An economic case for a vaccine to prevent group A streptococcus skin infections

Locally acquired strongyloidiasis in remote Australia: why are there still cases?

In Australia, strongyloidiasis primarily affects returned travellers, Vietnam veterans and refugees or asylum seekers, and First Nations people. Non-overseas acquired cases are seen almost exclusively in Australian First Nations remote communities. Australian First Nations communities have one of the highest rates of strongyloidiasis in the world. Our work has shown that strongyloidiasis is a disease of poverty. Acknowledging this is important-we need to shift the lens to socioeconomic factors, particularly environmental health hardware such as working toilets and sewerage systems, showers and laundries, and effective wastewater and rubbish removal. The rates of strongyloidiasis in First Nations communities is a result of decades of inadequate, poorly constructed and/or poorly maintained housing, and poor environmental health hardware (hereafter hardware). The solution lies in adequate funding, resulting in well designed and maintained housing and appropriate hardware. Governments need to allow First Nations communities themselves to take the lead role in funding allocation, and design, construction and maintenance of their housing and hardware. This will ensure housing and hardware fulfils cultural and physical needs and desires, and protects health. Improving housing and hardware will also improve other health outcomes. This article is part of the Theo Murphy meeting issue 'Strongyloides: omics to worm-free populations'.

Insights gained from sequencing Australian non-invasive and invasive Streptococcus pyogenes isolates

Epidemiological data have indicated that invasive infections caused by the Gram-positive cocci Streptococcus pyogenes (group A streptococcus, GAS) have increased in many Australian states over the past two decades. In July 2022, invasive GAS (iGAS) infections became nationally notifiable in Australia via public-health agencies. Surveillance for S. pyogenes infections has been sporadic within the state of New South Wales (NSW). This has led to a lack of genetic data on GAS strains in circulation, particularly for non-invasive infections, which are the leading cause of GAS's burden on the Australian healthcare system. To address this gap, we used whole-genome sequencing to analyse the genomes of 318 S. pyogenes isolates collected within two geographical regions of NSW. Invasive isolates were collected in 2007-2017, whilst non-invasive isolates were collected in 2019-2021. We found that at least 66 different emm-types were associated with clinical disease within NSW. There was no evidence of any Australian-specific clones in circulation. The M1UK variant of the emm1 global pandemic clone (M1global) has been detected in our isolates from 2013 onwards. We detected antimicrobial-resistance genes (mainly tetM, ermA or ermB genes) in less than 10 % of our 318 isolates, which were more commonly associated with non-invasive infections. Superantigen virulence gene carriage was reasonably proportionate between non-invasive and invasive infection isolates. Our study adds rich data on the genetic makeup of historical S. pyogenes infections within Australia. Ongoing surveillance of invasive and non-invasive GAS infections within NSW by whole-genome sequencing is warranted to inform on outbreaks, antimicrobial resistance and vaccine coverage.

A Longitudinal Study of Group A Streptococcal Colonization and Pharyngitis in US Children

BACKGROUND

Group A streptococci (GAS) are a major cause of pharyngitis in children. Recently, there were severe GAS outbreaks. The aims of this study were to assess pharyngeal colonization prevalence in healthy children, to assess different diagnostic definitions for GAS pharyngitis and to estimate incidence rates for these infections.

METHODS

A 2-year longitudinal study was conducted in healthy children in the United States. Pharyngeal swabs were cultured every 3 months for GAS colonization. Serum antistreptolysin O, antideoxyribonuclease B (DNaseB) and antistreptococcal C5a peptidase (SCP) antibody titers were assessed at baseline. When participants developed a sore throat, pharyngeal swabs were collected for rapid antigen detection test (RADT) and culture, and antibody titers were determined in serum samples. A range of case definitions were used for GAS pharyngitis.

RESULTS

A total of 422 children 3-12 years old were enrolled (140, 141 and 141 were 3-5, 6-9 and 10-12 years of age, respectively). The overall prevalence of GAS colonization during the study was 48%. Baseline antistreptolysin O, anti-DNaseB and anti-SCP antibody titers were higher for children older than 5 years. The incidence of GAS pharyngitis per 100 person-years was 15.9 for RADT/culture-proven and 4.6 for serologically confirmed pharyngitis.

CONCLUSIONS

GAS throat colonization and pharyngitis were frequent in children 3-12 years old. The case definition employed impacted the measured incidence of GAS pharyngitis, with higher rates detected using RADT/culture-based definitions. These data suggest that case definition is important and that young children are exposed to GAS, which may inform plans for vaccine development and implementation.

The epidemiology of superficial Streptococcal A (impetigo and pharyngitis) infections in Australia: A systematic review

BACKGROUND

Streptoccocal A (Strep A, GAS) infections in Australia are responsible for significant morbidity and mortality through both invasive (iGAS) and post-streptococcal (postGAS) diseases as well as preceding superficial (sGAS) skin and throat infection. The burden of iGAS and postGAS are addressed in some jurisdictions by mandatory notification systems; in contrast, the burden of preceding sGAS has no reporting structure, and is less well defined. This review provides valuable, contemporaneous evidence on the epidemiology of sGAS presentations in Australia, informing preventative health projects such as a Streptococcal A vaccine and standardisation of primary care notification.

METHODS AND FINDINGS

MEDLINE, Scopus, EMBASE, Web of Science, Global Health, Cochrane, CINAHL databases and the grey literature were searched for studies from an Australian setting relating to the epidemiology of sGAS infections between 1970 and 2020 inclusive. Extracted data were pooled for relevant population and subgroup analysis. From 5157 titles in the databases combined with 186 grey literature reports and following removal of duplicates, 4889 articles underwent preliminary title screening. The abstract of 519 articles were reviewed with 162 articles identified for full text review, and 38 articles identified for inclusion. The majority of data was collected for impetigo in Aboriginal and Torres Strait Islander populations, remote communities, and in the Northern Territory, Australia. A paucity of data was noted for Aboriginal and Torres Strait Islander people living in urban centres or with pharyngitis. Prevalence estimates have not significantly changed over time. Community estimates of impetigo point prevalence ranged from 5.5-66.1%, with a pooled prevalence of 27.9% [95% CI: 20.0-36.5%]. All studies excepting one included >80% Aboriginal and Torres Strait Islander people and all excepting two were in remote or very remote settings. Observed prevalence of impetigo as diagnosed in healthcare encounters was lower, with a pooled estimate of 10.6% [95% CI: 3.1-21.8%], and a range of 0.1-50.0%. Community prevalence estimates for pharyngitis ranged from 0.2-39.4%, with a pooled estimate of 12.5% [95% CI: 3.5-25.9%], higher than the prevalence of pharyngitis in healthcare encounters; ranging from 1.0-5.0%, and a pooled estimate of 2.0% [95% CI: 1.3-2.8%]. The review was limited by heterogeneity in study design and lack of comparator studies for some populations.

CONCLUSIONS

Superficial Streptococcal A infections contribute to an inequitable burden of disease in Australia and persists despite public health interventions. The burden in community studies is generally higher than in health-services settings, suggesting under-recognition, possible normalisation and missed opportunities for treatment to prevent postGAS. The available, reported epidemiology is heterogeneous. Standardised nation-wide notification for sGAS disease surveillance must be considered in combination with the development of a Communicable Diseases Network of Australia (CDNA) Series of National Guideline (SoNG), to accurately define and address disease burden across populations in Australia.

TRIAL REGISTRATION

This review is registered with PROSPERO. Registration number: CRD42019140440.

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.

Modeling the potential health impact of prospective Strep A vaccines

The World Health Organization published the preferred product characteristics for a Group A Streptococcus (Strep A) vaccine in 2018. Based on these parameters for the age of vaccination, vaccine efficacy, duration of protection from vaccine-derived immunity, and vaccination coverage, we developed a static cohort model to estimate the projected health impact of Strep A vaccination at the global, regional, and national levels and by country-income category. We used the model to analyse six strategic scenarios. Based on Strep A vaccine introduction between 2022 and 2034 for the primary scenario, we estimated vaccination at birth for 30 vaccinated cohorts could avert 2.5 billion episodes of pharyngitis, 354 million episodes of impetigo, 1.4 million episodes of invasive disease, 24 million episodes of cellulitis, and 6 million cases of rheumatic heart disease globally. Vaccination impact in terms of burden averted per fully vaccinated individual is highest in North America for cellulitis and in Sub-Saharan Africa for rheumatic heart disease.

Global economic burden per episode for multiple diseases caused by group A Streptococcus

Considering the lack of existing evidence on economic burden for diseases caused by group A Streptococcus, we estimated the economic burden per episode for selected diseases. Each cost component of direct medical costs (DMCs), direct non-medical costs (DNMCs), and indirect costs (ICs) was separately extrapolated and aggregated to estimate the economic burden per episode by income group as classified by the World Bank. Adjustment factors for DMC and DNMC were generated to overcome related data insufficiencies. To address uncertainty surrounding input parameters, a probabilistic multivariate sensitivity was carried out. The average economic burden per episode ranged from $22 to $392 for pharyngitis, $25 to $2,903 for impetigo, $47 to $2,725 for cellulitis, $662 to $34,330 for invasive and toxin-mediated infections, $231 to $6,332 for acute rheumatic fever (ARF), $449 to $11,717 for rheumatic heart disease (RHD), and $949 to $39,560 for severe RHD across income groups. The economic burden for multiple Group A Streptococcus diseases underscores an urgent need to develop effective prevention strategies including vaccines.

Optimal global spending for group A Streptococcus vaccine research and development

Group A Streptococcus (Strep A) leads to 600,000 deaths and 600 million cases of pharyngitis annually. Although long a promising target for vaccine development, how much funding should be allocated to develop a Strep A vaccine is unclear. We aim to calculate the optimal amount of global spending for Strep A vaccine development, the resulting benefits, and the social rate of return on this spending. We develop a model of optimal spending, from a global societal perspective, on research and development (R&D) for vaccines and treatments. The model takes as inputs total harm from the disease, the probability an R&D project succeeds, the cost of a project, and the fraction of total harm a success alleviates. Based on these inputs the model outputs an optimal amount of spending and a rate of return. We calibrate the model for Strep A. Optimal spending is estimated to be 2020 USD33 billion. This spending leads to 2020 USD1.63 trillion in benefits and a real return of 22.3% per year for thirty years. Sensitivity shows an optimal spending range of 15.9 billion to 58.5 billion, a benefits range of 1.6 trillion to 37.9 trillion, and a return range of 18.0-48.2%. Investment in a Strep A vaccine could create enormous benefits for comparatively little cost. It represents one of the highest return uses of public spending. Policy can promote Strep A vaccine development through direct funding of projects and by promoting financial mechanisms that allow the private sector to diversify its R&D investment.

Modalities of group A streptococcal prevention and treatment and their economic justification

Infection by group A Streptococcus (Strep A) results in a diverse range of clinical conditions, including pharyngitis, impetigo, cellulitis, necrotising fasciitis, and rheumatic heart disease. In this article, we outline the recommended strategies for Strep A treatment and prevention and review the literature for economic evaluations of competing treatment and prevention strategies. We find that most economic evaluations focus on reducing the duration of illness or risk of rheumatic fever among people presenting with sore throat through diagnostic and/or treatment strategies. Few studies have evaluated strategies to reduce the burden of Strep A infection among the general population, nor have they considered the local capacity to finance and implement strategies. Evaluation of validated costs and consequences for a more diverse range of Strep A interventions are needed to ensure policies maximise patient outcomes under budget constraints. This should include attention to basic public health strategies and emerging strategies such as vaccination.

Harmonizing Surveillance Methodologies for Group A Streptococcal Diseases

Group A Streptococcus (Strep A) is responsible for a significant global health and economic burden. The recent prioritization of Strep A vaccine development by the World Health Organization has prompted global research activities and collaborations. To progress this prioritization, establishment of robust surveillance for Strep A to generate updated regional disease burden estimates and to establish platforms for future impact evaluation is essential. Through the activities of the Strep A Vaccine Global Consortium (SAVAC), we have refined and harmonized surveillance protocols for 7 Strep A disease endpoints with a view that these will form part of surveillance standards for ongoing research and public health activities.

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.

A systematic framework for prioritising burden of disease data required for vaccine development and implementation: the case for group A streptococcal diseases

Vaccine development and implementation decisions need to be guided by accurate and robust burden of disease data. We developed an innovative systematic framework outlining the properties of such data that are needed to advance vaccine development and evaluation, and prioritize research and surveillance activities. We focus on 4 objectives—advocacy, regulatory oversight and licensure, policy and post-licensure evaluation, and post-licensure financing—and identify key stakeholders and specific requirements for burden of disease data aligned with each objective. We apply this framework to group A Streptococcus, a pathogen with an underrecognized global burden, and give specific examples pertinent to 8 clinical endpoints. This dynamic framework can be adapted for any disease with a vaccine in development and can be updated as vaccine candidates progress through clinical trials. This framework will also help with research and innovation priority setting of the Immunization Agenda 2030 (IA2030) and accelerate development of future vaccines.

Developing an Effective Glycan-based Vaccine for Streptococcus Pyogenes

Streptococcus pyogenes is a primary infective agent that causes approximately 700 million human infections each year, resulting in more than 500,000 deaths. Carbohydrate-based vaccines are proven to be one of the most promising subunit vaccine candidates, as the bacterial glycan pattern(s) are different from mammalian cells and show increased pathogen serotype conservancy than the protein components. In this review we highlight reverse vaccinology for use in the development of subunit vaccines against S. pyogenes, and report reproducible methods of carbohydrate antigen production, in addition to the structure-immunogenicity correlation between group A carbohydrate epitopes and alternative vaccine antigen carrier systems. We also report recent advances used to overcome hurdles in carbohydrate-based vaccine development.

Existing cost-effectiveness analyses for diseases caused by Group A Streptococcus: A systematic review to guide future research

Background: Group A Streptococcus (Strep A) causes a broad spectrum of disease manifestations, ranging from benign symptoms including throat or skin infections, to fatal illness such as rheumatic heart disease, or chronic renal failure. Currently, there is no vaccine available against Strep A infections. Despite the high burden of Strep A-associated infections worldwide, little attention has been paid to the research of these diseases, including standardized surveillance programs, resulting in a lack of economic evaluations for prevention efforts. This study aims at identifying existing cost-effectiveness analyses (CEA) on any Strep A infections. Methods: A systematic literature review was conducted by searching the PubMed electronic database. Results: Of a total of 321, 44 articles met the criteria for inclusion. Overall, CEA studies on Strep A remain limited in number. In particular, a number of available CEA studies on Strep A are disproportionately lower in low-income countries than in high-income countries. Decision-analytic models were the most popular choice for CEA on Strep A. A majority of the models considered pharyngitis and acute rheumatic fever, but it was rare to observe a model which covered a wide range of disease manifestations. Conclusions: Future research is needed to address missing clinical outcomes, imbalance on study locations by income group, and the transmission dynamic of selected diseases.

Protocol for the systematic review of the epidemiology of superficial Streptococcal A infections (skin and throat) in Australia

OBJECTIVE

We have produced a protocol for the comprehensive systematic review of the current literature around superficial group A Streptococcal infections in Australia.

METHODS

MEDLINE, Scopus, EMBASE, Web of Science, Global Health, Cochrane, CINAHL databases and the gray literature will be methodically and thoroughly searched for studies relating to the epidemiology of superficial group A Streptococcal infections between the years 1970 and 2019. Data will be extracted to present in the follow up systematic review.

CONCLUSION

A rigorous and well-organised search of the current literature will be performed to determine the current and evolving epidemiology of superficial group A Streptococcal infections in Australia.

The Australian burden of invasive group A streptococcal disease: a narrative review

The Australian and New Zealand governments have allocated significant funding to advance efforts towards a group A Streptococcus (Strep A) vaccine. The argument for Strep A vaccine development has to date focussed on prevention of non-invasive disease (e.g. pharyngitis) and immune-mediated complications (especially rheumatic heart disease). Because of the poorer prognosis and theoretically more precisely known burden of invasive, compared to non-invasive disease, exploration of the burden of invasive Strep A disease could lend further support to the vaccine business case. This narrative review critically assesses the Australian incidence of invasive Strep A disease. Case notification data were first assessed through government sources, expressing annual incidence as cases per 100 000 population. Published literature accessed through PubMed and MEDLINE was assessed to March 2020. Where estimates could be updated by replicating reported methods with publicly available data, this was performed. Invasive Strep A disease is currently notifiable in Queensland and the Northern Territory only. The magnitude, degree of certainty and recency of estimates vary by state/territory and between sub-populations, including higher incidence among Indigenous Australians compared to non-Indigenous Australians. According to inpatient records from 2017 to 2018, the Australian incidence of invasive Strep A disease was 8.3 per 100 000. However, this is likely to be an underestimate. Preventing invasive Strep A disease is an important use for a Strep A vaccine. This narrative review highlights deficiencies in our current understanding of the Australian disease burden. These difficulties would be overcome by nationally consistent mandatory case reporting.

Household Economic Consequences of Rheumatic Heart Disease in Uganda

Background: Rheumatic heart disease (RHD) has declined dramatically in wealthier countries in the past three decades, but it remains endemic in many lower-resourced regions and can have significant costs to households. The objective of this study was to quantify the economic burden of RHD among Ugandans affected by RHD. Methods: This was a cross-sectional cost-of-illness study that randomly sampled 87 participants and their households from the Uganda National RHD registry between December 2018 and February 2020. Using a standardized survey instrument, we asked participants and household members about outpatient and inpatient RHD costs and financial coping mechanisms incurred over the past 12 months. We used descriptive statistics to analyze levels and distributions of costs and the frequency of coping strategies. Multivariate Poisson regression models were used to assess relationships between socioeconomic characteristics and utilization of financial coping mechanisms. Results: Most participants were young or women, demonstrating a wide variation in socioeconomic status. Outpatient and inpatient costs were primarily driven by transportation, medications, and laboratory tests, with overall RHD direct and indirect costs of $78 per person-year. Between 20 and 35 percent of households experienced catastrophic healthcare expenditure, with participants in the Northern and Western Regions 5-10 times more likely to experience such hardship and utilize financial coping mechanisms than counterparts in the Central Region, a wealthier area. Increases in total RHD costs were positively correlated with increasing use of coping behaviors. Conclusion: Ugandan households affected by RHD, particularly in lower-income areas, incur out-of-pocket costs that are very high relative to income, exacerbating the poverty trap. Universal health coverage policy reforms in Uganda should include mechanisms to reduce or eliminate out-of-pocket expenditures for RHD and other chronic diseases.

Potential Therapeutic Approaches through Modulating the Autophagy Process for Skin Barrier Dysfunction

Autophagy is an attractive process to researchers who are seeking novel potential treatments for various diseases. Autophagy plays a critical role in degrading damaged cellular organelles, supporting normal cell development, and maintaining cellular homeostasis. Because of the various effects of autophagy, recent human genome research has focused on evaluating the relationship between autophagy and a wide variety of diseases, such as autoimmune diseases, cancers, and inflammatory diseases. The skin is the largest organ in the body and provides the first line of defense against environmental hazards, including UV damage, chemical toxins, injuries, oxidative stress, and microorganisms. Autophagy takes part in endogenous defense mechanisms by controlling skin homeostasis. In this manner, regulating autophagy might contribute to the treatment of skin barrier dysfunctions. Various studies are ongoing to elucidate the association between autophagy and skin-related diseases in order to find potential therapeutic approaches. However, little evidence has been gathered about the relationship between autophagy and the skin. In this review, we highlight the previous findings of autophagy and skin barrier disorders and suggest potential therapeutic strategies. The recent research regarding autophagy in acne and skin aging is also discussed.

Invasive Group B Streptococcus Infections in Adults, England, 2015-2016

During 2015–2016, a total of 3,156 episodes of invasive group B Streptococcus (iGBS) infection in adults (>15 years of age) were recorded in England, corresponding to an annual incidence of 3.48/100,000 population. iGBS incidence was highest in older patients and women of childbearing age. The 493 pregnancy-related iGBS episodes correspond to a rate of 1.34/10,000 live births. In adults up to 60–69 years of age and in pregnant women, iGBS incidence increased with higher levels of socioeconomic deprivation. Hospital admissions associated with iGBS were predominantly emergency admissions (73% [2,260/3,099]); only 7% of nonpregnancy iGBS diagnoses were made >48 hours after admission. Underlying conditions were highly prevalent in nonpregnant adult case-patients, including cardiovascular (57%), lung (43%), and kidney (45%) disease and diabetes (40%). Post-iGBS episode 30-day and 12-month all-cause mortality rates in nonpregnant adults were 12% and 24%, respectively. No pregnancy-related iGBS deaths were identified.

Increasing incidence of invasive group A streptococcal disease in Western Australia, particularly among Indigenous people

OBJECTIVE

To quantify the burden of invasive group A Streptococcus (GAS) disease in Western Australia during 2000-2018.

DESIGN, SETTING

Population-based data linkage study: Hospital Morbidity Data Collection (HMDC; all WA public and private hospital records), PathWest pathology data (government-owned pathology services provider), and death registrations.

PARTICIPANTS

People with invasive GAS disease, defined by an isolate from a normally sterile site (PathWest) or a hospital-based principal ICD-10-AM diagnosis code (HMDC).

MAIN OUTCOME MEASURES

Incidence of invasive GAS disease; median length of hospital stay; all-cause mortality.

RESULTS

We identified 2237 cases of GAS disease during 2000-2018; 1283 were in male patients (57%). 1950 cases had been confirmed by GAS isolates from normally sterile tissues (87%; including 1089 from blood [56% of cases] and 750 from tissue [38%]). The age-standardised incidence increased from 2.0 (95% CI, 1.4-2.7) cases per 100 000 population in 2000 to 9.1 (95% CI, 7.9-10.2) cases per 100 000 in 2017 (by year, adjusted for age group and sex: incidence rate ratio [IRR], 1.09; 95% CI, 1.08-1.10). Incidence was consistently higher among Indigenous than non-Indigenous Australians (year-adjusted IRR, 13.1; 95% CI, 11.3-15.1). All-cause 30-day mortality was 5% (116 deaths), and 90-day mortality 7% (156 deaths); 30-day mortality, adjusted for age group and sex, was not statistically significantly different for cases involving Indigenous or non-Indigenous patients (adjusted odds ratio, 0.8; 95% CI, 0.6-1.1).

CONCLUSIONS

The incidence of invasive GAS disease in WA increased between 2000 and 2018, particularly among Indigenous Australians. Mandatory notification of invasive GAS disease would therefore be appropriate. The social determinants of differences in incidence should be addressed, and other relevant host, pathogen, and health system factors investigated.

Descriptive analysis of group A Streptococcus in skin swabs and acute rheumatic fever, Auckland, New Zealand, 2010-2016

Background

Group A Streptococcus (GAS) can trigger an immune-mediated response resulting in acute rheumatic fever (ARF). Historically, ARF has been considered a consequence of preceding GAS pharyngitis, but increasing evidence suggests that GAS skin infections may be a driver. Data on the primary care burden of GAS skin infection are limited. This paper aims to describe and compare the prevalence and distribution of GAS detection in skin swabs and ARF rates in the Auckland population.

Methods

This cross-sectional study used all laboratory skin swab data from people who had a skin swab taken as a result of a consultation with a health professional in the Auckland region (2010–2016). Initial primary hospitalisations for ARF were identified and all data were linked using unique patient identifiers to patient's age, prioritised ethnicity, sex, and socio-economic status.

Findings

377,410 skin swabs from 239,494 individuals were included. 12·8% of swabs were GAS positive, an annual incidence of 4·8 per 1,000 person-years. Māori and Pacific Peoples under 20 years of age had markedly higher GAS detection in skin swabs (RR 4·0; 95% CI 3·9–4·2: RR 6·8; 95% CI 6·6–7·0) and significantly higher ARF rates (RR 30·3; 95% CI 19·5–46·9: RR 69·7 95% CI 45·8–106·1) compared with European/Other ethnicities.

Interpretation

The observation that GAS detection was markedly higher in Māori and Pacific Peoples provides a potential explanation for the marked ethnic differences in ARF. These findings support a greater focus on addressing the burden of skin infection in NZ, including as ARF prevention.

Funding

The first author received a training stipend from the New Zealand College of Public Health Medicine (NZCPHM) during her Masters of Public Health.

Cellulitis in children: a retrospective single centre study from Australia

AIM

To characterise the epidemiology, clinical features and treatment of paediatric cellulitis.

METHODS

A retrospective study of children presenting to a paediatric tertiary hospital in Western Australia, Australia in 2018. All inpatient records from 1 January to 31 December 2018 and emergency department presentations from 1 July to 31 December 2018 were screened for inclusion.

RESULTS

302 episodes of cellulitis were included comprising 206 (68.2%) admitted children and 96 (31.8%) non-admitted children. The median age was 5 years (IQR 2-9), 40 (13.2%) were Aboriginal and 180 (59.6%) boys. The extremities were the most commonly affected body site among admitted and non-admitted patients. There was a greater proportion of facial cellulitis in admitted patients (27.2%) compared with non-admitted patients (5.2%, p<0.01). Wound swab was the most frequent microbiological investigation (133/302, 44.0%), yielding positive cultures in the majority of those tested (109/133, 82.0%). The most frequent organisms identified were Staphylococcus aureus (94/109, 86.2%) (methicillin-susceptible S. aureus (60/94, 63.8%), methicillin-resistant S. aureus) and Streptococcus pyogenes (22/109, 20.2%) with 14 identifying both S. aureus and S. pyogenes. Intravenous flucloxacillin was the preferred antibiotic (154/199, 77.4%), with median intravenous duration 2 days (IQR 2-3), oral 6 days (IQR 5-7) and total 8 days (IQR 7-10).

CONCLUSIONS

Cellulitis is a common reason for presentation to a tertiary paediatric hospital. We confirm a high prevalence of extremity cellulitis and demonstrate that children with facial cellulitis often require admission. Cellulitis disproportionately affected Aboriginal children and children below 5 years. Prevention of cellulitis involves early recognition and treatment of skin infections such as impetigo and scabies.

The economic and health burdens of diseases caused by group A Streptococcus in New Zealand

OBJECTIVES

In preparation for the future arrival of a group A Streptococcus (GAS) vaccine, this study estimated the economic and health burdens of GAS diseases in New Zealand (NZ).

METHODS

The annual incidence of GAS diseases was based on extrapolation of the average number of primary healthcare episodes managed each year in general practices (2014-2016) and on the average number of hospitalizations occurring each year (2005-2014). Disease incidence was multiplied by the average cost of diagnosing and managing an episode of disease at each level of care to estimate the annual economic burden.

RESULTS

GAS affected 1.5% of the population each year, resulting in an economic burden of 29.2 million NZ dollars (2015 prices) and inflicting a health burden of 2373 disability-adjusted life years (DALYs). Children <5 years of age were the most likely age group to present for GAS-related healthcare. Presentations for superficial throat and skin infections (predominantly pharyngitis and impetigo) were more common than other GAS diseases. Cellulitis contributed the most to the total economic and health burdens. Invasive and immune-mediated diseases disproportionately contributed to the total economic and health burdens relative to their frequency of occurrence.

CONCLUSION

Preventing GAS diseases would have substantial economic and health benefits in NZ and globally.

Economic consequences of rheumatic heart disease: A scoping review

BACKGROUND

Rheumatic heart disease (RHD) remains endemic in less-resourced regions and countries and results in high medical and non-medical costs to households, health systems, and society. This scoping review maps out the available evidence on the economic impact of RHD and its antecedents and suggests future research priorities.

METHOD

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews. We identified articles through systematic electronic database search supplemented by expert knowledge of unpublished literature. Studies were included if they collected empirical RHD-related costing data as a primary or secondary objective and if the data were collected from 2000 onward. Main quantitative findings by intervention, costing perspective, and location were charted, and a standardized quality assessment tool was used to appraise included studies.

RESULTS

The index search identified 2519 electronic records and two grey-literature graduate theses. Six full texts were included in the review. Primary prevention costs were modest, while secondary and especially tertiary prevention were more costly. Most estimates were of health sector costs and for tertiary interventions. Only two studies described RHD-related costs in non-high-income countries. Most studies were of adequate methodological quality.

CONCLUSION

Research into the costs of RHD has mostly been done in wealthy countries. Costs from the household perspective, which are particularly important in countries with limited public healthcare finance, are lacking. To inform advocacy and guide implementation of the 2018 World Health Assembly resolution on RHD, high-quality, local cost estimates will be needed from a range of representative, RHD-endemic countries.

Priorities for improved management of acute rheumatic fever and rheumatic heart disease: analysis of cross-sectional continuous quality improvement data in Aboriginal primary healthcare centres in Australia

Objective This study investigated the delivery of guideline-recommended services for the management of acute rheumatic fever (ARF) and rheumatic heart disease (RHD) in Australian primary healthcare centres participating in the Audit and Best Practice for Chronic Disease (ABCD) National Research Partnership project. Methods ARF and RHD clinical audit data were collected from 63 Aboriginal centres in four Australian jurisdictions using the ABCD ARF/RHD audit tool. Records of up to 30 patients treated for ARF and/or RHD were analysed per centre from the most recent audit conducted between 2009 and 2014. The main outcome measure was a quality of ARF and RHD care composite indicator consisting of nine best-practice service items. Results Of 1081 patients, most were Indigenous (96%), female (61%), from the Northern Territory and Queensland (97%) and <25 years of age (49%). The composite indicator was highest in the 0-14 year age group (77% vs 65-67% in other age groups). Timely injections and provision of client education are important specific areas for improvement. Multiple regression showed age >15 years to be a significant negative factor for several care indicators, particularly for the delivery of long-acting antibiotic injections and specialist services in the 15-24 year age group. Conclusions The results suggest that timely injection and patient education are priorities for managing ARF and RHD, particularly focusing on child-to-adult transition care. What is known about the topic? The burden of rheumatic fever and RHD in some Aboriginal communities is among the highest documented globally. Guideline-adherent RHD prevention and management in primary health care (PHC) settings are critically important to reduce this burden. Continuous quality improvement (CQI) is a proven strategy to improve guideline adherence, using audit cycles and proactive engagement of PHC end users with their own data. Previously, such CQI strategies using a systems approach were shown to improve delivery of ARF and RHD care in six Aboriginal health services (three government and three community controlled). What does this paper add? This paper focuses on the variation across age groups in the quality of ARF and/or RHD care according to nine quality of care indicators across 63 PHC centres serving the Aboriginal population in the Northern Territory, Queensland, South Australia and Western Australia. These new findings provide insight into difference in quality of care by life stage, indicating particular areas for improvement of the management of ARF and RHD at the PHC level, and can act as a baseline for monitoring of care quality for ARF and RHD into the future. What are the implications for practitioners? Management plans and innovative strategies or systems for improving adherence need to be developed as a matter of urgency. PHC professionals need to closely monitor adherence to secondary prophylaxis at both the clinic and individual level. RHD priority status needs to be assigned and recorded as a tool to guide management. Systems strengthening needs to particularly target child-to-adult transition care. Practitioners are urged to keep a quick link to the RHDAustralia website to access resources and guidelines pertaining to ARF and RHD (https://www.rhdaustralia.org.au/arf-rhd-guideline, accessed 3 October 2019). CQI strategies can assist PHC centres to improve the care they provide to patients.

Skin infections in Australian Aboriginal children: a narrative review

Impetigo, scabies, cellulitis and abscesses are common in Australian Aboriginal children. These conditions adversely affect wellbeing and are associated with serious long term sequelae, including invasive infection and post‐infectious complications, such as acute post‐streptococcal glomerulonephritis and acute rheumatic fever, which occurs at the highest documented rates in the world in remote Aboriginal communities.

Observational research in remote communities in northern Australia has demonstrated a high concurrent burden of scabies and impetigo and their post‐infectious complications.

Few data are available for other Australian states, especially for urban Aboriginal children; however, nationwide hospital data indicate that the disparity between Aboriginal and non‐Aboriginal children in skin infection prevalence also exists in urban settings.

The Australian National Healthy Skin Guideline summarises evidence‐based treatment of impetigo, scabies and fungal infections in high burden settings such as remote Aboriginal communities. It recommends systemic antibiotics for children with impetigo, and either topical permethrin or oral ivermectin (second line) for the individual and their contacts as equally efficacious treatments for scabies. β‐Lactams are the treatment of choice and trimethoprim–sulfamethoxazole and clindamycin are effective alternatives for treatment of paediatric cellulitis. Abscesses require incision and drainage and a 5‐day course of trimethoprim–sulfamethoxazole or clindamycin.

Addressing normalisation of skin infections and the social determinants of skin health are key challenges for the clinician. Research is underway on community‐wide skin health programs and the role for mass drug administration which will guide future management of these common, treatable diseases.

Study of the impact of long-duration space missions at the International Space Station on the astronaut microbiome

Over the course of a mission to the International Space Station (ISS) crew members are exposed to a number of stressors that can potentially alter the composition of their microbiomes and may have a negative impact on astronauts’ health. Here we investigated the impact of long-term space exploration on the microbiome of nine astronauts that spent six to twelve months in the ISS. We present evidence showing that the microbial communities of the gastrointestinal tract, skin, nose and tongue change during the space mission. The composition of the intestinal microbiota became more similar across astronauts in space, mostly due to a drop in the abundance of a few bacterial taxa, some of which were also correlated with changes in the cytokine profile of crewmembers. Alterations in the skin microbiome that might contribute to the high frequency of skin rashes/hypersensitivity episodes experienced by astronauts in space were also observed. The results from this study demonstrate that the composition of the astronauts’ microbiome is altered during space travel. The impact of those changes on crew health warrants further investigation before humans embark on long-duration voyages into outer space.

Controlled human infection for vaccination against Streptococcus pyogenes (CHIVAS): Establishing a group A Streptococcus pharyngitis human infection study

Group A Streptococcus (GAS) is a highly-adapted and human-restricted pathogen responsible for a high global burden of disease across a diverse clinical spectrum. Vaccine development has been impeded by scientific, regulatory, and commercial obstacles. Human infection studies (HIS) are increasingly contributing to drug, diagnostics, and vaccine development, reducing uncertainty at early stages, especially for pathogens with animal models that incompletely reproduce key elements of human disease. We review the small number of historical GAS HIS and present the study protocol for a dose-ranging inpatient study in healthy adults. The primary objective of the study is to establish a new GAS pharyngitis HIS with an attack rate of at least 60% as a safe and reliable platform for vaccine evaluation and pathogenesis research. According to an adaptive dose-ranging study design, emm75 GAS doses manufactured in keeping with principles of Good Manufacturing Practice will be directly applied by swab to the pharynx of carefully screened healthy adult volunteers at low risk of severe complicated GAS disease. Participants will remain as closely monitored inpatients for up to six days, observed for development of the primary outcome of acute symptomatic pharyngitis, as defined by clinical and microbiological criteria. All participants will be treated with antibiotics and followed as outpatients for six months. An intensive sampling schedule will facilitate extensive studies of host and organism dynamics during experimental pharyngitis. Ethics approval has been obtained and the study has been registered at ClinicalTrials.gov (NCT03361163).