic study of benzathine penicillin G administration in Indigenous children and young adults with rheumatic heart disease in the Northern Territory, Australia

BACKGROUND

Benzathine penicillin G (BPG) is the cornerstone of secondary prophylaxis to prevent Streptococcus pyogenes infections, which precede acute rheumatic fever (ARF). The paucity of pharmacokinetic (PK) data from children and adolescents from populations at the highest risk of ARF and rheumatic heart disease (RHD) poses a challenge for determining the optimal dosing and frequency of injections and undermines efforts to develop improved regimens.

METHODS

We conducted a 6 month longitudinal PK study of young people receiving BPG for secondary prophylaxis. Throat and skin swabs were collected for microbiological culture along with dried blood spot (DBS) samples for penicillin concentrations. DBSs were assayed using LC-MS/MS. Penicillin concentration datasets were analysed using non-linear mixed-effects modelling and simulations performed using published BMI-for-age and weight-for-age data.

RESULTS

Nineteen participants provided 75 throat swabs, 3 skin swabs and 216 penicillin samples. Throat cultures grew group C and G Streptococcus. Despite no participant maintaining penicillin concentration >20 ng/mL between doses, there were no S. pyogenes throat infections and no ARF. The median (range) observed durations >20 ng/mL for the low- and high-BMI groups were 14.5 (11.0-24.25) and 15.0 (7.5-18.25) days, respectively.

CONCLUSIONS

Few patients at highest risk of ARF/RHD receiving BPG for secondary prophylaxis maintain penicillin concentrations above the target of 20 ng/mL beyond 2 weeks during each monthly dosing interval. These PK data suggest that some high-risk individuals may get inadequate protection from every 4 week dosing. Future research should explore this gap in knowledge and PK differences between different populations to inform future dosing schedules.

Valvular Heart Disease Epidemiology

Valvular heart disease is a rapidly growing cause of global cardiovascular morbidity and mortality with diverse and evolving geographic distribution. The prevalence of rheumatic heart disease, the most common valvular heart disease (affecting approximately 41 million people), has been rising in developing nations, likely due to the expansion of the young adult population and the decrease in premature mortality that has resulted from improved access to antibiotics, microbiological testing, and echocardiography. Rheumatic heart disease has also been rising among the impoverished and, often, indigenous populations of developed nations, spurring public health initiatives that are aimed at alleviating healthcare disparities. Aortic valve stenotic disease is the most commonly occurring valvular pathology in developed nations (afflicting 9 million people worldwide) and its prevalence has been increasing with population aging and the increased prevalence of atherosclerosis. Aortic regurgitation is associated with diastolic, but not systolic, hypertension and it has likewise seen a rise in the developed world. Mitral regurgitation affects 24 million people worldwide, with great variability between and among nations. Primary mitral regurgitation arises as a consequence of myxomatous degeneration and mitral valve prolapse, which is largely due to genetic predispositions, while secondary mitral regurgitation accounts for 65% of cases and arises secondary to dilation and heart failure. Tricuspid regurgitation has become more prevalent in developed nations due to the increased usage of intracardiac pacemakers. Infective endocarditis prevalence has also grown in developed nations, likely due to population aging and the increased utilization of transcatheter valve replacement and prosthetic valves as interventions against the previously discussed valvular pathologies.

Living with Rheumatic Heart Disease at the Intersection of Biomedical and Aboriginal Worldviews

Rheumatic heart disease (RHD) significantly impacts the lives of First Nations Australians. Failure to eliminate RHD is in part attributed to healthcare strategies that fail to understand the lived experience of RHD. To rectify this, a PhD study was undertaken in the Northern Territory (NT) of Australia, combining Aboriginal ways of knowing, being and doing with interviews (24 participants from clinical and community settings) and participant observation to privilege Aboriginal voices, including the interpretations and experiences of Aboriginal co-researchers (described in the adjunct article). During analysis, Aboriginal co-researchers identified three interwoven themes: maintaining good feelings; creating clear understanding (from good information); and choosing a good djalkiri (path). These affirm a worldview that prioritises relationships, positive emotions and the wellbeing of family/community. The findings demonstrate the inter-connectedness of knowledge, choice and behaviour that become increasingly complex in stressful and traumatic health, socioeconomic, political, historical and cultural contexts. Not previously heard in the RHD domain, the findings reveal fundamental differences between Aboriginal and biomedical worldviews contributing to the failure of current approaches to communicating health messages. Mitigating this, Aboriginal co-researchers provided targeted recommendations for culturally responsive health encounters, including: communicating to create positive emotions; building trust; and providing family and community data and health messages (rather than individualistic).

Missing Piece Study protocol: prospective surveillance to determine the epidemiology of group A streptococcal pharyngitis and impetigo in remote Western Australia

INTRODUCTION

Group A β-haemolytic Streptococcus (GAS), a Gram-positive bacterium, causes skin, mucosal and systemic infections. Repeated GAS infections can lead to autoimmune diseases acute rheumatic fever (ARF) and rheumatic heart disease (RHD). Aboriginal and Torres Strait Islander peoples in Australia have the highest rates of ARF and RHD in the world. Despite this, the contemporaneous prevalence and incidence of GAS pharyngitis and impetigo in remote Australia remains unknown. To address this, we have designed a prospective surveillance study of GAS pharyngitis and impetigo to collect coincident contemporary evidence to inform and enhance primary prevention strategies for ARF.

METHODS AND ANALYSIS

The Missing Piece Study aims to document the epidemiology of GAS pharyngitis and impetigo through collection of clinical, serological, microbiological and bacterial genomic data among remote-living Australian children. The study comprises two components: (1) screening of all children at school for GAS pharyngitis and impetigo up to three times a year and (2) weekly active surveillance visits to detect new cases of pharyngitis and impetigo. Environmental swabbing in remote schools will be included, to inform environmental health interventions. In addition, the application of new diagnostic technologies, microbiome analysis and bacterial genomic evaluations will enhance primary prevention strategies, having direct bearing on clinical care, vaccine development and surveillance for vaccine clinical trials.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Western Australian Aboriginal Health Ethics Committee (Ref: 892) and Human Research Ethics Committee of the University of Western Australia (Ref: RA/4/20/5101). Study findings will be shared with community members, teachers and children at participating schools, together with academic and medical services. Sharing findings in an appropriate manner is important and will be done in a suitable way which includes plain language summaries and presentations. Finally, findings and updates will also be disseminated to collaborators, researchers and health planners through peer-reviewed journal publications.

"Weaving a Mat That We Can All Sit On": Qualitative Research Approaches for Productive Dialogue in the Intercultural Space

Research remains a site of struggle for First Nations peoples globally. Biomedical research often reinforces existing power structures, perpetuating ongoing colonisation by dominating research priorities, resource allocation, policies, and services. Addressing systemic health inequities requires decolonising methodologies to facilitate new understandings and approaches. These methodologies promote a creative tension and productive intercultural dialogue between First Nations and Western epistemologies. Concurrently, the potential of critical theory, social science, and community participatory action research approaches to effectively prioritise First Nations peoples' lived experience within the biomedical worldview is increasingly recognised. This article describes learnings regarding research methods that enable a better understanding of the lived experience of rheumatic heart disease-an intractable, potent marker of health inequity for First Nations Australians, requiring long-term engagement in the troubled intersection between Indigenist and biomedical worldviews. Working with Yolŋu (Aboriginal) co-researchers from remote Northern Territory (Australia), the concept of ganma (turbulent co-mingling of salt and fresh water) was foundational for understanding and applying relationality (gurrutu), deep listening (nhina, nhäma ga ŋäma), and the use of metaphors-approaches that strengthen productive dialogue, described by Yolŋu co-researchers as weaving a 'mat we can all sit on'. The research results are reported in a subsequent article.