Mediastinal Nontuberculous Mycobacterial Infection in Children: A Multidisciplinary Approach.

BACKGROUND: Mediastinal infections due to nontuberculous mycobacteria remain an exceedingly rare entity. Most cases in the published literature do not include pediatric patients. Due to their clinical infrequency, poor response to antimicrobial therapy and often precarious anatomical location, the optimal management of these lesions can be challenging. METHODS: Retrospective medical record review of 4 pediatric cases of mediastinal nontuberculous mycobacteria infection was undertaken. Each child presented with nonspecific respiratory symptoms, including significant acute airway obstruction and required a range of investigations to confirm the diagnosis. Nonresponsiveness to conservative measures and antimycobacterial therapy ultimately resulted in surgical intervention to obtain clinical improvement. RESULTS: All 4 children had extensive evaluation and multidisciplinary involvement in otolaryngology, respiratory medicine, pediatric surgery, infectious diseases and cardiothoracic surgery. They all eventually had their disease debulked via thoracotomy in addition to prolonged antimycobacterial therapy, with successful clinical outcomes. CONCLUSIONS: Mediastinal nontuberculous mycobacteria infections in the pediatric population are rare and diagnostically challenging. A high clinical suspicion should be maintained, and multidisciplinary input sought. Targeted surgery with adjuvant medical therapy can reduce disease burden with minimal long-term morbidity.

Tackling the threat of antimicrobial resistance in neonates and children: outcomes from the first WHO-convened Paediatric Drug Optimisation exercise for antibiotics.

Children and neonates are highly vulnerable to the impact of antimicrobial resistance. Substantial barriers are faced in relation to research and development of antibacterial agents for use in neonates, children, and adolescents aged yonger than 19 years, and focusing finite resources on the most appropriate agents for development and paediatric optimisation is urgently needed. In November and December, 2022, following the successes of previous similar disease-focused exercises, WHO convened the first Paediatric Drug Optimisation (PADO) exercise for antibiotics, aiming to provide a shortlist of antibiotics to be prioritised for paediatric research and development, especially for use in regions with the highest burden of disease attributable to serious bacterial infection. A range of antibiotics with either existing license for children or in clinical development in adults but with little paediatric data were considered, and PADO priority and PADO watch lists were formulated. This Review provides the background and overview of the exercise processes and its outcomes as well as a concise review of the literature supporting decision making. Follow-up actions to implement the outcomes from the PADO for antibiotics process are also summarised. This Review highlights the major beneficial influence the collaborative PADO process can have, both for therapeutic drug class and disease-specific themes, in uniting efforts to ensure children have access to essential medicines across the world.

Coverage gaps in empiric antibiotic regimens used to treat serious bacterial infections in neonates and children in Southeast Asia and the Pacific.

Background: High levels of antimicrobial resistance (AMR) are propagating deaths due to neonatal and paediatric infections globally. This is of particular concern in Southeast Asia and the Pacific, where healthcare resources are constrained and access to newer agents to treat multidrug-resistant pathogens is limited. Methods: To assess the coverage provided by commonly prescribed empiric antibiotic regimens for children in low- and middle-income countries in Southeast Asia and the Pacific, we built a weighted incidence syndromic combination antibiogram (WISCA), parameterised using data obtained from a systematic review of published literature incorporating WHO-defined SEARO and WPRO regions in Ovid MEDLINE, EMBASE, Global Health and PubMed. Susceptibility data for bacterial pathogens were extracted to provide coverage estimates for pre-specified antibiotics (aminopenicillins, gentamicin, third-generation cephalosporins and carbapenems), reported at the regional level. Findings: 6648 bacterial isolates from 11 countries across 86 papers were included in the Bayesian WISCA model, which weighted bacterial incidence and antimicrobial susceptibility of relevant isolates. Coverage provided by aminopenicillins in neonatal sepsis/meningitis was 26% (80% credible interval: 16-49) whilst gentamicin coverage was 45% (29-62). Third-generation cephalosporin coverage was only 29% (16-49) in neonatal sepsis/meningitis, 51% (38-64) in paediatric sepsis and 65% (51-77) in paediatric meningitis. Carbapenems were estimated to provide the highest coverage: 81% (65-90) in neonatal sepsis/meningitis, 83% (72-90) in paediatric sepsis and 79% (62-91) in paediatric meningitis. Interpretation: These findings reveal alarmingly high rates of resistance to commonly prescribed empirical therapies for neonatal and paediatric sepsis and meningitis in the Asia-Pacific region. Funding: This research was funded in whole, or in part, by the Wellcome Trust [220211]. For the purpose of Open Access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission. PCMW is supported by a National Health and Medical Research Council (NHMRC) Investigator Grant. NHMRC had no involvement in the design or conduct of the research.

Clinical, Genomic, and Immunological Characterization of RSV Surge in Sydney, Australia, 2022.

OBJECTIVES: The 2022 seasonal respiratory syncytial virus (RSV) epidemic in Sydney, Australia saw an unprecedented number of RSV detections. We aimed to characterize genomic and immunologic factors associated with the surge in RSV cases. METHODS: Whole genome sequences of RSV were generated from 264 RSV-infected infants and linked to case-matched clinical data from the 2022 southern hemisphere RSV season. We then performed an immunologic analysis of baseline RSV-specific humoral immunity in women of childbearing age before and throughout the coronavirus disease 2019 pandemic. RESULTS: Clinical analysis revealed a high burden of disease across patients of all health backgrounds. More than one-half of RSV-related health care visits by infants resulted in hospitalization, and one-quarter required high-flow respiratory support or a higher level of care. Viral phylogenetic analyses revealed that 2022 Sydney RSV sequences were closely related to viruses that had been circulating globally since 2017, including those detected in recent US outbreaks. Nonsynonymous mutations within the palivizumab and nirsevimab binding sites were detected at low frequencies. There was no difference in baseline RSV-neutralizing antibody titers between 2020 and 2022. CONCLUSIONS: Collectively, these findings suggest that neither the emergence of a novel RSV genotype nor hypothesized immune debt was associated with the surge of RSV cases and hospitalizations in 2022. Continued genomic and immunologic surveillance is required to further understand the factors driving outbreaks of RSV globally, and to inform guidelines for the rollout and ongoing use of recently developed immunotherapeutics and vaccines.

Metal Ion-Induced Large Fragment Deactivation: A Different Strategy for Site-Selectivity in a Complex Molecule.

Complex natural product functionalizations generally involve the use of highly engineered reagents, catalysts, or enzymes to react exclusively at a desired site through lowering of a select transition state energy. In this communication, we report a new, complementary strategy in which all transition states representing undesirable sites in a complex ionophore substrate are simultaneously energetically increased through the chelation of a metal ion to the large fragment we wish to neutralize. In the case of an electrophilic, radical based fluorination reaction, charge repulsion (electric field effects), induced steric effects, and electron withdrawal provide the necessary deactivation and proof of principle to afford a highly desirable natural product derivative. We envisage that many other electrophilic or charge based synthetic methods may be amenable to this approach as well.

Invasive aspergillosis in adult patients in Australia and New Zealand: 2017-2020.

Background: New and emerging risks for invasive aspergillosis (IA) bring the need for contemporary analyses of the epidemiology and outcomes of IA, in order to improve clinical practice. Methods: The study was a retrospective, multicenter, cohort design of proven and probable IA in adults from 10 Australasian tertiary centres (January 2017-December 2020). Descriptive analyses were used to report patients' demographics, predisposing factors, mycological characteristics, diagnosis and management. Accelerated failure-time model was employed to determine factor(s) associated with 90-day all-cause mortality (ACM). Findings: Of 382 IA episodes, 221 (in 221 patients) fulfilled inclusion criteria - 53 proven and 168 probable IA. Median patient age was 61 years (IQR 51-69). Patients with haematologic malignancies (HM) comprised 49.8% of cases. Fifteen patients (6.8%) had no pre-specified immunosuppression and eleven patients (5.0%) had no documented comorbidity. Only 30% of patients had neutropenia. Of 170 isolates identified, 40 (23.5%) were identified as non-Aspergillus fumigatus species complex. Azole-resistance was present in 3/46 (6.5%) of A. fumigatus sensu stricto isolates. Ninety-day ACM was 30.3%. HM (HR 1.90; 95% CI 1.04-3.46, p = 0.036) and ICU admission (HR 4.89; 95% CI 2.93-8.17, p < 0.001) but not neutropenia (HR 1.45; 95% CI 0.88-2.39, p = 0.135) were associated with mortality. Chronic kidney disease was also a significant predictor of death in the HM subgroup (HR 3.94; 95% CI 1.15-13.44, p = 0.028). Interpretation: IA is identified in high number of patients with mild/no immunosuppression in our study. The relatively high proportion of non-A. fumigatus species complex isolates and 6.5% azole-resistance rate amongst A. fumigatus sensu stricto necessitates accurate species identification and susceptibility testing for optimal patient outcomes. Funding: This work is unfunded. All authors' financial disclosures are listed in detail at the end of the manuscript.

Successful Use of Cefiderocol to Treat a Multidrug-resistant Stenotrophomonas maltophilia Ventilator-associated Pneumonia in an Extremely Preterm Neonate.

BACKGROUND: Ventilator-associated pneumonia (VAP) caries a morbidity and mortality risk in the preterm neonate, particularly in the context of rising global antimicrobial resistance driving infections due to multidrug-resistant Gram-negative bacteria. Cefiderocol, a siderophilic cephalosporin, has broad Gram-negative antimicrobial activity and central nervous system penetration and is used for the treatment of hospital-acquired pneumonia or VAP in adults. Scarce data exists on its use in neonates. CASE: A female neonate born at 26 + 6 weeks developed VAP at 21 days of life. She was commenced on corticosteroids, vancomycin and ceftazidime but continued to deteriorate. Sputum cultures yielded Stenotrophomonas maltophilia resistant to trimethoprim/sulfamethoxazole, ciprofloxacin and ceftazidime, with potential susceptibility to cefiderocol. Cerebrospinal fluid showed an elevated white cell count. In view of worsening respiratory and hemodynamic status, antibiotic treatment was changed to cefiderocol monotherapy at 30 mg/kg/dose every 8 hours. Within 72 hours of commencing cefiderocol, the neonate was successfully extubated to variable-flow continuous positive airway pressure and showed ongoing clinical improvement. CONCLUSIONS: Cefiderocol was integral for the care of our neonate without any immediate adverse safety consequences. We relied on dosing data from a conference abstract, due to the paucity of evidence on the use of novel antimicrobials. This lack of evidence is particularly concerning given preterm neonates are particularly vulnerable to infections with multidrug-resistant Gram-negative organisms due to their immature immune systems, prolonged hospital stay, repeated interventions and antimicrobial exposure.

A multicentre, retrospective audit of fosfomycin use for urinary tract infections in Australian children and adolescents.

BACKGROUND: Urinary tract infections (UTIs) due to MDR organisms are increasingly common. The lack of paediatric data on efficacious antibiotics makes UTI treatment particularly challenging. Data on the efficacy of fosfomycin use for UTI in children are variable. METHODS: We conducted a retrospective audit of children aged 0-18 years who were treated with fosfomycin for UTI at seven tertiary paediatric hospitals in Australia over a 7 year period, from 2014 to 2020. RESULTS: Ninety-one children with a median age of 5 years (range 2 months to 18 years) received oral fosfomycin for UTI. The majority (57/91, 63%) had one or more comorbidity, with the most common being renal tract anomalies (24/91, 26%). Fifty-nine (65%) had febrile UTI, 14/91 (15%) had pyelonephritis and 1/91 (1%) was bacteraemic. A majority (80/91, 88%) of urinary cultures had an ESBL-producing Gram-negative pathogen isolated. Fosfomycin susceptibility was evident in all 80 isolates tested. For uncomplicated UTI, the most common dose in children aged <1, 1-12 and >12 years was 1, 2 and 3 g, respectively. For complicated UTI, doses of 2 and 3 g were most common. The median duration of fosfomycin administration was 5 days (range 1-82). Clinical cure was achieved in 84/90 (93%); the six with treatment failure had underlying comorbidities. Overall, 2/91 (2%) children experienced drug-related adverse effects comprising gastrointestinal symptoms in both, which resolved after treatment discontinuation. CONCLUSIONS: Fosfomycin is well tolerated and associated with favourable treatment outcomes in children with UTI. Further research on the optimal dosing strategy is required.

Clinical and Epidemiologic Profile of Invasive Pneumococcal Disease in Australian Children Following the Relaxation of Nonpharmaceutical Interventions Against SARS-COV-2.

A global resurgence of invasive pneumococcal disease (IPD) has been noted in children. We provide a detailed clinical and epidemiological analysis of IPD in Australian children following relaxation of nonpharmaceutical interventions against coronavirus disease 2019, revealing significant morbidity and mortality-even in vaccinated children without known predisposing risk factors. Almost half of the IPD cases were caused by serotypes not covered by the 13-valent pneumococcal conjugate vaccine.

Predicting the causative pathogen among children with pneumonia using a causal Bayesian network.

BACKGROUND: Pneumonia remains a leading cause of hospitalization and death among young children worldwide, and the diagnostic challenge of differentiating bacterial from non-bacterial pneumonia is the main driver of antibiotic use for treating pneumonia in children. Causal Bayesian networks (BNs) serve as powerful tools for this problem as they provide clear maps of probabilistic relationships between variables and produce results in an explainable way by incorporating both domain expert knowledge and numerical data. METHODS: We used domain expert knowledge and data in combination and iteratively, to construct, parameterise and validate a causal BN to predict causative pathogens for childhood pneumonia. Expert knowledge elicitation occurred through a series of group workshops, surveys and one-on-one meetings involving 6-8 experts from diverse domain areas. The model performance was evaluated based on both quantitative metrics and qualitative expert validation. Sensitivity analyses were conducted to investigate how the target output is influenced by varying key assumptions of a particularly high degree of uncertainty around data or domain expert knowledge. RESULTS: Designed to apply to a cohort of children with X-ray confirmed pneumonia who presented to a tertiary paediatric hospital in Australia, the resulting BN offers explainable and quantitative predictions on a range of variables of interest, including the diagnosis of bacterial pneumonia, detection of respiratory pathogens in the nasopharynx, and the clinical phenotype of a pneumonia episode. Satisfactory numeric performance has been achieved including an area under the receiver operating characteristic curve of 0.8 in predicting clinically-confirmed bacterial pneumonia with sensitivity 88% and specificity 66% given certain input scenarios (i.e., information that is available and entered into the model) and trade-off preferences (i.e., relative weightings of the consequences of false positive versus false negative predictions). We specifically highlight that a desirable model output threshold for practical use is very dependent upon different input scenarios and trade-off preferences. Three commonly encountered scenarios were presented to demonstrate the potential usefulness of the BN outputs in various clinical pictures. CONCLUSIONS: To our knowledge, this is the first causal model developed to help determine the causative pathogen for paediatric pneumonia. We have shown how the method works and how it would help decision making on the use of antibiotics, providing insight into how computational model predictions may be translated to actionable decisions in practice. We discussed key next steps including external validation, adaptation and implementation. Our model framework and the methodological approach can be adapted beyond our context to broad respiratory infections and geographical and healthcare settings.

Antibiotics needed to treat multidrug-resistant infections in neonates.

Infections remain a leading cause of death in neonates. The sparse antibiotic development pipeline and challenges in conducting neonatal research have resulted in few effective antibiotics being adequately studied to treat multidrug-resistant (MDR) infections in neonates, despite the increasing global mortality burden caused by antimicrobial resistance. Of 40 antibiotics approved for use in adults since 2000, only four have included dosing information for neonates in their labelling. Currently, 43 adult antibiotic clinical trials are recruiting patients, compared with only six trials recruiting neonates. We review the World Health Organization (WHO) priority pathogens list relevant to neonatal sepsis and propose a WHO multiexpert stakeholder meeting to promote the development of a neonatal priority antibiotic development list. The goal is to develop international, interdisciplinary consensus for an accelerated neonatal antibiotic development programme. This programme would enable focused research on identified priority antibiotics for neonates to reduce the excess morbidity and mortality caused by MDR infections in this vulnerable population.

Les infections demeurent l'une des principales causes de décès chez les nouveau-nés. Les rares projets de développement d'antibiotiques et les défis posés par la recherche néonatale ont entraîné une pénurie d'antibiotiques efficaces spécialement étudiés pour traiter les infections multirésistantes (MR) chez les nouveau-nés, en dépit d'une mortalité galopante due à une résistance accrue aux antimicrobiens. Sur 40 antibiotiques autorisés pour les adultes depuis 2000, quatre à peine sont munis d'un étiquetage indiquant la posologie adaptée aux nouveau-nés. Actuellement, 43 essais cliniques portant sur des antibiotiques recrutent des patients du côté des adultes, contre six seulement du côté des nouveau-nés. Dans le présent document, nous passons en revue la liste prioritaire d'agents pathogènes établie par l'Organisation mondiale de la Santé (OMS) pour soigner la septicémie néonatale et proposons de réunir, sous l'égide de l'OMS, des parties prenantes issues de plusieurs domaines d'expertise afin de promouvoir la création d'une liste prioritaire de développement d'antibiotiques destinés aux nouveau-nés. Objectif: parvenir à un consensus international et interdisciplinaire visant à accélérer le programme de mise au point d'antibiotiques à usage néonatal. Ce programme permettrait d'orienter les recherches vers des antibiotiques identifiés comme prioritaires pour les nouveau-nés, en vue de faire baisser les taux de morbidité et de mortalité excessifs qu'engendrent les infections MR au sein de cette population vulnérable.

Las infecciones siguen siendo una de las principales causas de muerte en los recién nacidos. Debido al escaso desarrollo de los antibióticos y a las dificultades para llevar a cabo la investigación neonatal, son pocos los antibióticos eficaces que se estudian de manera adecuada para tratar las infecciones multirresistentes (MR) en los recién nacidos, a pesar de la creciente carga de mortalidad mundial causada por la resistencia a los antimicrobianos. De los 40 antibióticos aprobados para su uso en adultos desde el 2000, solo cuatro han incluido información sobre la dosis para recién nacidos en su etiquetado. En la actualidad, 43 ensayos clínicos con antibióticos para adultos están reclutando pacientes, en comparación con solo seis ensayos que reclutan recién nacidos. Se revisa la lista de patógenos prioritarios de la Organización Mundial de la Salud (OMS) relevantes para la sepsis neonatal y se propone una reunión de la OMS con múltiples expertos para promover el desarrollo de una lista de antibióticos prioritarios para los recién nacidos. El objetivo es desarrollar un consenso internacional e interdisciplinario para establecer un programa acelerado de desarrollo de antibióticos neonatales. Este programa permitiría centrar la investigación en los antibióticos prioritarios identificados para los recién nacidos con el fin de reducir el exceso de morbilidad y mortalidad causado por las infecciones MR en esta población vulnerable.

Monkeypox: A clinical update for paediatricians.

The global spread of human monkeypox disease, a zoonotic infection related to smallpox and endemic to West and Central Africa, presents serious challenges for health systems. As of July 2022, 14 533 cases have been reported world-wide, leading to designation as a Public Health Emergency of International Concern. Monkeypox disease is spread from animals to humans through infected lesions or fluids; human-human transmission occurs through fomites, droplets or direct contact. Illness is usually self-limiting, but severe disease can occur in specific groups - particularly children, and people who are immunocompromised or pregnant. Clinical presentation may include fever, lymphadenopathy and skin rash, but the rash may occur without other symptoms. Complications can include secondary bacterial infection of skin lesions, vision loss from corneal involvement, pneumonia, sepsis and encephalitis. Diagnosis of monkeypox requires consideration of epidemiological, clinical and laboratory findings, with sensitive history-taking, to elicit close contacts, critical. Supportive management is usually sufficient, but treatment options (where required) include antivirals and vaccinia immune globulin. A paucity of safety data for relevant antivirals may limit their use. There are two types of monkeypox vaccines: a replication-competent vaccinia vaccine, the use of which is logistically and clinically complex, and a replication-deficient modified vaccinia Ankara virus vaccine. Preparedness of health systems for addressing the current outbreak is constrained by historic underfunding for research, and compounded by stigma and discrimination against cases and affected communities. Key challenges in halting transmission include improving vaccine equity and countering discrimination against men who have sex with men to aid diagnosis and treatment.

Urinary tract infections in children: building a causal model-based decision support tool for diagnosis with domain knowledge and prospective data.

BACKGROUND: Diagnosing urinary tract infections (UTIs) in children in the emergency department (ED) is challenging due to the variable clinical presentations and difficulties in obtaining a urine sample free from contamination. Clinicians need to weigh a range of observations to make timely diagnostic and management decisions, a difficult task to achieve without support due to the complex interactions among relevant factors. Directed acyclic graphs (DAG) and causal Bayesian networks (BN) offer a way to explicitly outline the underlying disease, contamination and diagnostic processes, and to further make quantitative inference on the event of interest thus serving as a tool for decision support. METHODS: We prospectively collected data on children present to ED with suspected UTIs. Through knowledge elicitation workshops and one-on-one meetings, a DAG was co-developed with clinical domain experts (the Expert DAG) to describe the causal relationships among variables relevant to paediatric UTIs. The Expert DAG was combined with prospective data and further domain knowledge to inform the development of an application-oriented BN (the Applied BN), designed to support the diagnosis of UTI. We assessed the performance of the Applied BN using quantitative and qualitative methods. RESULTS: We summarised patient background, clinical and laboratory characteristics of 431 episodes of suspected UTIs enrolled from May 2019 to November 2020. The Expert DAG was presented with a narrative description, elucidating how infection, specimen contamination and management pathways causally interact to form the complex picture of paediatric UTIs. Parameterised using prospective data and expert-elicited parameters, the Applied BN achieved an excellent and stable performance in predicting Escherichia coli culture results, with a mean area under the receiver operating characteristic curve of 0.86 and a mean log loss of 0.48 based on 10-fold cross-validation. The BN predictions were reviewed via a validation workshop, and we illustrate how they can be presented for decision support using three hypothetical clinical scenarios. CONCLUSION: Causal BNs created from both expert knowledge and data can integrate case-specific information to provide individual decision support during the diagnosis of paediatric UTIs in ED. The model aids the interpretation of culture results and the diagnosis of UTIs, promising the prospect of improved patient care and judicious use of antibiotics.

COVID-19 in New South Wales children during 2021: severity and clinical spectrum.

OBJECTIVES: To describe the severity and clinical spectrum of coronavirus disease 2019 (COVID-19) in children during the 2021 New South Wales outbreak of the Delta variant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). DESIGN, SETTING: Prospective cohort study in three metropolitan Sydney local health districts, 1 June - 31 October 2021. PARTICIPANTS: Children under 16 years of age with positive SARS-CoV-2 nucleic acid test results admitted to hospital or managed by the Sydney Children's Hospital Network (SCHN) virtual care team. MAIN OUTCOME MEASURES: Age-specific SARS-CoV-2 infection frequency, overall and separately for SCHN virtual and hospital patients; rates of medical and social reason admissions, intensive care admissions, and paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 per 100 SARS-CoV-2 infections; demographic and clinical factors that influenced likelihood of hospital admission. RESULTS: A total of 17 474 SARS-CoV-2 infections in children under 16 were recorded in NSW, of whom 11 985 (68.6%) received SCHN-coordinated care, including 459 admitted to SCHN hospitals: 165 for medical reasons (1.38 [95% CI, 1.17-1.59] per 100 infections), including 15 admitted to intensive care, and 294 (under 18 years of age) for social reasons (2.45 [95% CI, 2.18-2.73] per 100 infections). In an analysis that included all children admitted to hospital and a random sample of those managed by the virtual team, having another medical condition (adjusted odds ratio [aOR], 7.42; 95% CI, 3.08-19.3) was associated with increased likelihood of medical admission; in univariate analyses, non-asthmatic chronic respiratory disease was associated with greater (OR, 9.21; 95% CI, 1.61-174) and asthma/viral induced wheeze with lower likelihood of admission (OR, 0.38; 95% CI, 0.18-0.78). The likelihood of admission for medical reasons declined from infancy to 5-11 years, but rose again for those aged 12-15 years. Sex and Indigenous status did not influence the likelihood of admission. CONCLUSION: Most SARS-CoV-2 infections (Delta variant) in children were asymptomatic or associated with mild disease. Hospitalisation was relatively infrequent, and most common for infants, adolescents, and children with other medical conditions. More children were hospitalised for social than for medical reasons.

Keeping It Real: Antibiotic Use Problems and Stewardship Solutions in Low- and Middle-income Countries.

Antimicrobial resistance is a global health threat and there is an urgent need to manage antibiotic use to slow its development. However, antimicrobial stewardship interventions in low- and middle-income countries (LMIC) have been limited in terms of their resourcing, feasibility and effectiveness in the face of greater challenges in child mortality. We sought to gather together examples of antibiotic use problems faced by clinicians in LMIC, many of which are unique to these settings, and real-world antimicrobial stewardship solutions identified, with the goal of learning broader lessons that might be applicable across LMIC.

Simultaneous pharmacokinetic/pharmacodynamic (PKPD) assessment of ampicillin and gentamicin in the treatment of neonatal sepsis.

OBJECTIVES: This study aimed to simultaneously investigate the pharmacokinetics of ampicillin and gentamicin, currently the WHO standard of care for treating neonatal sepsis. METHODS: Pharmacokinetic data were collected in 59 neonates receiving ampicillin and gentamicin for suspected or proven sepsis in the NeoFosfo trial (NCT03453177). A panel of 23 clinical Escherichia coli isolates from neonates with sepsis, resistant to either ampicillin, gentamicin or both, were tested for susceptibility using chequerboards. Pharmacokinetic/pharmacodynamic (PKPD) modelling and simulations were used to compare single-agent (EUCAST MIC) and combination (chequerboard MIC) target attainment with standard dosing regimens. RESULTS: A model was established that simultaneously estimated parameters of a one-compartment ampicillin model and a two-compartment gentamicin model. A common clearance for both drugs was used (6.89 L/h/70 kg) relating to glomerular filtration (CLGFR), with an additional clearance term added for ampicillin (5.3 L/h/70 kg). Covariate modelling included a priori allometric weight and post-menstrual age scaling of clearance. Further covariate relationships on renal clearance were postnatal age and serum creatinine.Simulation-based PKPD assessments suggest good Gram-positive (MIC ≤ 0.25 mg/L) cover. However, less than one-quarter of neonates were predicted to receive efficacious coverage against Enterobacterales (MIC ≤ 2 mg/L). The benefit of the ampicillin/gentamicin combination was limited, with only 2/23 E. coli clinical strains showing FIC index < 0.5 (synergy) and most in the range 0.5-1 (suggesting additivity). Simulations showed that feasible dosing strategies would be insufficient to cover resistant strains. CONCLUSIONS: PKPD simulations showed ampicillin and gentamicin combination therapy was insufficient to cover Enterobacterales, suggesting the need for alternative empirical treatment options for neonatal sepsis.

Randomised controlled trial of fosfomycin in neonatal sepsis: pharmacokinetics and safety in relation to sodium overload.

OBJECTIVE: To assess pharmacokinetics and changes to sodium levels in addition to adverse events (AEs) associated with fosfomycin among neonates with clinical sepsis. DESIGN: A single-centre open-label randomised controlled trial. SETTING: Kilifi County Hospital, Kenya. PATIENTS: 120 neonates aged ≤28 days admitted being treated with standard-of-care (SOC) antibiotics for sepsis: ampicillin and gentamicin between March 2018 and February 2019. INTERVENTION: We randomly assigned half the participants to receive additional intravenous then oral fosfomycin at 100 mg/kg two times per day for up to 7 days (SOC-F) and followed up for 28 days. MAIN OUTCOMES AND MEASURES: Serum sodium, AEs and fosfomycin pharmacokinetics. RESULTS: 61 and 59 infants aged 0-23 days were assigned to SOC-F and SOC, respectively. There was no evidence of impact of fosfomycin on serum sodium or gastrointestinal side effects. We observed 35 AEs among 25 SOC-F participants and 50 AEs among 34 SOC participants during 1560 and 1565 infant-days observation, respectively (2.2 vs 3.2 events/100 infant-days; incidence rate difference -0.95 events/100 infant-days (95% CI -2.1 to 0.20)). Four SOC-F and 3 SOC participants died. From 238 pharmacokinetic samples, modelling suggests an intravenous dose of 150 mg/kg two times per day is required for pharmacodynamic target attainment in most children, reduced to 100 mg/kg two times per day in neonates aged <7 days or weighing <1500 g. CONCLUSION AND RELEVANCE: Fosfomycin offers potential as an affordable regimen with a simple dosing schedule for neonatal sepsis. Further research on its safety is needed in larger cohorts of hospitalised neonates, including very preterm neonates or those critically ill. Resistance suppression would only be achieved for the most sensitive of organisms so fosfomycin is recommended to be used in combination with another antimicrobial. TRIAL REGISTRATION NUMBER: NCT03453177.