The Use of Long-term Antibiotics for Suppression of Bacterial Infections.

Suppressive antibiotic therapy is prescribed when a patient has an infection that is presumed to be incurable by a defined course of therapy or source control. The cohort receiving suppressive antibiotic therapy is typically highly comorbid and the infections often involve retained prosthetic material. In part due to a lack of clear guidelines regarding the use of suppressive antibiotics, and in part due to the complex nature of the infections in question, patients are often prescribed suppressive antibiotics for extremely long, if not indefinite, courses. The risks of prolonged antibiotic exposure in this context are not fully characterized, but they include adverse drug effects ranging from mild to severe, the development of antibiotic-resistant organisms, and perturbations of the gastrointestinal microbiome. In this narrative review we present the available evidence for the use of suppressive antibiotic therapy in 4 common indications, examine the gaps in the current literature, and explore the known and potential risks of this therapy. We also make suggestions for improving the quality of evidence in future studies, particularly by highlighting the need for a standardized term to describe the use of long courses of antibiotics to suppress hard-to-treat infections.

Cutting Edge: SARS-CoV-2 Infection Induces Robust Germinal Center Activity in the Human Tonsil.

Understanding the generation of immunity to SARS-CoV-2 in lymphoid tissues draining the site of infection has implications for immunity to SARS-CoV-2. We performed tonsil biopsies under local anesthesia in 19 subjects who had recovered from SARS-CoV-2 infection 24-225 d previously. The biopsies yielded >3 million cells for flow cytometric analysis in 17 subjects. Total and SARS-CoV-2 spike-specific germinal center B cells, and T follicular helper cells, were readily detectable in human tonsils early after SARS-CoV-2 infection, as assessed by flow cytometry. Responses were higher in samples within 2 mo of infection but still detectable in some subjects out to 7 mo following infection. We conclude the tonsils are a secondary lymphoid organ that develop germinal center responses to SARS-CoV-2 infection and could play a role in the long-term development of immunity.

Balancing Statistical Power and Risk in HIV Cure Clinical Trial Design.

BACKGROUND: Analytical treatment interruptions (ATI) are pauses of antiretroviral therapy (ART) in the context of human immunodeficiency virus (HIV) cure trials. They are the gold standard in determining if interventions being tested can achieve sustained virological control in the absence of ART. However, withholding ART comes with risks and discomforts to trial participant. We used mathematical models to explore how ATI study design can be improved to maximize statistical power, while minimizing risks to participants. METHODS: Using previously observed dynamics of time to viral rebound (TVR) post-ATI, we modelled estimates for optimal sample size, frequency, and ATI duration required to detect a significant difference in the TVR between control and intervention groups. Groups were compared using a log-rank test, and analytical and stochastic techniques. RESULTS: In placebo-controlled TVR studies, 120 participants are required in each arm to detect 30% difference in frequency of viral reactivation at 80% power. There was little statistical advantage to measuring viral load more frequently than weekly, or interrupting ART beyond 5 weeks in a TVR study. CONCLUSIONS: Current TVR HIV cure studies are underpowered to detect statistically significant changes in frequency of viral reactivation. Alternate study designs can improve the statistical power of ATI trials.

Human immunodeficiency virus and solid organ transplantation: a 15-year retrospective audit at a tertiary Australian transplant centre.

BACKGROUND: The incidence of end-stage organ disease in people living with human immunodeficiency virus (HIV) (PLWH) is increasing, as people live longer due to potent, tolerable antiretroviral therapy (ART). Consequently, the number of PLWH who would benefit from solid organ transplant (SOT) is rising. The SOT experience in PLWH in Australia remains limited. Aim To retrospectively review the outcomes for SOT in PLWH at our service, in Victoria, Australia. METHODS: A retrospective cohort study of PLWH undergoing SOT over a 15-year period was performed. Adult PLWH age >18 years were eligible and identified from the Victorian HIV Service database. Descriptive statistics were used to summarise baseline demographics and clinical data, and outcomes following SOT. RESULTS: Nine virologically suppressed PLWH underwent SOT from HIV-negative donors (five kidneys, two livers and two bilateral sequential lung transplants). All patients were male, with a median age of 57.3 years (interquartile range (IQR) = 54.3-60.1) and CD4 count of 485 (IQR = 342-835) at transplantation, and comorbidities were common at baseline. After a median follow up of 3.9 years (IQR = 2.7-7.6), 8 (89%) patents were alive, 7 (78%) had functioning grafts, although 5 (56%) experienced organ rejection. Infections were common. Two patients required modification to their ART due to significant drug-drug interactions prior to transplant, while 5 (56%) had modifications post-SOT. No patients experienced HIV virologic failure. CONCLUSION: PLWH with end-stage organ disease experience good clinical and functional outcomes and should be considered for SOT where indicated. However, multidisciplinary planning and care is essential to optimise care in this patient group.

Impact of SARS-CoV-2 transmission-based precautions on inpatient management of general medical patients.

This audit reviewed the impact on access to routine medical care and adverse outcomes in patients with suspected SARS-CoV-2 infection managed on a 'COVID-19' (CV) ward compared with a general medicine ward at Box Hill Hospital, Victoria. Data were collected at two time points to capture changes associated with onsite testing. We found no healthcare delays from admission to CV wards and observed faster exits from CV wards with improved testing efficiency. This critical finding is relevant as Victoria manages a third wave of infections.

Acceptability, motivation and the prospect of cure for people living with HIV and their healthcare providers in HIV cure-focused treatment interruption studies.

BACKGROUND: Analytical treatment interruptions (ATI) are commonly used clinical endpoints to assess interventions aimed at curing HIV or achieving antiretroviral therapy (ART)-free HIV remission. Understanding the acceptability of ATI amongst people living with HIV (PLHIV) and their HIV healthcare providers (HHP) is limited. METHODS: Two online surveys for PLHIV and HHP assessed awareness and acceptability of ATI, and understanding of the prospect for HIV cure in the future. Responses were collected from July 2017-January 2018. A descriptive analysis was performed and similar questions across the two surveys were compared using χ squared test. RESULTS: 442 PLHIV and 144 HHP completed the survey. 105/400 (26%) PLHIV had ever interrupted ART, 8% of which were in a clinical trial. Altruistic motivations were drivers of participation of PLHIV in cure related research. 81/135 (60%) HHP would support their patients wishing to enrol in an HIV cure-focused trial, but fewer would promote and allow such participation (25% and 31% respectively). Compared to HHP, PLHIV were more likely to believe that an HIV cure would be achievable within 10 years (55% vs. 19%, p < 0.001), had less awareness of ATI (46% vs. 62%, p < 0.001) and were less likely to have had experience of either participation or enrolment in an ATI study (5% vs. 18%, p < 0.001) CONCLUSION: PLHIV were more optimistic about the potential for HIV cure. HHP had more direct experience with HIV cure-focused studies. Educational strategies are required for both groups to increase understanding around ATIs in HIV cure research but should be tailored specifically to each group.

Life-long antimicrobial therapy: where is the evidence?

The decision to prescribe long-term or 'life-long' antibiotics in patients requires careful consideration by the treating clinician. While several guidelines exist to help assist in this decision, the long-term consequences are yet to be well studied. In this review, we aim to provide a summary of the available evidence for patient populations where long-term antibiotic therapy is currently recommended in clinical practice. We will also discuss the pitfalls of this approach, including medication adverse effects, economic cost and any possible contribution to the emerging epidemic of microbial resistance.

Myocarditis Caused by Human Parechovirus in Adult.

The infectious etiology of myocarditis often remains unidentified. We report a case of myocarditis associated with human parechovirus (HPeV) infection in an adult. HPeV is an emerging pathogen that can cause serious illness, including myocarditis, in adults. Testing for HPeV should be considered in differential diagnosis of myocarditis.

Surveillance of life-long antibiotics: a review of antibiotic prescribing practices in an Australian Healthcare Network.

BACKGROUND: The rise of antimicrobial use in the twentieth century has significantly reduced morbidity due to infection, however it has also brought with it the rise of increasing resistance. Some patients are on prolonged, if not "life-long" course of antibiotics. The reasons for this are varied, and include non-infectious indications. We aimed to study the characteristics of this potential source of antibiotic resistance, by exploring the antibiotic dispensing practices and describing the population of patients on long-term antibiotic therapy. METHODS: A retrospective cross-sectional study of antibiotic dispensing records was performed at a large university hospital-based healthcare network in Melbourne, Australia. Outpatient prescriptions were extracted from the hospital pharmacy database over a 6 month period in 2014. Medical records of these patients were reviewed to determine the indication for prescription, including microbiology, the intended duration, and the prescribing unit. A descriptive analysis was performed on this data. RESULTS: 66,127 dispensing episodes were reviewed. 202 patients were found to have been prescribed 1 or more antibiotics with an intended duration of 1 year or longer. 69/202 (34%) of these patients were prescribed prolonged antibiotics for primary prophylaxis in the setting of immunosuppression. 43/202 (21%) patients were prescribed long-term suppressive antibiotics for infections of thought incurable (e.g. vascular graft infections), and 34/43 (79%) were prescribed by Infectious Diseases doctors. 66/202 (33%) patients with cystic fibrosis were prescribed prolonged courses of macrolides or fluoroquinolones, by respiratory physicians. There was great heterogeneity noted in indications for prolonged antibiotic courses, as well as antibiotic agents utilised. CONCLUSION: Our study found that that continuous antibiotic therapy represented only a small proportion of overall antibiotic prescribing at our health network. Prolonged courses of antibiotics were used mainly to suppress infections thought incurable, but also as primary and secondary prophylaxis and as anti-inflammatory agents. More research is needed to understand the impact of long-term antibiotic consumption on both patients and microbial ecology.

Epstein-Barr virus encephalitis in solid organ transplantation.

Epstein-Barr virus (EBV) is typically associated with post transplant lymphoproliferative disease (PTLD) after solid organ and stem cell transplantation. However, it is rarely associated with neurological complications. We report a case of severe encephalitis complicating primary EBV infection six months post renal transplantation, and review the literature on EBV encephalitis in solid organ transplantation in adults. A 55-year-old male presented 6 months post cadaveric renal transplant with headache, fever and confusion. Neuroimaging was unremarkable, but an electroencephalogram was consistent with diffuse encephalopathy. EBV DNA was detected in both cerebrospinal fluid (13,177 copies/ml), and plasma (14,166 copies/ml). Management included reduction of immunosuppression, intravenous ganciclovir and intravenous immunoglobulin, and resulted in a reduction in EBV viral load in both plasma and cerebrospinal fluid. The patient made a full recovery with no long-term neurological deficits and preservation of the graft. This case highlights the importance of knowing donor and recipient EBV serostatus at time of transplant, and closely monitoring EBV DNA when there is a mismatch. Ganciclovir or valganciclovir prophylaxis has also been shown to reduce the incidence of primary EBV infection in renal transplantation in these recipients. Treatment options for EBV infection post-transplant include reduction of immunosuppression, antiviral therapy, IVIg, and monoclonal antibody therapy directed toward infected B lymphocytes.

Bacteroides pyogenes causing serious human wound infection from animal bites.

Bacteroides pyogenes is part of the normal oral flora of domestic animals. There is one previous report of human infection, with B. pyogenes bacteremia following a cat bite (Madsen 2011). We report seven severe human infections where B. pyogenes was identified by Bruker matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDTI-TOF MS), but not by VITEK MS and was misidentified by VITEK ANC card.

Human Wound Infection with Mannheimia glucosida following Lamb Bite.

Mannheimia spp. are veterinary pathogens that can cause mastitis and pneumonia in domestic cattle and sheep. While Mannheimia glucosida can be found as normal flora in oral and respiratory mucosa in sheep, there have been no reported cases of human infection with this organism.

Assessing understandings and perceptions of HIV cure among peer navigators and treatment officers in Australia.

HIV community peer navigators and treatment officers are important sources of information and guidance for people living with HIV. We conducted an anonymous online survey with members of the treatment outreach network of the Australian National Association of People Living with HIV. The survey explored understandings and acceptance of HIV cure research and was disseminated before and following an interactive workshop on HIV cure. We demonstrated an improvement in understandings of HIV cure science and increased willingness to participate in interventional clinical trials after the workshop. Concerns around interrupting HIV treatment and detrimental impacts on health were identified as barriers to participation. Altruism was a motivator to enrol in HIV cure trials, along with endorsement from a trusted member of community.

Impact of a TLR9 agonist and broadly neutralizing antibodies on HIV-1 persistence: the randomized phase 2a TITAN trial.

Inducing antiretroviral therapy (ART)-free virological control is a critical step toward a human immunodeficiency virus type 1 (HIV-1) cure. In this phase 2a, placebo-controlled, double-blinded trial, 43 people (85% males) with HIV-1 on ART were randomized to (1) placebo/placebo, (2) lefitolimod (TLR9 agonist)/placebo, (3) placebo/broadly neutralizing anti-HIV-1 antibodies (bNAbs) or (4) lefitolimod/bNAb. ART interruption (ATI) started at week 3. Lefitolimod was administered once weekly for the first 8 weeks, and bNAbs were administered twice, 1 d before and 3 weeks after ATI. The primary endpoint was time to loss of virologic control after ATI. The median delay in time to loss of virologic control compared to the placebo/placebo group was 0.5 weeks (P = 0.49), 12.5 weeks (P = 0.003) and 9.5 weeks (P = 0.004) in the lefitolimod/placebo, placebo/bNAb and lefitolimod/bNAb groups, respectively. Among secondary endpoints, viral doubling time was slower for bNAb groups compared to non-bNAb groups, and the interventions were overall safe. We observed no added benefit of lefitolimod. Despite subtherapeutic plasma bNAb levels, 36% (4/11) in the placebo/bNAb group compared to 0% (0/10) in the placebo/placebo group maintained virologic control after the 25-week ATI. Although immunotherapy with lefitolimod did not lead to ART-free HIV-1 control, bNAbs may be important components in future HIV-1 curative strategies. ClinicalTrials.gov identifier: NCT03837756 .

A Randomized Trial of Nafamostat for Covid-19.

BACKGROUND: Nafamostat mesylate is a potent in vitro antiviral agent that inhibits the host transmembrane protease serine 2 enzyme used by severe acute respiratory syndrome coronavirus 2 for cell entry. METHODS: This open-label, pragmatic, randomized clinical trial in Australia, New Zealand, and Nepal included noncritically ill hospitalized patients with coronavirus disease 2019 (Covid-19). Participants were randomly assigned to usual care or usual care plus nafamostat. The primary end point was death (any cause) or receipt of new invasive or noninvasive ventilation or vasopressor support within 28 days after randomization. Analysis was with a Bayesian logistic model in which an adjusted odds ratio <1.0 indicates improved outcomes with nafamostat. Enrollment was closed due to falling numbers of eligible patients. RESULTS: We screened 647 patients in 21 hospitals (15 in Australia, 4 in New Zealand, and 2 in Nepal) and enrolled 160 participants from May 2021 to August 2022. In the intention-to-treat population, the primary end point occurred in 8 (11%) of 73 patients with usual care and 4 (5%) of 82 with nafamostat. The median adjusted odds ratio for the primary end point for nafamostat was 0.40 (95% credible interval, 0.12 to 1.34) with a posterior probability of effectiveness (adjusted odds ratio <1.0) of 93%. For usual care compared with nafamostat, hyperkalemia occurred in 1 (1%) of 67 and 7 (9%) of 78 participants, respectively, and clinically relevant bleeding occurred in 1 (1%) of 73 and 7 (8%) of 82 participants. CONCLUSIONS: Among hospitalized patients with Covid-19, there was a 93% posterior probability that nafamostat reduced the odds of death or organ support. Prespecified stopping criteria were not met, precluding definitive conclusions. Hyperkalemia and bleeding were more common with nafamostat. (Funded by ASCOT and others; ClinicalTrials.gov number, NCT04483960.)

Long-Term Outcomes in Patients on Life-Long Antibiotics: A Five-Year Cohort Study.

BACKGROUND: Little is known about the impacts at an individual level of long-term antibiotic consumption. We explored health outcomes of long-term antibiotic therapy prescribed to a cohort of patients to suppress infections deemed incurable. METHODS: We conducted a 5-year longitudinal study of patients on long-term antibiotics at Monash Health, a metropolitan tertiary-level hospital network in Australia. Adults prescribed antibiotics for >12 months to suppress chronic infection or prevent recurrent infection were included. A retrospective review of medical records and a descriptive analysis was conducted. RESULTS: Twenty-seven patients were followed up during the study period, from 29 patients originally identified in Monash Health in 2014. Seven of the 27 patients (26%) died from causes unrelated to the suppressed infection, six (22%) ceased long-term antibiotic therapy and two (7%) required treatment modification. Fifteen (56%) were colonised with multiresistant microorganisms, including vancomycin resistant Enterococci, methicillin resistant Staphylococcus aureus, and carbapenem resistant Enterobacteriaciae. CONCLUSIONS: This work highlights the potential pitfalls of long-term antibiotic therapy, and the frailty of this cohort, who are often ineligible for definitive curative therapy.

Mitigation strategies to safely conduct HIV treatment research in the context of COVID-19.

INTRODUCTION: The International AIDS Society convened a multidisciplinary committee of experts in December 2020 to provide guidance and key considerations for the safe and ethical management of clinical trials involving people living with HIV (PLWH) during the SARS-CoV-2 pandemic. This consultation did not discuss guidance for the design of prevention studies for people at risk of HIV acquisition, nor for the programmatic delivery of antiretroviral therapy (ART). DISCUSSION: There is strong ambition to continue with HIV research from both PLWH and the research community despite the ongoing SARS-CoV-2 pandemic. How to do this safely and justly remains a critical debate. The SARS-CoV-2 pandemic continues to be highly dynamic. It is expected that with the emergence of effective SARS-CoV-2 prevention and treatment strategies, the risk to PLWH in clinical trials will decline over time. However, with the emergence of more contagious and potentially pathogenic SARS-CoV-2 variants, the effectiveness of current prevention and treatment strategies may be compromised. Uncertainty exists about how equally SARS-CoV-2 prevention and treatment strategies will be available globally, particularly for marginalized populations, many of whom are at high risk of reduced access to ART and/or HIV disease progression. All of these factors must be taken into account when deciding on the feasibility and safety of developing and implementing HIV research. CONCLUSIONS: It can be assumed for the foreseeable future that SARS-CoV-2 will persist and continue to pose challenges to conducting clinical research in PLWH. Guidelines regarding how best to implement HIV treatment studies will evolve accordingly. The risks and benefits of performing an HIV clinical trial must be carefully evaluated in the local context on an ongoing basis. With this document, we hope to provide a broad guidance that should remain viable and relevant even as the nature of the pandemic continues to develop.

Neurotoxicity with high-dose disulfiram and vorinostat used for HIV latency reversal.

OBJECTIVE: The aim of this study was to examine whether administering both vorinostat and disulfiram to people with HIV (PWH) on antiretroviral therapy (ART) is well tolerated and can enhance HIV latency reversal. DESIGN: Vorinostat and disulfiram can increase HIV transcription in PWH on ART. Together, these agents may lead to significant HIV latency reversal. METHODS: Virologically suppressed PWH on ART received disulfiram 2000 mg daily for 28 days and vorinostat 400 mg daily on days 8-10 and 22-24. The primary endpoint was plasma HIV RNA on day 11 relative to baseline using a single copy assay. Assessments included cell-associated unspliced RNA as a marker of latency reversal, HIV DNA in CD4+ T-cells, plasma HIV RNA, and plasma concentrations of ART, vorinostat, and disulfiram. RESULTS: The first two participants (P1 and P2) experienced grade 3 neurotoxicity leading to trial suspension. After 24 days, P1 presented with confusion, lethargy, and ataxia having stopped disulfiram and ART. Symptoms resolved by day 29. After 11 days, P2 presented with paranoia, emotional lability, lethargy, ataxia, and study drugs were ceased. Symptoms resolved by day 23. CA-US RNA increased by 1.4-fold and 1.3-fold for P1 and P2 respectively. Plasma HIV RNA was detectable from day 8 to 37 (peak 81 copies ml-1) for P2 but was not increased in P1 Antiretroviral levels were therapeutic and neuronal injury markers were elevated in P1. CONCLUSION: The combination of prolonged high-dose disulfiram and vorinostat was not safe in PWH on ART and should not be pursued despite evidence of latency reversal.

Favipiravir in early symptomatic COVID-19, a randomised placebo-controlled trial.

Background: Well tolerated antivirals administered early in the course of COVID-19 infection when the viremia is highest could prevent progression to severe disease. Favipiravir inhibits SARS-CoV-2 viral replication in vitro with evidence of clinical benefit in open label trials. Placebo controlled studies of people with early symptomatic COVID-19 with regular assessments of SARS-CoV-2 viral load can determine if it has an antiviral effect and improves clinical outcomes. Methods: People with PCR-confirmed COVID-19 and 5 days or less of symptoms were randomised 1:1 to favipiravir 1800 mg on day 1, then 800 mg twice daily or matched placebo for 14 days. SARS-CoV-2 viral load was quantitated from second daily self-collected nose-throat swabs while receiving study drug. The primary endpoint was time to virological cure defined as 2 successive swabs negative for SARS-CoV-2 by PCR and secondary outcomes were progression of disease severity, symptom resolution and safety. Findings: Between 31 July 2020 and 19 September 2021, 200 people were enrolled (199 in the community, 1 in hospital) with 190 receiving one or more doses of drug (modified intention to treat [mITT] population). There was no difference in time to virological cure (Log-rank p=0.6 comparing Kaplan Meier curves), progression to hospitalisation (14 favipiravir, 9 placebo; p=0.38), time to symptom resolution (cough, fever, sore throat) and there were no deaths. 51 people related an adverse event that was possibly drug related, but these were evenly distributed (n=24 favipiravir, n=27 placebo). Sensitivity analyses where the definition of virological cure was changed to: a single negative PCR, exclude datapoints based on the presence or absence of human DNA in the swab, a SARS-CoV-2 viral load < 300 copies/mL being considered negative all demonstrated no difference between arms. Interpretation: Favipiravir does not improve the time to virological cure or clinical outcomes and shows no evidence of an antiviral effect when treating early symptomatic COVID-19 infection. Funding: The study was supported in part by grants from the Commonwealth Bank Australia, the Lord Mayor's Charitable Foundation, Melbourne Australia and the Orloff Family Charitable Trust, Melbourne, Australia. JHM is supported by the Medical Research Future Fund, AYP, JT are supported by the Australian National Health and Medical Research Council.