Searching for a technology-driven acute rheumatic fever test: the START study protocol

Acute rheumatic fever and rheumatic heart disease: updates in diagnosis and treatment

PURPOSE OF REVIEW

To summarize the latest developments in rheumatic fever and rheumatic heart disease (RHD) prevention, (early) diagnosis, and treatment.

RECENT FINDINGS

The revised Jones criteria have demonstrated increased sensitivity and specificity for rheumatic fever diagnosis in high-risk populations. The management of rheumatic fever remains symptom-based, with no treatment options proven to alter the disease course or prevent chronic RHD. The revised World Heart Federation (WHF) guidelines for the echocardiographic diagnosis of RHD encourage task-shifting of RHD screening, extending reach in endemic regions. These guidelines also present an A-D classification of RHD and provide recommendations for the management of early disease. Integrated models for RHD screening within existing health structures are emerging and automated intelligence is showing potential to support RHD screening and diagnosis. Innovative strategies to foster adherence and equitable access to secondary prophylaxis, such as re-examination of the efficacy of oral penicillin, trials of longer acting penicillin formulations and implants are underway. There is renewed interest and investment in a well tolerated and effective GAS vaccine.

SUMMARY

We are living in a time of possibility with global acceleration to address the prevailing burden of RHD. Together, we can ensure that RHD does not once again fall off the global health agenda, until equitable elimination has been achieved.

An acute rheumatic fever immune signature comprising inflammatory markers, IgG3, and Streptococcus pyogenes-specific antibodies

Understanding the immune profile of acute rheumatic fever (ARF), a serious post-infectious sequelae of Streptococcal pyogenes (group A Streptococcus [GAS]), could inform disease pathogenesis and management. Circulating cytokines, immunoglobulins, and complement were analyzed in participants with first-episode ARF, swab-positive GAS pharyngitis and matched healthy controls. A striking elevation of total IgG3 was observed in ARF (90% > clinical reference range for normal). ARF was also associated with an inflammatory triad with significant correlations between interleukin-6, C-reactive protein, and complement C4 absent in controls. Quantification of GAS-specific antibody responses revealed that subclass polarization was remarkably consistent across the disease spectrum; conserved protein antigens polarized to IgG1, while M-protein responses polarized to IgG3 in all groups. However, the magnitude of responses was significantly higher in ARF. Taken together, these findings emphasize the association of exaggerated GAS antibody responses, IgG3, and inflammatory cytokines in ARF and suggest IgG3 testing could beneficially augment clinical diagnosis.

Are we missing opportunities to detect acute rheumatic fever and rheumatic heart disease in hospital care? A multijurisdictional cohort study

Objective This study aimed to investigate potential missed diagnoses of acute rheumatic fever and rheumatic heart disease during hospital-based care among persons subsequently identified with these conditions. Methods This retrospective cohort study used linked emergency department and inpatient administrative records from Queensland, Northern Territory, South Australia, and New South Wales during 2003-2018 (varying between jurisdictions by completeness of data) of all persons first identified with acute rheumatic fever or rheumatic heart disease while aged 8-24years. Using coded discharge diagnoses from the preceding 3years, we identified presentations (e.g. joint pains or heart murmur without specific identified cause) that potentially mimic and thereby represent a missed opportunity to detect acute rheumatic fever or rheumatic heart disease. Sociodemographic factors associated with experiencing ≥1 mimic diagnoses were investigated using multivariable logistic regression models. Results Among 1855 persons, 65 (3.5%) (using narrow diagnostic inclusions) and 146 (7.9%) (with broad inclusions) experienced ≥1 mimic diagnosis. Joint disorders predominated. Mimics categorised as 'high-likelihood' (most specific) were more frequent among persons subsequently diagnosed as young adults (18-24years) than as children (8-12years) (odds ratio [OR] 2.45, 95% confidence interval [CI] 1.34-4.47), and those from low-risk ethnic groups (including Australian-born non-Indigenous persons) compared with Aboriginal and Torres Strait Islander peoples (OR 2.44, 95% CI 1.02-5.85). Conclusion Missed opportunities to detect acute rheumatic fever and rheumatic heart disease continue to occur in Australian hospitals, and present disproportionately among persons from demographic groups considered to be at low risk, suggesting the need for enhanced clinical suspicion in these groups.

Application of Transthoracic Echocardiography for Cardiac Safety Evaluation in the Clinical Development Process of Vaccines Against Streptococcus pyogenes

Superficial infections with Streptococcus pyogenes (Strep A), pharyngitis and impetigo can induce acute rheumatic fever, an autoimmune sequela manifesting mostly with arthritis and rheumatic carditis. Valvular heart damage can persist or advance following repeated episodes of acute rheumatic fever, causing rheumatic heart disease. Acute rheumatic fever and rheumatic heart disease disproportionately affect children and young adults in developing countries and disadvantaged communities in developed countries. People living with rheumatic heart disease are at risk of experiencing potentially fatal complications such as heart failure, bacterial endocarditis or stroke. Transthoracic echocardiography plays a central role in diagnosing both rheumatic carditis and rheumatic heart disease. Despite the obvious medical need, no licensed Strep A vaccines are currently available, as their clinical development process faces several challenges, including concerns for cardiac safety. However, the development of Strep A vaccines has been recently relaunched by many vaccine developers. In this context, a reliable and consistent safety evaluation of Strep A vaccine candidates, including the use of transthoracic echocardiography for detecting cardiac adverse events, could greatly contribute to developing a safe and efficacious product in the near future. Here, we propose a framework for the consistent use of transthoracic echocardiography to proactively detect cardiac safety events in clinical trials of Strep A vaccine candidates.

The roles of immuno-modulator treatment and echocardiographic screening in rheumatic fever and rheumatic heart disease control: research from Aotearoa, New Zealand

This review summarises advances in research from Aotearoa, New Zealand (NZ) that have potential to reduce the inequitable distribution of acute rheumatic fever (ARF) and rheumatic heart disease (RHD). ARF incidence and RHD prevalence are unacceptably inequitable for Māori and Pacifica. Recent qualitative research has demonstrated mismatches between the lived experience of those with ARF/RHD and health service experience they encounter. NZ-led research has contributed knowledge to all stages of disease prevention (primordial, primary and secondary) and for tertiary management. Modifiable risk factors for ARF are racism across health sectors, household crowding, barriers to accessing primary health care, a high intake of sugar-sweetened beverages and preceding sore throat and skin infections. NZ research has evaluated the impact of a large-scale sore throat management programme and Streptococcal A vaccine development. This review highlights two programme domains of research by the authors that have the potential to reduce the burden of chronic RHD: firstly, effective immunomodulation of ARF to reduce the severity of carditis, with current clinical trials of hydroxychloroquine in NZ; secondly, the development of echocardiographic screening of previously undetected RHD. This now meets criteria for an effective screening test and has potential translation for disease control of RHD.

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.

Research priorities for the secondary prevention and management of acute rheumatic fever and rheumatic heart disease: a National Heart, Lung, and Blood Institute workshop report

Secondary prevention of acute rheumatic fever (ARF) and rheumatic heart disease (RHD) involves continuous antimicrobial prophylaxis among affected individuals and is recognised as a cornerstone of public health programmes that address these conditions. However, several important scientific issues around the secondary prevention paradigm remain unresolved. This report details research priorities for secondary prevention that were developed as part of a workshop convened by the US National Heart, Lung, and Blood Institute in November 2021. These span basic, translational, clinical and population science research disciplines and are built on four pillars. First, we need a better understanding of RHD epidemiology to guide programmes, policies, and clinical and public health practice. Second, we need better strategies to find and diagnose people affected by ARF and RHD. Third, we urgently need better tools to manage acute RF and slow the progression of RHD. Fourth, new and existing technologies for these conditions need to be better integrated into healthcare systems. We intend for this document to be a reference point for research organisations and research sponsors interested in contributing to the growing scientific community focused on RHD prevention and control.

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.

Recent Advances in the Rheumatic Fever and Rheumatic Heart Disease Continuum

Nearly a century after rheumatic fever (RF) and rheumatic heart disease (RHD) was eradicated from the developed world, the disease remains endemic in many low- and middle-income countries (LMICs), with grim health and socioeconomic impacts. The neglect of RHD which persisted for a semi-centennial was further driven by competing infectious diseases, particularly the human immunodeficiency virus (HIV) pandemic. However, over the last two-decades, slowly at first but with building momentum, there has been a resurgence of interest in RF/RHD. In this narrative review, we present the advances that have been made in the RF/RHD continuum over the past two decades since the re-awakening of interest, with a more concise focus on the last decade's achievements. Such primary advances include understanding the genetic predisposition to RHD, group A Streptococcus (GAS) vaccine development, and improved diagnostic strategies for GAS pharyngitis. Echocardiographic screening for RHD has been a major advance which has unearthed the prevailing high burden of RHD and the recent demonstration of benefit of secondary antibiotic prophylaxis on halting progression of latent RHD is a major step forward. Multiple befitting advances in tertiary management of RHD have also been realized. Finally, we summarize the research gaps and provide illumination on profitable future directions towards global eradication of RHD.