Serious bacterial infections in neonates: improving reporting and case definitions

A Bayesian adaptive design for clinical trials of rare efficacy outcomes with multiple definitions

INTRODUCTION

Bayesian adaptive designs for clinical trials have gained popularity in the recent years due to the flexibility and efficiency that they offer. We consider the scenario where the outcome of interest comprises events with relatively low risk of occurrence and different case definitions resulting in varying control group risk assumptions. This is a scenario that occurs frequently for infectious diseases in global health research.

METHODS

We propose a Bayesian adaptive design that incorporates different case definitions of the outcome of interest that vary in stringency. A set of stopping rules are proposed where superiority and futility may be concluded with respect to different outcome definitions and therefore maintain a realistic probability of stopping in trials with low event rates. Through a simulation study, a variety of stopping rules and design configurations are compared.

RESULTS

The simulation results are provided in an interactive web application that allows the user to explore and compare the design operating characteristics for a variety of assumptions and design parameters with respect to different outcome definitions. The results for select simulation scenarios are provided in the article.

DISCUSSION

Bayesian adaptive designs offer the potential for maximizing the information learned from the data collected through clinical trials. The proposed design enables monitoring and utilizing multiple composite outcomes based on rare events to optimize the trial design operating characteristics.

Bacterial Epidemiology and Antimicrobial Resistance Profiles in Children Reported by the ISPED Program in China, 2016 to 2020

The Infectious Disease Surveillance of Pediatrics (ISPED) program was established in 2015 to monitor and analyze the trends of bacterial epidemiology and antimicrobial resistance (AMR) in children. Clinical bacterial isolates were collected from 11 tertiary care children’s hospitals in China in 2016 to 2020. Antimicrobial susceptibility testing was carried out using the Kirby-Bauer method or automated systems, with interpretation according to the Clinical and Laboratory Standards Institute 2019 breakpoints. A total of 288,377 isolates were collected, and the top 10 predominant bacteria were Escherichia coli, Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Klebsiella pneumoniae, Moraxella catarrhalis, Streptococcus pyogenes, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Acinetobacter baumannii. In 2020, the coronavirus disease 2019 (COVID-19) pandemic year, we observed a significant reduction in the proportion of respiratory tract samples (from 56.9% to 44.0%). A comparable reduction was also seen in the primary bacteria mainly isolated from respiratory tract samples, including S. pneumoniae, H. influenzae, and S. pyogenes. Multidrug-resistant organisms (MDROs) in children were commonly observed and presented higher rates of drug resistance than sensitive strains. The proportions of carbapenem-resistant K. pneumoniae (CRKP), carbapenem-resistant A. baumannii (CRAB), carbapenem-resistant P. aeruginosa (CRPA), and methicillin-resistant S. aureus (MRSA) strains were 19.7%, 46.4%%, 12.8%, and 35.0%, respectively. The proportions of CRKP, CRAB, and CRPA strains all showed decreasing trends between 2015 and 2020. Carbapenem-resistant Enterobacteriaceae (CRE) and CRPA gradually decreased with age, while CRAB showed the opposite trend with age. Both CRE and CRPA pose potential threats to neonates. MDROs show very high levels of AMR and have become an urgent threat to children, suggesting that effective monitoring of AMR and antimicrobial stewardship among children in China are required.

IMPORTANCE AMR, especially that involving multidrug-resistant organisms (MDROs), is recognized as a global threat to human health; AMR renders infections increasingly difficult to treat, constituting an enormous economic burden and producing tremendous negative impacts on patient morbidity and mortality rates. There are many surveillance programs in the world to address AMR profiles and MDRO prevalence in humans. However, published studies evaluating the overall AMR rates or MDRO distributions in children are very limited or are of mixed quality. In this study, we showed the bacterial epidemiology and resistance profiles of primary pathogens in Chinese children from 2016 to 2020 for the first time, analyzed MDRO distributions with time and with age, and described MDROs’ potential threats to children, especially low-immunity neonates. Our study will be very useful to guide antiinfection therapy in Chinese children, as well as worldwide pediatric patients.

Antibiotic prescribing in neonatal sepsis: an Australian nationwide survey

OBJECTIVE

To evaluate quality and variation in antibiotic prescribing for neonatal sepsis.

DESIGN

We analysed prescribing in hospitalised neonates using the National Antimicrobial Prescribing Survey in Australian neonates from 1 January 2014 to 31 December 2018.

SETTING

Data from antibiotic point prevalence surveys performed in hospitals, ranging from rural hospitals to tertiary paediatric and maternity hospitals within Australia.

PATIENTS

Admitted neonates <28 days of age from participating hospitals.

MAIN OUTCOME MEASURES

Variation and appropriateness in prescribing for neonatal sepsis and variation in dosing for gentamicin and benzylpenicillin across hospitals.

RESULTS

A total of 415 prescriptions among 214 neonates from 39 different hospitals were included. The majority of prescriptions (342, 82.4%) were for neonates <7 days of age. The most commonly prescribed antibiotics were gentamicin and benzylpenicillin, with 323 (77.8%) prescriptions. Dosing variability was substantial, with doses ranging from 2 to 8 mg/kg for gentamicin (median 5 mg/kg, IQR 4-5) and from 45 to 72 mg/kg for benzylpenicillin (median 60 mg/kg, IQR 50-60), although only 13 (3.2%) and 19 (4.6%) prescriptions were locally assessed as inappropriate or non-compliant with guidelines, respectively. At time of audit, 22% of antibiotics had been given for more than 48 hours and 9% more than 72 hours, although microbiologically confirmed infection was documented in only nine (4.2%) neonates.

CONCLUSIONS

Prescribing for neonatal sepsis was dominated by use of benzylpenicillin and gentamicin with substantial variation in dosing. A small minority had culture-confirmed infection. Efforts to standardise antibiotic dosing and duration for suspected neonatal sepsis are recommended.

Epidemiology of Early-onset Bacterial Neonatal Infections in Madagascar

BACKGROUND

Little is known about early-onset neonatal bacterial infections (EONBI) in Madagascar. Our aim was to determine their epidemiology to improve their management.

METHODS

Inborn neonates at risk for EONBI and admitted in the neonatal unit of 2 tertiary hospitals in Antananarivo, Madagascar, were included in a prospective study from April 2012 to March 2013. Using a clinical algorithm, blood culture, gastric fluid culture and C-reactive protein dosage were performed in newborns at high risk of infection, that is, peri partum fever, prematurity <35 weeks' gestation or birth weight <2000 g, or presenting with clinical signs of infection. EONBI was defined as a bacteremia occurring within the first week of life.

RESULTS

Among 307 neonates, 75 (24.4%) had an EONBI caused by 1 (n = 59) or 2 (n = 16) bacteria (91 isolates). Gram-negative bacteria were predominant (n = 62, 82.7%), including Enterobacter cloacae (n = 26), Klebsiella pneumoniae (n = 14), Escherichia coli (n = 7) and Proteus mirabilis (n = 2). Group B Streptococcus, Acinetobacter baumanii and Enterococcus sp. represented 3.6%, 8.2% and 12.1% of the isolates, respectively. All E. cloacae and 12/14 (85.7%) K. pneumoniae were extended-spectrum β-lactamase producers. At all, 41/91 (45.1%) bacteria were multidrug-resistant (MDR) and 34/75 (45.3%) newborns had an EONBI caused by an MDR bacteria. Neonatal asphyxia was the only factor associated with multidrug resistance (odds ratio: 4.52; CI: 1.20-16.94; P = 0.025). The EONBI-related mortality (n = 20/75, 26.7%) rose up to 38.2% (n = 13/34) in case of MDR bacteria.

CONCLUSIONS

The epidemiology of EONBIs in Madagascar is comparable to that found in many low-income countries. Prevention, including improvement of hygiene during resuscitation for neonatal asphyxia, is likely to be more effective in reducing EONBI-related morbidity and mortality than using new antibiotics to counter resistance.