Early oral antibiotic switch in Staphylococcus aureus bacteraemia: The Staphylococcus aureus Network Adaptive Platform (SNAP) Trial Early Oral Switch Protocol.

BACKGROUND: Staphylococcus aureus bloodstream infection (bacteraemia) is traditionally treated with at least two weeks of IV antibiotics in adults, 3-7 days in children, and often longer for those with complicated disease. The current practice of treating S. aureus bacteraemia (SAB) with prolonged IV antibiotics (rather than oral antibiotics) is based on historical observational research and expert opinion. Prolonged IV antibiotic therapy has significant disadvantages for patients and healthcare systems, and there is growing interest in whether a switch to oral antibiotics following an initial period of IV therapy is a safe alternative for clinically stable patients. PROTOCOL: The early oral switch (EOS) domain of the S. aureus Network Adaptive Platform (SNAP) trial will assess early switch to oral antibiotics compared with continued IV treatment in clinically stable patients with SAB. The primary endpoint is 90-day all-cause mortality. Hospitalised SAB patients are assessed at platform day 7 +/- 2 (uncomplicated SAB) and day 14 +/-2 (complicated SAB) to determine their eligibility for randomisation to EOS (intervention) or continued IV treatment (current standard of care). DISCUSSION: Recruitment is occurring to the EOS domain of the SNAP trial. As of August 2023, 21% of all SNAP participants had been randomised to the EOS domain, a total of 264 participants across 77 centres, with an aim to recruit at least 1000 participants. We describe challenges and facilitators to enrolment in this domain to aid those planning similar trials.

Clinical trials for the prevention and treatment of COVID-19: current state of play.

Since coronavirus disease 2019 (COVID-19) emerged in Wuhan, China in December 2019 and spread around the world, over 1100 clinical studies have been registered globally on clinical trials registries, including over 500 randomised controlled trials. Such rapid development and launch of clinical trials is impressive but presents challenges, including the potential for duplication and competition. There is currently no known effective treatment for COVID-19. In order to focus on those studies most likely to influence clinical practice, we summarise the 31 currently registered randomised trials with a target sample size of at least 1000 participants. We have grouped these trials into four categories: prophylaxis; treatment of outpatients with mild COVID-19; treatment of hospitalised patients with moderate COVID-19; and treatment of hospitalised patients with moderate or severe disease. The most common therapeutic agent being trialled currently is hydroxychloroquine (24 trials with potential sample size of over 25 000 participants), followed by lopinavir-ritonavir (seven trials) and remdesevir (five trials) There are many candidate drugs in pre-clinical and early phase development, and these form a pipeline for future large clinical trials if current candidate therapies prove ineffective or unsafe.

Epidemiology, management and outcomes of Cryptococcus gattii infections: A 22-year cohort.

BACKGROUND: Cryptococcus gattii is a globally endemic pathogen causing disease in apparently immune-competent hosts. We describe a 22-year cohort study from Australia's Northern Territory to evaluate trends in epidemiology and management, and outcome predictors. METHODS: A retrospective cohort study of all C. gattii infections at the northern Australian referral hospital 1996-2018 was conducted. Cases were defined as confirmed (culture-positive) or probable. Demographic, clinical and outcome data were extracted from medical records. RESULTS: 45 individuals with C. gattii infection were included: 44 Aboriginal Australians; 35 with confirmed infection; none HIV positive out of 38 tested. Multifocal disease (pulmonary and central nervous system) occurred in 20/45 (44%). Nine people (20%) died within 12 months of diagnosis, five attributed directly to C. gattii. Significant residual disability was evident in 4/36 (11%) survivors. Predictors of mortality included: treatment before the year 2002 (4/11 versus 1/34); interruption to induction therapy (2/8 versus 3/37) and end-stage kidney disease (2/5 versus 3/40). Prolonged antifungal therapy was the standard approach in this cohort, with median treatment duration being 425 days (IQR 166-715). Ten individuals had adjunctive lung resection surgery for large pulmonary cryptococcomas (median diameter 6cm [range 2.2-10cm], versus 2.8cm [1.2-9cm] in those managed non-operatively). One died post-operatively, and 7 had thoracic surgical complications, but ultimately 9/10 (90%) treated surgically were cured compared with 10/15 (67%) who did not have lung surgery. Four patients were diagnosed with immune reconstitution inflammatory syndrome which was associated with age <40 years, brain cryptococcomas, high cerebrospinal fluid pressure, and serum cryptococcal antigen titre >1:512. CONCLUSION: C. gattii infection remains a challenging condition but treatment outcomes have significantly improved over 2 decades, with eradication of infection the norm. Adjunctive surgery for the management of bulky pulmonary C. gattii infection appears to increase the likelihood of durable cure and likely reduces the required duration of antifungal therapy.

The APPRISE Virtual Biobank for Infectious Diseases.

The Australian Partnership for Preparedness Research on InfectiouS disease Emergencies (APPRISE) has developed a virtual biobank to support infectious disease research in Australia. The virtual biobank (https://apprise.biogrid.org.au) integrates access to existing distributed infectious disease biospecimen collections comprising multiple specimen types, including plasma, serum, and peripheral blood mononuclear cells. Through the development of a common data model, multiple collections can be searched simultaneously via a secure web portal. The portal enhances the visibility and searchability of existing collections within their current governance and custodianship arrangements. The portal is easily scalable for integration of additional collections.

Immune profiling of SARS-CoV-2 infection during pregnancy reveals NK cell and γδ T cell perturbations.

Pregnancy poses a greater risk for severe COVID-19; however, underlying immunological changes associated with SARS-CoV-2 during pregnancy are poorly understood. We defined immune responses to SARS-CoV-2 in unvaccinated pregnant and nonpregnant women with acute and convalescent COVID-19, quantifying 217 immunological parameters. Humoral responses to SARS-CoV-2 were similar in pregnant and nonpregnant women, although our systems serology approach revealed distinct antibody and FcγR profiles between pregnant and nonpregnant women. Cellular analyses demonstrated marked differences in NK cell and unconventional T cell activation dynamics in pregnant women. Healthy pregnant women displayed preactivated NK cells and γδ T cells when compared with healthy nonpregnant women, which remained unchanged during acute and convalescent COVID-19. Conversely, nonpregnant women had prototypical activation of NK and γδ T cells. Activation of CD4+ and CD8+ T cells and T follicular helper cells was similar in SARS-CoV-2-infected pregnant and nonpregnant women, while antibody-secreting B cells were increased in pregnant women during acute COVID-19. Elevated levels of IL-8, IL-10, and IL-18 were found in pregnant women in their healthy state, and these cytokine levels remained elevated during acute and convalescent COVID-19. Collectively, we demonstrate perturbations in NK cell and γδ T cell activation in unvaccinated pregnant women with COVID-19, which may impact disease progression and severity during pregnancy.

Hepatitis B prevalence in women giving birth in the Northern Territory, Australia, 2005-2015.

Background: Hepatitis B virus (HBV) vaccination in the Northern Territory (NT) was funded for all Aboriginal and Torres Strait Islander newborns in 1988 and for all newborns in 1990. The prevalence of HBV in the Northern Territory was found to be higher in Aboriginal and Torres Strait Islander women than in non-Indigenous women across 2005-2010. We examined more recent data to assess whether the gap remains. Methods: We linked data from two routinely collected registries, the NT Perinatal Register and the NT Notifiable Diseases System, to investigate the prevalence of HBV infection, according to eligibility for infant HBV vaccination, in women giving birth during 2005-2015. Results: There were 22,781 women recorded as giving birth in public hospitals in the Northern Territory during 2005-2015. Hepatitis B virus prevalence was highest in Aboriginal and Torres Strait Islander (1.8%) and overseas-born women (1.8%). Among Aboriginal and Torres Strait Islander women, estimated hepatitis B virus prevalence was significantly higher in those born before the implementation of the vaccination program than in those born afterwards (2.4% versus 0.3%). Prevalence was highest amongst those living in very remote areas, both overall (2.2%) and within the birth cohort eligible for HBV vaccination. Conclusions: Hepatitis B virus prevalence in Northern Territory Aboriginal and Torres Strait Islander women appears to be declining as more individuals vaccinated as part of infant vaccination programs reach adulthood. Prevalence remains highest in remote areas, highlighting the importance of ongoing monitoring and of promoting vaccination in these regions.

ASCOT ADAPT study of COVID-19 therapeutics in hospitalised patients: an international multicentre adaptive platform trial.

BACKGROUND: SARS-CoV-2 infection is associated with a significant risk of hospitalisation, death, and prolonged impact on quality of life. Evaluation of new treatment options and optimising therapeutic management of people hospitalised with SARS-CoV-2 infection remains essential, but rapid changes in pandemic conditions and potential therapies have limited the utility of traditional approaches to randomised controlled trials. METHODS: ASCOT ADAPT is an international, investigator-initiated, adaptive platform, randomised controlled trial of therapeutics for non-critically ill patients hospitalised with COVID-19. The study design is open label and pragmatic. Potential participants are hospitalised adults with PCR confirmed, symptomatic, SARS-CoV-2 infection, within 14 days of symptom onset. Domains include antiviral, antibody and anticoagulant interventions, with a composite primary outcome of 28-day mortality or progression to intensive-care level respiratory or haemodynamic support. Initial interventions include intravenous nafamostat and variable dose anticoagulation. A range of secondary endpoints, and substudies for specific domains and interventions are outlined. DISCUSSION: This paper presents the trial protocol and management structure, including international governance, remote site monitoring and biobanking activities and provides commentary on ethical and pragmatic considerations in establishing the ASCOT ADAPT trial under pandemic conditions. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry (ACTRN12620000445976) and ClinicalTrials.gov (NCT04483960).

Threat of COVID-19 impacting on a quaternary healthcare service: a retrospective cohort study of administrative data.

OBJECTIVES: The threat of a pandemic, over and above the disease itself, may have significant and broad effects on a healthcare system. We aimed to describe the impact of the SARS-CoV-2 pandemic (during a relatively low transmission period) and associated societal restrictions on presentations, admissions and outpatient visits. DESIGN: We compared hospital activity in 2020 with the preceding 5 years, 2015-2019, using a retrospective cohort study design. SETTING: Quaternary hospital in Melbourne, Australia. PARTICIPANTS: Emergency department presentations, hospital admissions and outpatient visits from 1 January 2015 to 30 June 2020, n=896 934 episodes of care. INTERVENTION: In Australia, the initial peak COVID-19 phase was March-April. PRIMARY AND SECONDARY OUTCOME MEASURES: Separate linear regression models were fitted to estimate the impact of the pandemic on the number, type and severity of emergency presentations, hospital admissions and outpatient visits. RESULTS: During the peak COVID-19 phase (March and April 2020), there were marked reductions in emergency presentations (10 389 observed vs 14 678 expected; 29% reduction; p<0.05) and hospital admissions (5972 observed vs 8368 expected; 28% reduction; p<0.05). Stroke (114 observed vs 177 expected; 35% reduction; p<0.05) and trauma (1336 observed vs 1764 expected; 24% reduction; p<0.05) presentations decreased; acute myocardial infarctions were unchanged. There was an increase in the proportion of hospital admissions requiring intensive care (7.0% observed vs 6.0% expected; p<0.05) or resulting in death (2.2% observed vs 1.5% expected; p<0.05). Outpatient attendances remained similar (30 267 observed vs 31 980 expected; 5% reduction; not significant) but telephone/telehealth consultations increased from 2.5% to 45% (p<0.05) of total consultations. CONCLUSIONS: Although case numbers of COVID-19 were relatively low in Australia during the first 6 months of 2020, the impact on hospital activity was profound.

Antimicrobial stewardship in remote primary healthcare across northern Australia.

BACKGROUND: The high burden of infectious disease and associated antimicrobial use likely contribute to the emergence of antimicrobial resistance in remote Australian Aboriginal communities. We aimed to develop and apply context-specific tools to audit antimicrobial use in the remote primary healthcare setting. METHODS: We adapted the General Practice version of the National Antimicrobial Prescribing Survey (GP NAPS) tool to audit antimicrobial use over 2-3 weeks in 15 remote primary healthcare clinics across the Kimberley region of Western Australia (03/2018-06/2018), Top End of the Northern Territory (08/2017-09/2017) and far north Queensland (05/2018-06/2018). At each clinic we reviewed consecutive clinic presentations until 30 presentations where antimicrobials had been used were included in the audit. Data recorded included the antimicrobials used, indications and treating health professional. We assessed the appropriateness of antimicrobial use and functionality of the tool. RESULTS: We audited the use of 668 antimicrobials. Skin and soft tissue infections were the dominant treatment indications (WA: 35%; NT: 29%; QLD: 40%). Compared with other settings in Australia, narrow spectrum antimicrobials like benzathine benzylpenicillin were commonly given and the appropriateness of use was high (WA: 91%; NT: 82%; QLD: 65%). While the audit was informative, non-integration with practice software made the process manually intensive. CONCLUSIONS: Patterns of antimicrobial use in remote primary care are different from other settings in Australia. The adapted GP NAPS tool functioned well in this pilot study and has the potential for integration into clinical care. Regular stewardship audits would be facilitated by improved data extraction systems.

Staphylococcus aureus infections following knee and hip prosthesis insertion procedures.

BACKGROUND: Staphylococcus aureus is the most common and most important pathogen following knee and hip arthroplasty procedures. Understanding the epidemiology of invasive S. aureus infections is important to quantify this serious complication. METHODS: This nested retrospective cohort analysis included adult patients who had undergone insertion of knee or hip prostheses with clean or clean-contaminated wound class at 11 hospitals between 2003-2006. Invasive S. aureus infections, non-superficial incisional surgical site infections (SSIs) and blood stream infections (BSIs), were prospectively identified following each procedure. Prevalence rates, per 100 procedures, were estimated. RESULTS: 13,719 prosthetic knee (62%) and hip (38%) insertion procedures were performed. Of 92 invasive S. aureus infections identified, SSIs were more common (80%) than SSI and BSI (10%) or BSI alone (10%). The rate of invasive S. aureus infection/100 procedures was 0.57 [95% CI: 0.43-0.73] for knee insertion and 0.83 [95% CI: 0.61-1.08] for hip insertion. More than half (53%) were methicillin-resistant. Median time-to-onset of infection was 34 and 26 days for knee and hip insertion, respectively. Infection was associated with higher National Healthcare Safety Network risk index (p ≤ 0.0001). CONCLUSIONS: Post-operative invasive S. aureus infections were rare, but difficult-to-treat methicillin-resistant infections were relatively common. Optimizing preventative efforts may greatly reduce the healthcare burden associated with S. aureus infections.