Patterns of antibiotic use, pathogens and clinical outcomes in hospitalised neonates and young infants with sepsis in the NeoOBS global neonatal sepsis observational cohort study

Background Neonatal sepsis is a leading cause of child mortality, and increasing antimicrobial resistance threatens progress towards the Sustainable Development Goals. Evidence to guide antibiotic treatment for sepsis in neonates and young infants from randomized controlled trials or observational studies in low- and middle-income countries (LMICs) is scarce. We aimed to describe patterns of antibiotic use, pathogens and outcomes in LMIC hospital settings globally to inform future clinical trials on the management of neonatal sepsis. Methods & Findings Hospitalised infants aged <60 days with clinical sepsis were enrolled during 2018-2020 by 19 sites in 11 countries (mainly Asia and Africa). Prospective daily data was collected on clinical signs, supportive care, antibiotic treatment, microbiology and clinical outcome at 28 days. The study was observational, with no changes to routine clinical practice. 3204 infants were enrolled, with median birth weight 2500g (IQR 1400-3000) and postnatal age 5 days (IQR 2-15). Of 309 enrolled aged 28-60 days, 58.6% (n=181) were ex-preterm and/or a neonate at admission. 2215 (69%) infants had been in hospital since birth. 206 different empiric antibiotic combinations were used, which were structured into 5 groups that were developed from the World Health Organisation (WHO) AWaRe classification. 25.9% (n=814) of infants started a WHO first line regimen (Group 1 -Access, penicillin-based regimen) and 13.8% (n=432) started WHO second-line cephalosporins (cefotaxime/ceftriaxone) (Group 2- ‘Low’ Watch). The largest group (34.0%, n=1068) started a regimen providing partial extended-spectrum beta-lactamase (ESBL)/pseudomonal coverage (piperacillin-tazobactam, ceftazidime, or fluoroquinolone-based) (Group 3 – ‘Medium’ Watch), 18.0% (n=566) started a carbapenem (Group 4 – ‘High’ Watch), and 1.8% (n=57) started a Reserve antibiotic (Group 5, largely colistin-based). Predictors of starting non-WHO recommended regimens included lower birth weight, longer in-hospital stay, central vascular catheter use, previous culture positive sepsis or antibiotic exposure, previous surgery and greater sepsis severity. 728/2880 (25.3%) of initial regimens in Group 1-4 were escalated, mainly to carbapenems, and usually for clinical indications (n=480; 65.9%). 564 infants (17.6%) isolated a pathogen from their baseline blood culture, of which 62.9% (n=355) had a Gram-negative organism, predominantly Klebsiella pneumoniae (n=132) and Acinetobacter spp. (n=72). These leading Gram-negatives were both mostly resistant to WHO-recommended regimens, and also resistant to carbapenems in 32.6% and 71.4% of cases respectively. MRSA accounted for 61.1% of Staphylococcus aureus (n=54) isolates. Overall, 350/3204 infants died (11.3%; 95%CI 10.2-12.5%), with 17.7% case fatality rate among infants with a pathogen in baseline culture (95%CI 14.7-20.1%, n=99/564). Gram-negative infections accounted for 75/99 (75.8%) of pathogen-positive deaths, especially Klebsiella pneumoniae (n=28; 28.3%), and Acinetobacter spp. (n=24; 24.2%). Conclusion A very wide range of antibiotic regimens are now used to treat neonatal sepsis globally. There is common use of higher-level Watch antibiotics, frequent early switching and very infrequent de-escalation of therapy. Future hospital based neonatal sepsis trials will ideally need to account for the multiple regimens used as standard of care globally and include both empiric first line regimens and subsequent switching in the trial design. Why was this study done? What did the researchers do and find? What do these findings mean? ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was funded by the Global Antibiotic Research and Development Partnership (GARDP), made possible by Bill & Melinda Gates Foundation; German Federal Ministry of Education and Research; German Federal Ministry of Health; Government of the Principality of Monaco; the Indian Council for Medical Research; Japanese Ministry of Health, Labour and Welfare; Netherlands Ministry of Health, Welfare and Sport; South African Medical Research Council; UK Department of Health and Social Care (UK National Institute of Health Research and the Global Antimicrobial Resistance Innovation Fund GAMRIF); UK Medical research Council; Wellcome Trust. GARDP has also received core funding from the Leo Model Foundation; Luxembourg Ministry of Development Cooperation and Humanitarian Aid; Luxembourg Ministry of Health; Medecins Sans Frontieres; Swiss Federal Office of Public Health; UK Foreign, Commonwealth & Development Office (previously the UK Department for International Development). The authors had access to all study related data and had final responsibility for publication ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethical approval was obtained from St. Georges, University of London (SGUL) Research Ethics Committee and sites local, central or national ethics committees and other relevant local bodies, where required. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes Any data request should be made to GARDP initially.