ABSTRACT
In clinical settings with no commonly accepted standard-of-care, multiple treatment regimens are potentially useful, but some treatments may not be appropriate for some patients. A personalized randomized controlled trial (PRACTical) design has been proposed for this setting. For a network of treatments, each patient is randomized only among treatments which are appropriate for them. The aim is to produce treatment rankings that can inform clinical decisions about treatment choices for individual patients. Here we propose methods for determining sample size in a PRACTical design, since standard power-based methods are not applicable. We derive a sample size by evaluating information gained from trials of varying sizes. For a binary outcome, we quantify how many adverse outcomes would be prevented by choosing the top-ranked treatment for each patient based on trial results rather than choosing a random treatment from the appropriate personalized randomization list. In simulations, we evaluate three performance measures: mean reduction in adverse outcomes using sample information, proportion of simulated patients for whom the top-ranked treatment performed as well or almost as well as the best appropriate treatment, and proportion of simulated trials in which the top-ranked treatment performed better than a randomly chosen treatment. We apply the methods to a trial evaluating eight different combination antibiotic regimens for neonatal sepsis (NeoSep1), in which a PRACTical design addresses varying patterns of antibiotic choice based on disease characteristics and resistance. Our proposed approach produces results that are more relevant to complex decision making by clinicians and policy makers.
Subject(s)
Precision Medicine , Randomized Controlled Trials as Topic , Humans , Randomized Controlled Trials as Topic/methods , Sample Size , Precision Medicine/methods , Computer Simulation , Infant, Newborn , Sepsis/drug therapy , Models, StatisticalABSTRACT
Gram-negative bacteria (GNB) are a major cause of neonatal sepsis in low- and middle-income countries (LMICs). Although the World Health Organization (WHO) reports that over 80% of these sepsis deaths could be prevented through improved treatment, the efficacy of the currently recommended first- and second-line treatment regimens for this condition is increasingly affected by high rates of drug resistance. Here we assess three well known antibiotics, fosfomycin, flomoxef and amikacin, in combination as potential antibiotic treatment regimens by investigating the drug resistance and genetic profiles of commonly isolated GNB causing neonatal sepsis in LMICs. The five most prevalent bacterial isolates in the NeoOBS study (NCT03721302) are Klebsiella pneumoniae, Acinetobacter baumannii, E. coli, Serratia marcescens and Enterobacter cloacae complex. Among these isolates, high levels of ESBL and carbapenemase encoding genes are detected along with resistance to ampicillin, gentamicin and cefotaxime, the current WHO recommended empiric regimens. The three new combinations show excellent in vitro activity against ESBL-producing K. pneumoniae and E. coli isolates. Our data should further inform and support the clinical evaluation of these three antibiotic combinations for the treatment of neonatal sepsis in areas with high rates of multidrug-resistant Gram-negative bacteria.
Subject(s)
Acinetobacter baumannii , Anti-Bacterial Agents , Gram-Negative Bacteria , Gram-Negative Bacterial Infections , Klebsiella pneumoniae , Microbial Sensitivity Tests , Neonatal Sepsis , Humans , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/pharmacology , Neonatal Sepsis/microbiology , Neonatal Sepsis/drug therapy , Infant, Newborn , Gram-Negative Bacteria/drug effects , Gram-Negative Bacteria/genetics , Gram-Negative Bacteria/isolation & purification , Gram-Negative Bacterial Infections/drug therapy , Gram-Negative Bacterial Infections/microbiology , Acinetobacter baumannii/drug effects , Acinetobacter baumannii/isolation & purification , Acinetobacter baumannii/genetics , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/isolation & purification , Klebsiella pneumoniae/genetics , Amikacin/pharmacology , Amikacin/therapeutic use , Fosfomycin/pharmacology , Fosfomycin/therapeutic use , beta-Lactamases/genetics , beta-Lactamases/metabolism , Escherichia coli/drug effects , Escherichia coli/genetics , Escherichia coli/isolation & purification , Developing Countries , Drug Resistance, Multiple, Bacterial/genetics , Drug Therapy, Combination , Serratia marcescens/drug effects , Serratia marcescens/genetics , Serratia marcescens/isolation & purification , Enterobacter cloacae/drug effects , Enterobacter cloacae/genetics , Enterobacter cloacae/isolation & purification , Bacterial Proteins/genetics , Bacterial Proteins/metabolismABSTRACT
Background: Healthcare-associated infections account for substantial neonatal in-hospital mortality. Chlorhexidine gluconate (CHG) whole body skin application could reduce sepsis by lowering bacterial colonisation density, although safety and optimal application regimen is unclear. Emollients, including sunflower oil, may independently improve skin condition, thereby reducing sepsis. We aimed to inform which concentration and frequency of CHG, with or without emollient, would best balance safety and the surrogate marker of efficacy of reduction in bacterial colonisation, to be taken forward in a future pragmatic trial evaluating clinical outcomes of sepsis and mortality. Methods: In this multicentre, randomised, open-label, factorial pilot trial, neonates in two hospital sites (South Africa, Bangladesh) aged 1-6 days with gestational age ≥ 28 weeks and birthweight 1000-1999 g were randomly assigned in a factorial design stratified by site to three different concentrations of CHG (0.5%, 1%, and 2%), with or without emollient (sunflower oil) applied on working days vs alternate working days. A control arm received neither product. Caregivers were unblinded although laboratory staff were blinded to randomisation Co-primary outcomes were safety (change in neonatal skin condition score incorporating dryness, erythema, and skin breakdown) and efficacy in reducing bacterial colonisation density (change in total skin bacterial log10 CFU from randomisation to day-3 and day-8). The trial is registered at the ISRCTN registry, ISRCTN 69836999. Findings: Between Apr 12 2021 and Jan 18 2022, 208 infants were randomised and 198 were included in the final analysis. Skin condition scores were low with mean 0.1 (sd = 0.3; N = 208) at baseline, 0.1 (sd = 0.3; N = 199) at day 3 and 0.1 (sd = 0.3; N = 189) at day 8, with no evidence of differences between concentration (1% CHG vs 0.5% estimate = -0.3, 95% CI = (-1.2, 0.6), p = 0.55. 2% CHG vs 0.5% CHG estimate = 0.5 (-0.4, 1.4), p = 0.30), increasing frequency (estimate = -0.4; 95% CI = (-1.1, 0.4), p = 0.33), emollient (estimate = -0.5, (-1.2, 0.3), p = 0.23) or with control (estimate = -0.9, (-2.3, 0.4), p = 0.18). Mean log10 CFU was 4.9 (sd = 3.0; N = 208) at baseline, 6.3 (sd = 3.1; N = 198) at day 3 and 8.4 (sd = 2.6; N = 183) with no evidence of differences between concentration (1% CHG vs 0.5% estimate = -0.4; 95% CI = (-1.1, 0.23); p = 0.23. 2% CHG vs 0.5% CHG estimate = 0.0 (-0.6, 0.6), p = 0.96), with increasing frequency (estimate = -0.4; 95% CI = (-0.9, 0.2); p = 0.17), with emollient (estimate = 0.4, 95% CI = (-0.2, 0.9); p = 0.18) or with control (estimate = -0.2, 95% CI = (-1.3, 0.9); p = 0.73). By day-8, overall 158/183 (86%) of neonates were colonised with Enterobacterales, and 72/183 (39%) and 69/183 (9%) with Klebsiella spp resistant to third-generation cephalosporin and carbapenems, respectively. There were no CHG-related SAEs, emollient-related SAEs, grade 3 or 4 skin scores or grade 3 or 4 hypothermias. Interpretation: In this pilot trial of CHG with or without sunflower oil, no safety issues were identified, and further trials examining clinical outcomes are warranted. The relatively late start application of emollient, at a mean of 3.8 days of life, may have reduced the impact of the intervention although no subgroup effects were detected. There was no clear evidence in favour of a specific concentration of chlorhexidine, and there was rapid colonisation with Enterobacterales with frequent antimicrobial resistance, regardless of skin application regimen. Funding: The MRC Joint Applied Global Health award, the Global Antibiotic Research and Development Partnership (GARDP), MRC Clinical Trials Unit core funding (UKRI) and St. George's, University of London.
ABSTRACT
BACKGROUND: Australian states and territories used test-trace-isolate-quarantine (TTIQ) systems extensively in their response to the COVID-19 pandemic in 2020-2021. We report on an analysis of Australian case data to estimate the impact of test-trace-isolate-quarantine systems on SARS-CoV-2 transmission. METHODS: Our analysis uses a novel mathematical modelling framework and detailed surveillance data on COVID-19 cases including dates of infection and dates of isolation. First, we directly translate an empirical distribution of times from infection to isolation into reductions in potential for onward transmission during periods of relatively low caseloads (tens to hundreds of reported cases per day). We then apply a simulation approach, validated against case data, to assess the impact of case-initiated contact tracing on transmission during a period of relatively higher caseloads and system stress (up to thousands of cases per day). RESULTS: We estimate that under relatively low caseloads in the state of New South Wales (tens of cases per day), TTIQ contributed to a 54% reduction in transmission. Under higher caseloads in the state of Victoria (hundreds of cases per day), TTIQ contributed to a 42% reduction in transmission. Our results also suggest that case-initiated contact tracing can support timely quarantine in times of system stress (thousands of cases per day). CONCLUSION: Contact tracing systems for COVID-19 in Australia were highly effective and adaptable in supporting the national suppression strategy from 2020-21, prior to the emergence of the Omicron variant in November 2021. TTIQ systems were critical to the maintenance of the strong suppression strategy and were more effective when caseloads were (relatively) low.
Subject(s)
COVID-19 , Contact Tracing , Quarantine , SARS-CoV-2 , COVID-19/transmission , COVID-19/epidemiology , COVID-19/prevention & control , Humans , Australia/epidemiology , Models, Theoretical , Pandemics/prevention & control , New South Wales/epidemiologyABSTRACT
BACKGROUND: Antibiotic resistance is a significant public health problem and is responsible for high mortality in children and new-borns. Strengthening the rational use of antibiotics and improving the quality and access to existing antibiotics are important factors in the fight against antibiotic resistance. This study aims to provide knowledge on the use of antibiotics in children in resource-limited countries in order to identify problems and possible avenues for improvement of antibiotics use. METHODS: We conducted a retrospective study in July 2020 and collected quantitative clinical and therapeutic data on antibiotic prescriptions between January and December 2019 in 4 hospitals or health centres in both Uganda and Niger, respectively from January to December 2019. Semi-structured interviews and focus groups were conducted among healthcare personnel and carers for children under 17 years of age, respectively. RESULTS: A total of 1,622 children in Uganda and 660 children in Niger (mean age of 3.9 years (SD 4.43)) who received at least one antibiotic were included in the study. In hospital settings, 98.4 to 100% of children prescribed at least one antibiotic received at least one injectable antibiotic. Most hospitalized children received more than one antibiotic in both Uganda (52.1%) and Niger (71.1%). According to the WHO-AWaRe index, the proportion of prescriptions of antibiotics belonging to the Watch category was 21.8% (432/1982) in Uganda and 32.0% (371/1158) in Niger. No antibiotics from the Reserve category were prescribed. Health care provider's prescribing practices are rarely guided by microbiological analyses. Prescribers are faced with numerous constraints, such as lack of standard national guidelines, unavailability of essential antibiotics at the level of hospital pharmacies, the limited financial means of the families, and pressure to prescribe antibiotics from caregivers as well as from drug company representatives. The quality of some antibiotics provided by the National Medical Stores to the public and private hospitals has been questioned by some health professionals. Self-medication is a widespread practice for the antibiotic treatment of children for economic and access reasons. CONCLUSION: The study findings indicate that an intersection of policy, institutional norms and practices including individual caregiver or health provider factors, influence antibiotic prescription, administration and dispensing practices.
Subject(s)
Anti-Bacterial Agents , Hospitals, Private , Humans , Child , Child, Preschool , Niger , Uganda , Retrospective Studies , Anti-Bacterial Agents/therapeutic useABSTRACT
Neonatal sepsis is a significant cause of mortality and morbidity in low- and middle-income countries. To deliver high-quality data studies and inform future trials, it is crucial to understand the challenges encountered when managing global multi-centre research studies and to identify solutions that can feasibly be implemented in these settings. This paper provides an overview of the complexities faced by diverse research teams in different countries and regions, together with actions implemented to achieve pragmatic study management of a large multi-centre observational study of neonatal sepsis. We discuss specific considerations for enrolling sites with different approval processes and varied research experience, structures, and training. Implementing a flexible recruitment strategy and providing ongoing training were necessary to overcome these challenges. We emphasize the attention that must be given to designing the database and monitoring plans. Extensive data collection tools, complex databases, tight timelines, and stringent monitoring arrangements can be problematic and might put the study at risk. Finally, we discuss the complexities added when collecting and shipping isolates and the importance of having a robust central management team and interdisciplinary collaborators able to adapt easily and make swift decisions to deliver the study on time and to target. With pragmatic approaches, appropriate training, and good communication, these challenges can be overcome to deliver high-quality data from a complex study in challenging settings through a collaborative research network.
ABSTRACT
Neonatal invasive candidiasis (NIC) has significant morbidity and mortality. Reports have shown a different profile of those neonates affected with NIC and of fluconazole-resistant Candida spp. isolates in low- and middle-income countries (LMICs) compared to high-income countries (HICs). We describe the epidemiology, Candida spp. distribution, treatment, and outcomes of neonates with NIC from LMICs enrolled in a global, prospective, longitudinal, observational cohort study (NeoOBS) of hospitalized infants <60 days postnatal age with sepsis (August 2018-February 2021). A total of 127 neonates from 14 hospitals in 8 countries with Candida spp. isolated from blood culture were included. Median gestational age of affected neonates was 30 weeks (IQR: 28-34), and median birth weight was 1270 gr (interquartile range [IQR]: 990-1692). Only a minority had high-risk criteria, such as being born <28 weeks, 19% (24/127), or birth weight <1000 gr, 27% (34/127). The most common Candida species were C. albicans (n = 45, 35%), C. parapsilosis (n = 38, 30%), and Candida auris (n = 18, 14%). The majority of C. albicans isolates were fluconazole susceptible, whereas 59% of C. parapsilosis isolates were fluconazole-resistant. Amphotericin B was the most common antifungal used [74% (78/105)], followed by fluconazole [22% (23/105)]. Death by day 28 post-enrollment was 22% (28/127). To our knowledge, this is the largest multi-country cohort of NIC in LMICs. Most of the neonates would not have been considered at high risk for NIC in HICs. A substantial proportion of isolates was resistant to first choice fluconazole. Understanding the burden of NIC in LMIC is essential to guide future research and treatment guidelines.
Our study describes neonates from low- and middle-income countries with neonatal invasive candidiasis (NIC). Most of them were outside the groups considered at high risk for NIC described in high-income countries. Candida spp. epidemiology was also different. The mortality was high (22%). Further research in these settings is required.
Subject(s)
Candidiasis, Invasive , Fluconazole , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Birth Weight , Candida , Candida albicans , Candida parapsilosis , Candidiasis, Invasive/drug therapy , Candidiasis, Invasive/epidemiology , Candidiasis, Invasive/microbiology , Candidiasis, Invasive/veterinary , Developing Countries , Drug Resistance, Fungal , Fluconazole/pharmacology , Fluconazole/therapeutic use , Microbial Sensitivity Tests/veterinary , Prospective Studies , Humans , Infant, Newborn , InfantABSTRACT
OBJECTIVES: To describe the epidemiology and impact of Omicron BR.2.1, an emergent SARS-CoV-2 Omicron BA.2.75 sublineage displaying high fitness compared to other cocirculating subvariants in New South Wales, Australia. METHODS: From September 01 to November 26, 2022, 4971 SARS-CoV-2 consensus genomes from unique patients were generated, and correlated with international travel and reinfection history, and admission to the intensive care unit. RESULTS: BR.2.1 became the predominant variant by late November, and was responsible for a significantly higher proportion of community-acquired cases during the study period (55.1% vs 38.4%, P < 0.001). Reinfections (defined as occurring between 6 and 24 weeks after a prior diagnosis of COVID-19) were significantly higher among BR.2.1 compared to non-BR.2.1 infected persons (17.0% vs 6.0%, P < 0.001). BR.2.1 cases were also significantly younger compared to non-BR.2.1 (median age 48 years (interquartile range [IQR] 32) vs 53 years (IQR 32), P = 0.004). The proportion of patients admitted to the intensive care unit with BR.2.1 was not significantly higher than other subvariants (2.3% vs 2.0%, P = 0.717). CONCLUSION: Having emerged locally within New South Wales, BR.2.1 caused a significant number of SARS-CoV-2 reinfections, but with disease severity comparable with other currently circulating lineages. Given its rapid rise in prevalence, BR.2.1 has the potential to become established internationally.
Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Adult , New South Wales/epidemiology , Reinfection , COVID-19/diagnosis , COVID-19/epidemiology , Australia , Patient AcuityABSTRACT
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.
Subject(s)
Anti-Bacterial Agents , Vulnerable Populations , Adult , Infant, Newborn , Humans , Anti-Bacterial Agents/therapeutic use , World Health OrganizationABSTRACT
BACKGROUND: Annual mortality from neonatal sepsis is an estimated 430â000-680â000 infants globally, most of which occur in low- and middle-income countries (LMICs). The WHO currently recommends a narrow-spectrum ß-lactam (e.g. ampicillin) and gentamicin as first-line empirical therapy. However, available epidemiological data demonstrate high rates of resistance to both agents. Alternative empirical regimens are needed. Flomoxef and amikacin are two off-patent antibiotics with potential for use in this setting. OBJECTIVES: To assess the pharmacodynamics of flomoxef and amikacin in combination. METHODS: The pharmacodynamic interaction of flomoxef and amikacin was assessed in chequerboard assays and a 16-arm dose-ranged hollow-fibre infection model (HFIM) experiment. The combination was further assessed in HFIM experiments mimicking neonatal plasma exposures of clinically relevant doses of both drugs against five Enterobacterales isolates with a range of flomoxef/amikacin MICs. RESULTS: Flomoxef and amikacin in combination were synergistic in bacterial killing in both assays and prevention of emergence of amikacin resistance in the HFIM. In the HFIM assessing neonatal-like drug exposures, the combination killed 3/5 strains to sterility, (including 2/5 that monotherapy with either drug failed to kill) and failed to kill the 2/5 strains with flomoxef MICs of 32â mg/L. CONCLUSIONS: We conclude that the combination of flomoxef and amikacin is synergistic and is a potentially clinically effective regimen for the empirical treatment of neonatal sepsis in LMIC settings and is therefore suitable for further assessment in a clinical trial.
Subject(s)
Amikacin , Neonatal Sepsis , Infant , Infant, Newborn , Humans , Amikacin/pharmacology , Amikacin/therapeutic use , Neonatal Sepsis/drug therapy , Cephalosporins , Microbial Sensitivity Tests , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Delivery of Health CareABSTRACT
BACKGROUND: Neonatal sepsis is a serious bacterial infection of neonates, globally killing up to 680 000 babies annually. It is frequently complicated by antimicrobial resistance, particularly in low- and middle-income country (LMIC) settings with widespread resistance to the WHO's recommended empirical regimen of ampicillin and gentamicin. OBJECTIVES: We assessed the utility of flomoxef and fosfomycin as a potential alternative empirical regimen for neonatal sepsis in these settings. METHODS: We studied the combination in a 16-arm dose-ranged hollow-fibre infection model (HFIM) experiment and chequerboard assays. We further assessed the combination using clinically relevant regimens in the HFIM with six Enterobacterales strains with a range of flomoxef/fosfomycin MICs. RESULTS: Pharmacokinetic/pharmacodynamic modelling of the HFIM experimental output, along with data from chequerboard assays, indicated synergy of this regimen in terms of bacterial killing and prevention of emergence of fosfomycin resistance. Flomoxef monotherapy was sufficient to kill 3/3 strains with flomoxef MICs ≤0.5â mg/L to sterility. Three of three strains with flomoxef MICs ≥8â mg/L were not killed by fosfomycin or flomoxef monotherapy; 2/3 of these were killed with the combination of the two agents. CONCLUSIONS: These data suggest that flomoxef/fosfomycin could be an efficacious and synergistic regimen for the empirical treatment of neonatal sepsis in LMIC settings with prevalent antimicrobial resistance. Our HFIM results warrant further assessment of the flomoxef/fosfomycin combination in clinical trials.
Subject(s)
Fosfomycin , Neonatal Sepsis , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Cephalosporins , Drug Resistance, Bacterial , Fosfomycin/pharmacology , Fosfomycin/therapeutic use , Humans , Infant, Newborn , Microbial Sensitivity Tests , Neonatal Sepsis/drug therapyABSTRACT
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 (MICâ≤â0.25 mg/L) cover. However, less than one-quarter of neonates were predicted to receive efficacious coverage against Enterobacterales (MICâ≤â2 mg/L). The benefit of the ampicillin/gentamicin combination was limited, with only 2/23 E. coli clinical strains showing FIC indexâ<â0.5 (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.
Subject(s)
Neonatal Sepsis , Sepsis , Ampicillin/pharmacology , Ampicillin/therapeutic use , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Escherichia coli , Gentamicins/pharmacology , Gentamicins/therapeutic use , Humans , Infant, Newborn , Neonatal Sepsis/drug therapy , Sepsis/drug therapyABSTRACT
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.
Subject(s)
Fosfomycin , Neonatal Sepsis , Sepsis , Anti-Bacterial Agents/adverse effects , Child , Fosfomycin/adverse effects , Gentamicins , Humans , Infant , Infant, Newborn , Neonatal Sepsis/drug therapy , Sepsis/drug therapy , Sodium/therapeutic useABSTRACT
OBJECTIVES: Optimal treatment of carbapenem-resistant Gram-negative bacteria (CR-GNB) infections is uncertain because of the lack of good-quality evidence and the limited effectiveness of available antibiotics. The aim of this survey was to investigate clinicians' prescribing strategies for treating CR-GNB infections worldwide. METHODS: A 36-item questionnaire was developed addressing the following aspects of antibiotic prescribing: respondent's background, diagnostic and therapeutic availability, preferred antibiotic strategies and rationale for selecting combination therapy. Prescribers were recruited following the snowball sampling approach, and a post-stratification correction with inverse proportional weights was used to adjust the sample's representativeness. RESULTS: A total of 1012 respondents from 95 countries participated in the survey. Overall, 298 (30%) of the respondents had local guidelines for treating CR-GNB at their facility and 702 (71%) had access to Infectious Diseases consultation, with significant discrepancies according to country economic status: 85% (390/502) in high-income countries versus 59% (194/283) in upper-medium-income countries and 30% (118/196) in lower-middle-income countries/lower-income-countries). Targeted regimens varied widely, ranging from 40 regimens for CR-Acinetobacter spp. to more than 100 regimens for CR-Enterobacteriaceae. Although the majority of respondents acknowledged the lack of evidence behind this choice, dual combination was the preferred treatment scheme and carbapenem-polymyxin was the most prescribed regimen, irrespective of pathogen and infection source. Respondents noticeably disagreed around the meaning of 'combination therapy' with 20% (150/783) indicating the simple addition of multiple compounds, 42% (321/783) requiring the presence of in vitro activity and 38% (290/783) requiring in vitro synergism. CONCLUSIONS: Management of CR-GNB infections is far from being standardized. Strategic public health focused randomized controlled trials are urgently required to inform evidence-based treatment guidelines.
Subject(s)
Anti-Bacterial Agents , Carbapenems , Drug Resistance, Bacterial , Gram-Negative Bacterial Infections , Anti-Bacterial Agents/therapeutic use , Carbapenems/therapeutic use , Cross-Sectional Studies , Developed Countries , Developing Countries , Gram-Negative Bacteria , Gram-Negative Bacterial Infections/drug therapy , HumansABSTRACT
Neonatal sepsis causes up to an estimated 680,000 deaths annually worldwide, predominantly in low- and middle-income countries (LMICs). A significant and growing proportion of bacteria causing neonatal sepsis are resistant to multiple antibiotics, including the World Health Organization-recommended empiric neonatal sepsis regimen of ampicillin/gentamicin. The Global Antibiotic Research and Development Partnership is aiming to develop alternative empiric antibiotic regimens that fulfil several criteria: (1) affordable in LMIC settings; (2) activity against neonatal bacterial pathogens, including extended-spectrum ß-lactamase producers, gentamicin-resistant Gram-negative bacteria, and methicillin-resistant Staphylococcus aureus (MRSA); (3) a licence for neonatal use or extensive experience of use in neonates; and (4) minimal toxicities. In this review, we identify five antibiotics that fulfil these criteria: amikacin, tobramycin, fosfomycin, flomoxef, and cefepime. We describe the available characteristics of each in terms of mechanism of action, resistance mechanisms, clinical pharmacokinetics, pharmacodynamics, and toxicity profile. We also identify some knowledge gaps: (1) the neonatal pharmacokinetics of cefepime is reliant on relatively small and limited datasets, and the pharmacokinetics of flomoxef are also reliant on data from a limited demographic range and (2) for all reviewed agents, the pharmacodynamic index and target has not been definitively established for both bactericidal effect and emergence of resistance, with many assumed to have an identical index/target to similar class molecules. These five agents have the potential to be used in novel combination empiric regimens for neonatal sepsis. However, the data gaps need addressing by pharmacokinetic trials and pharmacodynamic characterisation.
Subject(s)
Methicillin-Resistant Staphylococcus aureus , Neonatal Sepsis , Sepsis , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacteria , Drug Resistance, Multiple, Bacterial , Humans , Infant, Newborn , Microbial Sensitivity Tests , Neonatal Sepsis/drug therapy , Sepsis/drug therapyABSTRACT
BACKGROUND: Effective treatment of sepsis due to carbapenem-resistant Gram-negative bacteria (CR-GNB) remains a challenge for clinicians worldwide. In recent years, the combination of antibiotics has become the preferred treatment strategy for CR-GNB infection. However, robust evidence to support this approach is lacking. This systematic review aimed at critically evaluating all available antibiotic options for CR-GNB sepsis with particular focus on combination. METHODS: We systematically searched published literature from January 1945 until December 2018 for observational comparative and non-comparative studies and randomized trials examining any antibiotic option for CR-GNB. Studies were included if reporting microbiologically-confirmed infection caused by Acinetobacter baumannii, Enterobacteriaceae/Klebsiella spp., or Pseudomonas aeruginosa, reporting at least one of the study outcomes, and definitive antibiotic treatment. Carbapenem-resistance was defined as phenotypically-detected in vitro resistance to at least one of the following carbapenems: doripenem, ertapenem, imipenem, meropenem. Each antibiotic regimen was classified as "defined" when at least the molecular class(es) composing the regimen was detailed. Primary outcomes were 30-day and attributable mortality. Bayesian network meta-analysis (NMA) approach was selected for quantitative synthesis to explore feasibility of pooling data on antibiotic regimens. RESULTS: A total of 6306 records were retrieved and 134 studies including 11,546 patients were included: 54 studies were on Acinetobacter, 52 on Enterobacteriaceae/Klebsiella, 21 on mixed Gram-negative, and 7 on Pseudomonas. Nine (7%) were RCTs; 19 prospective cohorts (14%), 89 (66%) retrospective, and 17 (13%) case series. Forty-one studies (31%) were multicentric. Qualitative synthesis showed an heterogeneous and scattered reporting of key-clinical and microbiological variables across studies. Ninety-two distinct antibiotic regimens were identified with 47 of them (51%, 5863 patients) not reporting any details on numbers, type, dosage and in vitro activity of the included antibiotic molecules. The NMAs could not be performed for any of the selected outcome given the presence of too many disconnected components. CONCLUSION: The existing evidence is insufficient to allowing for the formulation of any evidence-based therapeutic recommendation for CR-GNB sepsis. Future studies must provide a standardized definition of antibiotic regimen to drive recommendations for using combination of antibiotics that can be reliably applied to clinical practice.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Drug Resistance, Bacterial , Drug Therapy, Combination , Gram-Negative Bacteria , Gram-Negative Bacterial Infections/drug therapy , Acinetobacter baumannii , Carbapenems , Clinical Studies as Topic , Enterobacteriaceae , Humans , Pseudomonas aeruginosaABSTRACT
Antimicrobial resistance (particularly through extended-spectrum ß-lactamase and aminoglycoside-modifying enzyme production) in neonatal sepsis is a global problem, particularly in low- and middle-income countries, with significant mortality rates. High rates of resistance are reported for the current WHO-recommended first-line antibiotic regimen for neonatal sepsis, i.e., ampicillin and gentamicin. We assessed the utility of fosfomycin and amikacin as a potential alternative regimen to be used in settings of increasingly prevalent antimicrobial resistance. The combination was studied in a 16-arm dose-ranged hollow-fiber infection model (HFIM) experiment. The combination of amikacin and fosfomycin enhanced bactericidal activity and prevented the emergence of resistance, compared to monotherapy with either antibiotic. Modeling of the experimental quantitative outputs and data from checkerboard assays indicated synergy. We further assessed the combination regimen at clinically relevant doses in the HFIM with nine Enterobacterales strains with high fosfomycin and amikacin MICs and demonstrated successful kill to sterilization for 6/9 strains. From these data, we propose a novel combination breakpoint threshold for microbiological success for this antimicrobial combination against Enterobacterales strains, i.e., MICF × MICA < 256 (where MICF and MICA are the fosfomycin and amikacin MICs, respectively). Monte Carlo simulations predict that a standard fosfomycin-amikacin neonatal regimen would achieve >99% probability of pharmacodynamic success for strains with MICs below this threshold. We conclude that the combination of fosfomycin with amikacin is a viable regimen for the empirical treatment of neonatal sepsis and is suitable for further clinical assessment in a randomized controlled trial.
Subject(s)
Anti-Bacterial Agents , Fosfomycin , Neonatal Sepsis , Amikacin , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Drug Resistance, Bacterial , Fosfomycin/pharmacology , Fosfomycin/therapeutic use , Humans , Infant, Newborn , Microbial Sensitivity Tests , Neonatal Sepsis/drug therapyABSTRACT
BACKGROUND: Paediatric global antibiotic guidelines are inconsistent, most likely due to the limited pharmacokinetic and efficacy data in this population. We investigated factors underlying variation in antibiotic dosing using data from five global point prevalence surveys. METHODS & FINDINGS: Data from 3,367 doses of the 16 most frequent intravenous antibiotics administered to children 1 month-12 years across 23 countries were analysed. For each antibiotic, we identified standard doses given as either weight-based doses (in mg/kg/day) or fixed daily doses (in mg/day), and investigated the pattern of dosing using each strategy. Factors underlying observed variation in weight-based doses were investigated using linear mixed effects models. Weight-based dosing (in mg/kg/day) clustered around a small number of peaks, and all antibiotics had 1-3 standard weight-based doses used in 5%-48% of doses. Dosing strategy was more often weight-based than fixed daily dosing for all antibiotics apart from teicoplanin, which had approximately equal proportions of dosing attributable to each strategy. No strong consistent patterns emerged to explain the historical variation in actual weight-based doses used apart from higher dosing seen in central nervous system infections, and lower in skin and soft tissue infections compared to lower respiratory tract infections. Higher dosing was noted in the Americas compared to the European region. CONCLUSIONS: Antibiotic dosing in children clusters around a small number of doses, although variation remains. There is a clear opportunity for the clinical, scientific and public health communities to consolidate behind a consistent set of global antibiotic dosing guidelines to harmonise current practice and prioritise future research.
Subject(s)
Anti-Bacterial Agents/administration & dosage , International Health Regulations , Child , Child, Hospitalized/statistics & numerical data , Child, Preschool , Humans , Infant , MaleABSTRACT
The superiority of combination therapy for carbapenem-resistant Gram-negative bacilli (CR-GNB) infections remains controversial. In vitro models may predict the efficacy of antibiotic regimens against CR-GNB. A systematic review and meta-analysis was performed including pharmacokinetic/pharmacodynamic (PK/PD) and time-kill (TK) studies examining the in vitro efficacy of antibiotic combinations against CR-GNB [PROSPERO registration no. CRD42019128104]. The primary outcome was in vitro synergy based on the effect size (ES): high, ES ≥ 0.75, moderate, 0.35 < ES < 0.75; low, ES ≤ 0.35; and absent, ES = 0). A network meta-analysis assessed the bactericidal effect and re-growth rate (secondary outcomes). An adapted version of the ToxRTool was used for risk-of-bias assessment. Over 180 combination regimens from 136 studies were included. The most frequently analysed classes were polymyxins and carbapenems. Limited data were available for ceftazidime/avibactam, ceftolozane/tazobactam and imipenem/relebactam. High or moderate synergism was shown for polymyxin/rifampicin against Acinetobacter baumannii [ES = 0.91, 95% confidence interval (CI) 0.44-1.00], polymyxin/fosfomycin against Klebsiella pneumoniae (ES = 1.00, 95% CI 0.66-1.00) and imipenem/amikacin against Pseudomonas aeruginosa (ES = 1.00, 95% CI 0.21-1.00). Compared with monotherapy, increased bactericidal activity and lower re-growth rates were reported for colistin/fosfomycin and polymyxin/rifampicin in K. pneumoniae and for imipenem/amikacin or imipenem/tobramycin against P. aeruginosa. High quality was documented for 65% and 53% of PK/PD and TK studies, respectively. Well-designed in vitro studies should be encouraged to guide the selection of combination therapies in clinical trials and to improve the armamentarium against carbapenem-resistant bacteria.