Clinicopathologic conference: Bloodstream infection in an allogeneic hamatopoietic cell transplant: Thinking beyond the usual.

This case involves a 53-year-old female with concurrent acute myeloid leukemia (AML) and multiple myeloma. She underwent cytarabine and daunorubicin (7+3) induction chemotherapy followed by cytarabine (HiDAC) consolidation, with an early AML relapse requiring azacitidine and venetoclax therapy. She achieved complete remission and incomplete count recovery. Following fludarabine, melphalan, and thymoglobulin induction chemotherapy, she underwent an allogeneic stem cell transplant with failure to engraft, requiring autologous stem cell rescue, buffy coat, and granulocyte transfusions, eventually presenting with a diffuse skin rash consistent with Steven-Johnson syndrome and toxic epidermal necrolysis, persistent neutropenic fevers and positive blood cultures.

Neisseria gonorrhoeae vaccines: a contemporary overview.

Neisseria gonorrhoeae infection is an important public health issue, with an annual global incidence of 87 million. N. gonorrhoeae infection causes significant morbidity and can have serious long-term impacts on reproductive and neonatal health and may rarely cause life-threatening disease. Global rates of N. gonorrhoeae infection have increased over the past 20 years. Importantly, rates of antimicrobial resistance to key antimicrobials also continue to increase, with the United States Centers for Disease Control and Prevention identifying drug-resistant N. gonorrhoeae as an urgent threat to public health. This review summarizes the current evidence for N. gonorrhoeae vaccines, including historical clinical trials, key N. gonorrhoeae vaccine preclinical studies, and studies of the impact of Neisseria meningitidis vaccines on N. gonorrhoeae infection. A comprehensive survey of potential vaccine antigens, including those identified through traditional vaccine immunogenicity approaches, as well as those identified using more contemporary reverse vaccinology approaches, are also described. Finally, the potential epidemiological impacts of a N. gonorrhoeae vaccine and research priorities for further vaccine development are described.

Prevention and post-exposure management of occupational exposure to Ebola virus.

There have been significant advances in the prevention and management of Ebola virus disease (EVD) caused by Zaire Ebola virus (ZEBOV), including the development of two effective vaccines, rVSV-ZEBOV and Ad26.ZEBOV/MVA-BN-Filo. In addition, ZEBOV monoclonal antibodies have become first-line therapy for EVD. However, the 2022-23 outbreak of Sudan Ebola virus (SUDV) in Uganda has highlighted the gap in current therapies and vaccines, whose efficacy is uncertain against non-ZEBOV species. Health-care and laboratory staff working in EVD treatment centres or Ebola virus diagnostic and research laboratories face unique risks relating to potential occupational exposure to Ebola viruses. Given the substantial morbidity and mortality associated with EVD, facilities should have strategies in place to manage occupational exposures, including consideration of post-exposure therapies. In this Review, we discuss currently available evidence for prevention and post-exposure prophylaxis of EVD, including therapies currently under evaluation for SUDV.

Frequent screening for asymptomatic chlamydia and gonorrhoea infections in men who have sex with men: time to re-evaluate?

There is increasing debate regarding the harms and benefits of frequent asymptomatic screening for Chlamydia trachomatis and Neisseria gonorrhoeae in men who have sex with men (MSM). One concern is that frequent asymptomatic screening could result in increased antimicrobial resistance in an array of sexually acquired infections and other pathogens, due to selection pressure exerted by frequent broad-spectrum antimicrobial usage within some sexual networks. Here, we outline the harms and benefits of frequent C trachomatis and N gonorrhoeae screening in MSM in high-income settings and propose that screening frequency be reduced. We describe the evidence gaps that should be further explored to better understand the implications of reducing the frequency of asymptomatic C trachomatis and N gonorrhoeae screening in MSM and the surveillance systems that should be in place to prepare for such changes.

Laboratory diagnosis of HIV: a contemporary overview in the Australian context.

Over the past decade there have been technical advances in human immunodeficiency virus (HIV) assays and updates to testing regulations that have substantially changed the landscape of laboratory testing for HIV. In addition, there have been significant changes in the epidemiology of HIV in Australia in the context of highly effective contemporary biomedical treatment and prevention strategies. Here, we provide an update on contemporary issues for the laboratory detection and confirmation of HIV in Australia. These include (1) the impact of early treatment and biological prevention strategies on the serological and virological detection of HIV; (2) the updated national HIV laboratory case definition and its interaction with testing regulations, public health and clinical guidelines; and (3) novel strategies for the laboratory detection of HIV, including the incorporation of HIV nucleic acid amplification tests (NAATs) into testing algorithms. These developments present an opportunity to develop a nationally consistent contemporary HIV testing algorithm that would result in optimisation and standardisation of HIV testing in Australia.

Mpox diagnostics: Review of current and emerging technologies.

Mpox is a zoonotic disease caused by monkeypox virus (MPXV) from the Orthopoxvirus genus. Unprecedented transmission events have led to more than 70 000 cases reported worldwide by October 2022. The change in mpox epidemiology has raised concerns of its ability to establish endemicity beyond its traditional geographical locations. In this review, we discuss the current understanding of mpox virology and viral dynamics that are relevant to mpox diagnostics. A synopsis of the traditional and emerging laboratory technologies useful for MPXV detection and in guiding "elimination" strategies is outlined in this review. Importantly, development in MPXV genomics has rapidly advanced our understanding of the role of viral evolution and adaptation in the current outbreak.

Rapid culture of human keratinocytes in an autologous, feeder-free system with a novel growth medium.

BACKGROUND AIMS: The ability to culture human keratinocytes is beneficial in the treatment of skin injury and disease, as well as for testing chemicals in vitro as a substitute for animal testing. RESULTS: We have identified a novel culture medium for the rapid growth of keratinocytes from human skin. "Kelch's medium" supports keratinocyte growth that is as rapid as in the classical Rheinwald and Green method, but without the need for cholera toxin or xenogeneic feeder cells. It enables keratinocytes to out-compete co-cultured autologous fibroblasts so that separation of the epidermis from the dermis is no longer required before keratinocyte culture. Enzymatic digests of whole human skin can therefore be used to generate parallel cultures of autologous keratinocytes, fibroblasts and melanocytes simply by using different cell culture media. CONCLUSIONS: This new keratinocyte medium and the simplified manufacturing procedures it enables are likely to be beneficial in skin engineering, especially for clinical applications.

Utility of SARS-CoV-2 rapid antigen testing for patient triage in the emergency department: A clinical implementation study in Melbourne, Australia.

Background: Early, rapid detection of SARS-CoV-2 is essential in healthcare settings in order to implement appropriate infection control precautions and rapidly assign patients to care pathways. Rapid testing methods, such as SARS-CoV-2 rapid antigen testing (RAT) may improve patient care, despite a lower sensitivity than real-time PCR (RT-PCR) testing. Methods: Patients presenting to an Emergency Department (ED) in Melbourne, Australia, were risk-stratified for their likelihood of active COVID-19 infection, and a non-randomised cohort of patients were tested by both Abbott Panbio™ COVID-19 Ag test (RAT) and SARS-CoV-2 RT-PCR. Patients with a positive RAT in the 'At or High Risk' COVID-19 group were moved immediately to a COVID-19 ward rather than waiting for a RT-PCR result. Clinical and laboratory data were assessed to determine test performance characteristics; and length of stay in the ED was compared for the different patient cohorts. Findings: Analysis of 1762 paired RAT/RT-PCR samples demonstrated an overall sensitivity of 75.5% (206/273; 95% CI: 69·9-80·4) for the Abbott Panbio™ COVID-12 Ag test, with specificity of 100% (1489/1489; 95% CI: 99·8-100). Sensitivity improved with increasing risk for COVID-19 infection, from 72·4% (95% CI: 52·8-87·3) in the 'No Risk' cohort to 100% (95% CI: 29·2-100) in the 'High Risk' group. Time in the ED for the 'At/High Risk' group decreased from 421 minutes (IQR: 281, 525) for those with a positive RAT result to 274 minutes (IQR:140, 425) for those with a negative RAT result, p = 0.02. Interpretation: The positive predictive value of a positive RAT in this setting was high, allowing more rapid instigation of COVID-19 care pathways and an improvement in patient flow within the ED. Funding: Royal Melbourne Hospital, Melbourne, Australia.

Inhibitory Activity of Antibacterial Mouthwashes and Antiseptic Substances against Neisseria gonorrhoeae.

Improved treatment and prevention strategies, such as antimicrobial mouthwashes, may be important for addressing the public health threat of antimicrobial-resistant Neisseria gonorrhoeae. Here, we describe the activity of seven common antibacterial mouthwashes and antiseptics against N. gonorrhoeae isolates, incorporating the use of a human saliva test matrix. Our data demonstrate that antibacterial mouthwashes and antiseptics vary in their ability to inhibit the in vitro growth of N. gonorrhoeae and saliva may impact this inhibitory activity.

Ethics review of COVID-19 human challenge studies: A joint HRA/WHO workshop.

This report of a joint World Health Organization (WHO) and United Kingdom (UK) Health Research Authority (HRA) workshop discusses the ethics review of the first COVID-19 human challenge studies, undertaken in the midst of the pandemic. It reviews the early efforts of international and national institutions to define the ethical standards required for COVID-19 human challenge studies and create the frameworks to ensure rigorous and timely review of these studies. This report evaluates the utility of the WHO's international guidance document Key criteria for the ethical acceptability of COVID-19 human challenge studies (WHO Key Criteria) as a practical resource for the ethics review of COVID-19 human challenge studies. It also assesses the UK HRA's approach to these complex ethics reviews, including the formation of a Specialist Ad-Hoc Research Ethics Committee (REC) for COVID-19 Human Challenge Studies to review all current and future COVID-19 human challenge studies. In addition, the report outlines the reflections of REC members and researchers regarding the ethics review process of the first COVID-19 human challenge studies. Finally, it considers the potential ongoing scientific justification for COVID-19 human challenge studies, particularly in relation to next-generation vaccines and optimisation of vaccination schedules. Overall, there was broad agreement that the WHO Key Criteria represented an international consensus document that played a powerful role in setting norms and delineating the necessary conditions for the ethical acceptability of COVID-19 human challenge studies. Workshop members suggested that the WHO Key Criteria could be practically implemented to support researchers and ethics reviewers, including in the training of ethics committee members. In future, a wider audience may be engaged by the original document and potential additional materials, informed by the experiences of those involved in the first COVID-19 human challenge studies outlined in this document.

Consensus guidelines for antifungal stewardship, surveillance and infection prevention, 2021.

Invasive fungal diseases (IFD) are serious infections associated with high mortality, particularly in immunocompromised patients. The prescribing of antifungal agents to prevent and treat IFD is associated with substantial economic burden on the health system, high rates of adverse drug reactions, significant drug-drug interactions and the emergence of antifungal resistance. As the population at risk of IFD continues to grow due to the increased burden of cancer and related factors, the need for hospitals to employ antifungal stewardship (AFS) programmes and measures to monitor and prevent infection has become increasingly important. These guidelines outline the essential components, key interventions and metrics, which can help guide implementation of an AFS programme in order to optimise antifungal prescribing and IFD management. Specific recommendations are provided for quality processes for the prevention of IFD in the setting of outbreaks, during hospital building works, and in the context of Candida auris infection. Recommendations are detailed for the implementation of IFD surveillance to enhance detection of outbreaks, evaluate infection prevention and prophylaxis interventions and to allow benchmarking between hospitals. Areas in which information is still lacking and further research is required are also highlighted.

Invasive pulmonary aspergillosis in critically ill patients with COVID-19 in Australia: implications for screening and treatment.

We report four cases of invasive pulmonary aspergillus co-infection in patients with coronavirus disease 2019 (COVID-19) infection and acute respiratory distress syndrome requiring intensive care unit (ICU) admission. Aspergillus fumigatus and Aspergillus terreus were isolated, with early infection onset following ICU admission. Clinicians should be aware of invasive pulmonary aspergillosis in ICU patients with COVID-19 infection, particularly those receiving dexamethasone. We propose screening of these high-risk patients with twice-weekly fungal culture from tracheal aspirate and, if feasible, Aspergillus polymerase chain reaction. Diagnosis is challenging and antifungal treatment should be considered in critically ill patients who have new or worsening pulmonary changes on chest imaging and mycological evidence of infection.

Novel strategies for prevention and treatment of antimicrobial resistance in sexually-transmitted infections.

PURPOSE OF REVIEW: Antimicrobial resistance in sexually acquired infection (STI) pathogens is an important global public health threat. There is an urgent need for novel STI treatment and prevention strategies to tackle the rising incidence of STIs in high-income settings and the static progress in low- and middle-income settings over the past decade. The purpose of this review was to describe the research outlining the emergence of resistance in common STI pathogens and new strategies for their treatment and prevention. RECENT FINDINGS: Rates of STIs have dramatically increased over the past decade. Further, antimicrobial resistance to first-line agents among key STI pathogens continues to emerge globally. Recent findings demonstrate promising results regarding the efficacy of novel antimicrobial treatment strategies for these pathogens, including several new, repurposed and unique combinations of antimicrobials. In addition, a number of new biomedical prevention strategies, such as antibacterial mouthwash and doxycycline chemoprophylaxis, are being investigated as novel prevention strategies for bacterial STIs. SUMMARY: Significant progress has been made in the development of novel antimicrobials for the treatment of antimicrobial-resistant sexually acquired pathogens. However, due to the rapid development of resistance to antimicrobials demonstrated by these pathogens in the past, further research and development of effective prevention strategies should be prioritized.

The Chondrogenic Potential of First-Trimester and Term Placental Mesenchymal Stem/Stromal Cells.

OBJECTIVES: Mesenchymal stem/stromal cells (MSCs) are a well-established cell source for cartilage engineering, but challenges remain as differentiation often results in chondrocyte hypertrophy. Chondrogenic potential also varies with MSC source and donor age. We assessed the chondrogenic potential of first-trimester and term placental MSCs and compared their response to commonly used bone marrow MSCs (BM-MSCs). DESIGN: MSCs were isolated from first-trimester and term placentae. BM-MSCs were commercially obtained. Chondrogenesis was induced by micromass culture in commercial chondrogenic media for 7, 14, or 21 days. Pellets were assessed for glycosaminoglycan (GAG) content, and types I, II, and X collagen. Gene expression was profiled using Qiagen RT2 human MSC arrays. RESULTS: At day 0, first-trimester and term MSCs expression levels of many chondrogenic genes to BM-MSC after 21 days of culture. Only first trimester MSCs showed significant changes in chondrogenic gene expression during induction compared to day 0 undifferentiated MSCs (greater BMP4, KAT2B, and reduced GDF6 expression). Additionally, first-trimester MSCs showed significantly greater expression of ABCB1 (at days 14 and 21) and BMP4 (at days 7, 14, 21) compared with term MSCs. Both first-trimester and term pellets showed increased GAG content over time and term MSCs had significantly GAG greater compared with BM-MSCs at days 7 and 14. Type II collagen was present in all pellets but unlike BM-MSCs, type I collagen was not observed in first-trimester or term MSC pellets. CONCLUSIONS: These data highlight differences in BM-MSC and placental MSC chondrogenesis and demonstrate that placental MSCs may be an alternative cell source.

Adding saliva testing to oropharyngeal and deep nasal swab testing increases PCR detection of SARS-CoV-2 in primary care and children.

OBJECTIVE: To compare the concordance and acceptability of saliva testing with standard-of-care oropharyngeal and bilateral deep nasal swab testing for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in children and in general practice. DESIGN: Prospective multicentre diagnostic validation study. SETTING: Royal Children's Hospital, and two general practices (cohealth, West Melbourne; Cirqit Health, Altona North) in Melbourne, July-October 2020. PARTICIPANTS: 1050 people who provided paired saliva and oropharyngeal-nasal swabs for SARS-CoV-2 testing. MAIN OUTCOME MEASURES: Numbers of cases in which SARS-CoV-2 was detected in either specimen type by real-time polymerase chain reaction; concordance of results for paired specimens; positive percent agreement (PPA) for virus detection, by specimen type. RESULTS: SARS-CoV-2 was detected in 54 of 1050 people with assessable specimens (5%), including 19 cases (35%) in which both specimens were positive. The overall PPA was 72% (95% CI, 58-84%) for saliva and 63% (95% CI, 49-76%) for oropharyngeal-nasal swabs. For the 35 positive specimens from people aged 10 years or more, PPA was 86% (95% CI, 70-95%) for saliva and 63% (95% CI, 45-79%) for oropharyngeal-nasal swabs. Adding saliva testing to standard-of-care oropharyngeal-nasal swab testing increased overall case detection by 59% (95% CI, 29-95%). Providing saliva was preferred to an oropharyngeal-nasal swab by most participants (75%), including 141 of 153 children under 10 years of age (92%). CONCLUSION: In children over 10 years of age and adults, saliva testing alone may be suitable for SARS-CoV-2 detection, while for children under 10, saliva testing may be suitable as an adjunct to oropharyngeal-nasal swab testing for increasing case detection.

Multi-site assessment of rapid, point-of-care antigen testing for the diagnosis of SARS-CoV-2 infection in a low-prevalence setting: A validation and implementation study.

BACKGROUND: In Australia, COVID-19 diagnosis relies on RT-PCR testing which is relatively costly and time-consuming. To date, few studies have assessed the performance and implementation of rapid antigen-based SARS-CoV-2 testing in a setting with a low prevalence of COVID-19 infections, such as Australia. METHODS: This study recruited participants presenting for COVID-19 testing at three Melbourne metropolitan hospitals during a period of low COVID-19 prevalence. The Abbott PanBioTM COVID-19 Ag point-of-care test was performed alongside RT-PCR. In addition, participants with COVID-19 notified to the Victorian Government were invited to provide additional swabs to aid validation. Implementation challenges were also documented. FINDINGS: The specificity of the Abbott PanBioTM COVID-19 Ag test was 99.96% (95% CI 99.73 - 100%). Sensitivity amongst participants with RT-PCR-confirmed infection was dependent upon the duration of symptoms reported, ranging from 77.3% (duration 1 to 33 days) to 100% in those within seven days of symptom onset. A range of implementation challenges were identified which may inform future COVID-19 testing strategies in a low prevalence setting. INTERPRETATION: Given the high specificity, antigen-based tests may be most useful in rapidly triaging public health and hospital resources while expediting confirmatory RT-PCR testing. Considering the limitations in test sensitivity and the potential for rapid transmission in susceptible populations, particularly in hospital settings, careful consideration is required for implementation of antigen testing in a low prevalence setting. FUNDING: This work was funded by the Victorian Department of Health and Human Services. The funder was not involved in data analysis or manuscript preparation.