Systematic review of household transmission of Strep A: A potential site for prevention that has eluded attention.

BACKGROUND: Despite being the sixth most common infectious disease globally, transmission of Streptococcus pyogenes (Strep A) within the household remains an understudied driver of infection. We undertook a systematic review to better understand the transmission of Strep A between people within the home while highlighting opportunities for prevention. METHODS: A search strategy was applied to five databases between September 2022 and March 2023. Results were limited to those published between January 2000 and March 2023. Texts were reviewed by two authors and the following data extracted: article details (title, author, year), study type, transmission year, country, participant age/s, infection status, molecular testing, and transmission mode. Funding was provided by the Australian National Health and Medical Research Council (NHMRC, grant number GNT2010716). RESULTS: The final analysis comprised 28 texts. Only seven studies (25.0%) provided sufficient detail to identify the Strep A transmission mode. These were contact (4), vehicle (bedding; clothing; other fabric, and medical equipment, [2]), and contact with animals (1). All others were classified as household (specific mode unascertainable). Most articles reported outbreaks involving invasive Strep A infections. CONCLUSIONS: There is limited literature regarding household transmission of Strep A. Understanding transmission in this setting remains imperative to guide control methods.

The health impacts of ambient air pollution in Australia: a systematic literature review.

Ambient (outdoor) air pollution is a key risk factor for health for which effective policy plays an important preventative role. Australian federal and related state air quality standards have historically relied on international evidence for guidance, which may not accurately reflect the Australian context. However, there has been a large increase in Australian epidemiological studies over recent years. The aim of this study is to provide an updated systematic literature review of peer-reviewed epidemiological studies that examined the health impacts of outdoor air pollution in Australia, including short- and long-term exposure. Following PRISMA guidelines, we conducted a systematic literature review. Broad search terms were applied to two databases (PubMed and Web of Science) and Google Scholar. Quality assessment and risk of bias were assessed using standard metrics. Included studies were summarised by tabulating key study characteristics, grouped by health outcomes. In total, 72 studies were included in the review. Sixty-four (89%) studies used daily or hourly pollutant concentrations to examine short-term exposure impacts, of which 59 (92%) revealed significant associations with one or more health outcomes, including cardio-respiratory, all-cause mortality or morbidity and birth outcomes. Eight (11%) studies used annual average pollutant concentrations to investigate the long-term exposure finding significant associations with asthma, reduced lung function, atopy and cardio-respiratory mortality across five studies. The remaining three studies found no significant association with asthma, mortality and a range of self-reported diseases, respectively. Ambient air pollution has substantial health impacts in Australia. The body of domestic evidence has increased markedly since national air quality standards were first set in the 1990s, which could be drawn on by policy-makers when revising the existing standards, or considering new standards.

Transmission potential of Streptococcus pyogenes during a controlled human infection trial of pharyngitis.

Controlled human infection (CHI) models can provide insights into transmission of pathogens such as Streptococcus pyogenes (Strep A). As part of the Controlled Human Infection with Penicillin for Streptococcus pyogenes (CHIPS) trial, we explored the potential for transmission among participants deliberately infected with the Strep A emm75 strain. Three approaches to understanding transmission were employed: the use of agar settle plates to capture possible droplet or airborne spread of Strep A; measurement of distance droplets could spread during conversation; and environmental swabbing of high-touch items to detect Strep A on surfaces. Of the 60 (27%) CHIPS trial participants across five cohorts, 16 were enrolled in this sub-study; availability of study staff was the primary reason for selection. In total, 189 plates and 260 swabs were collected. Strep A was grown on one settle plate from a participant on the second day, using plates placed 30 cm away. This participant received the placebo dose of penicillin and had met the primary endpoint of pharyngitis. Whole-genome sequencing identified this to be the challenge strain. Strep A was not detected on any swabs. In this small sample of CHI participants, we did not find evidence of Strep A transmission by the airborne route or fomites, and just one instance of droplet spread while acutely symptomatic with streptococcal pharyngitis. Although these experiments provide evidence of minimal transmission within controlled clinical settings, greater efforts are required to explore Strep A transmission in naturalistic settings.IMPORTANCEStreptococcus pyogenes remains a significant driver of morbidity and mortality, particularly in under-resourced settings. Understanding the transmission modalities of this pathogen is essential to ensuring the success of prevention methods. This proposed paper presents a nascent attempt to determine the transmission potential of Streptococcus pyogenes nested within a larger controlled human infection model.

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.

Planetary health learning objectives: foundational knowledge for global health education in an era of climate change.

Planetary health is an emerging field that emphasises that humans depend on a healthy Earth for survival and, conversely, that the sustainability of Earth systems is dependent on human behaviours. In response to member demands for resources to support teaching and learning related to planetary health, the Consortium of Universities for Global Health (CUGH) convened a working group to develop a set of planetary health learning objectives (PHLOs) that would complement the existing ten CUGH global health learning objectives. The eight PHLOs feature Earth system changes, planetary boundaries, and climate change science; ecological systems and One Health; human health outcomes; risk assessment, vulnerability, and resilience; policy, governance, and laws (including the UN Framework Convention on Climate Change and the Paris Agreement); roles and responsibilities of governments, businesses, civil society organisations, other institutions, communities, and individuals for mitigation, adaptation, conservation, restoration, and sustainability; environmental ethics, human rights, and climate justice; and environmental literacy and communication. Educators who use the PHLOs as a foundation for teaching, curriculum design, and programme development related to the health-environment nexus will equip learners with a knowledge of planetary health science, interventions, and communication that is essential for future global health professionals.

Searching for Strep A in the clinical environment during a human challenge trial: a sub-study protocol.

Streptococcus pyogenes (also known as group A Streptococcus , Strep A) is an obligate human pathogen with significant global morbidity and mortality. Transmission is believed to occur primarily between individuals via respiratory droplets, but knowledge about other potential sources of transmission via aerosols or the environment is limited. Such knowledge is required to design optimal interventions to control transmission, particularly in endemic settings. We aim to detail an experimental methodology to assess the transmission potential of Strep A in a clinical environment. We will examine potential sources of transmission in up to 20 participants recruited to the Controlled human infection for penicillin against Streptococcus pyogenes (CHIPS) Trial. Three approaches to understanding transmission will be used: the use of selective agar settle plates to capture possible droplet or airborne spread of Strep A; measurement of the possible distance of Strep A droplet spread during conversation; and environmental swabbing of personal and common high-touch items to detect the presence of Strep A on hard and soft surfaces. All methods are designed to allow for an assessment of transmission potential by symptomatic, asymptomatic and non-cases. Ethical approval has been obtained through Bellberry Human Research Ethics Committee (approval 2021-03-295). Trial registration number: ACTRN12621000751875. Any results elicited from these experiments will be of benefit to the scientific literature in improving our knowledge of opportunities to prevent Strep A transmission as a direct component of the primordial prevention of rheumatic fever. Findings will be reported at local, national and international conferences and in peer-reviewed journals.

Community-Led Health Initiatives for Torres Straits Island Communities in a Changing Climate: Implementing Core Values for Mitigation and Adaptation.

First Nations Peoples have a long history of living in Australia's changing climate and a deep knowledge of their traditional estate ('Country'). However, human-induced climate change raises unforeseen risks to the health of First Nations Peoples-especially in remotely located communities. This includes the Torres Strait Islands, where a local leader asked our Torres Strait Islander co-author, 'We know that you will return to your Country-unlike previous researchers. So how can you help with climate change?' In response, this research describes four core values focused on supporting First Nations Peoples' health and wellbeing: co-design, appropriate governance, support for self-determination, and respectfully incorporating Indigenous Knowledges into health-protective climate initiatives. Supporting the health and wellbeing of Torres Strait Islanders to continue living in the remote Torres Strait Islands in a changing climate can enable long-term care for Country, maintenance of culture, and a sense of identity for First Nations Peoples. Ensuring these core values are implemented can support the health of present and future generations and will likely be applicable to other First Nations communities.