Risk for late-onset blood-culture proven sepsis in very-low-birth weight infants born small for gestational age: a large multicenter study from the German Neonatal Network

The Potential of Fecal Volatile Organic Compound Analysis for the Early Diagnosis of Late-Onset Sepsis in Preterm Infants: A Narrative Review

Early diagnosis and treatment of late-onset sepsis (LOS) is crucial for survival, but challenging. Intestinal microbiota and metabolome alterations precede the clinical onset of LOS, and the preterm gut is considered an important source of bacterial pathogens. Fecal volatile organic compounds (VOCs), formed by physiologic and pathophysiologic metabolic processes in the preterm gut, reflect a complex interplay between the human host, the environment, and microbiota. Disease-associated fecal VOCs can be detected with an array of devices with various potential for the development of a point-of-care test (POCT) for preclinical LOS detection. While characteristic VOCs for common LOS pathogens have been described, their VOC profiles often overlap with other pathogens due to similarities in metabolic pathways, hampering the construction of species-specific profiles. Clinical studies have, however, successfully discriminated LOS patients from healthy individuals using fecal VOC analysis with the highest predictive value for Gram-negative pathogens. This review discusses the current advancements in the development of a non-invasive fecal VOC-based POCT for early diagnosis of LOS, which may potentially provide opportunities for early intervention and targeted treatment and could improve clinical neonatal outcomes. Identification of confounding variables impacting VOC synthesis, selection of an optimal detection device, and development of standardized sampling protocols will allow for the development of a novel POCT in the near future.

Antimicrobial Resistance Pattern and Empirical Antibiotic Treatments in Neonatal Sepsis: A Retrospective, Single-Center, 12-Year Study

Neonatal sepsis is an important cause of morbidity and mortality in neonatal intensive care units (NICUs). Continuous evaluation of antimicrobial resistance (AMR) profiles is advised to implement antimicrobial stewardship (AMS) programs and establish effective empiric antibiotic protocols. AMS may reduce AMR in NICUs and improve sepsis outcomes. In this retrospective observational study, we report data on culture-positive neonatal sepsis, assessing differences after the implementation of an AMS program (2011-2016 vs. 2017-2022). A total of 215 positive bacterial cultures from 169 infants were retrieved, with 79 early-onset (36.7%) and 136 late-onset (63.3%) sepsis episodes. Frequent causative agents for early-onset sepsis were S. agalactiae and E. coli, all susceptible to empiric treatment. Late-onset sepsis was mainly caused by Enterobacterales and S. aureus. Aminoglycosides, cefotaxime, and piperacillin-tazobactam resistance among Enterobacterales was substantially low; S. aureus was mostly susceptible to oxacillin and vancomycin. There were no differences in mortality and multidrug-resistant pathogens rates between the two study periods. There were five episodes of fungal late-onset sepsis, mostly due to C. albicans, of which one was fatal. The microbial distribution pattern and AMR profiles overlapped with other European studies. Because susceptibility patterns are rapidly changing worldwide, with the emerging threat of Methicillin-resistant S. aureus and extended-spectrum beta-lactamases producers, infection prevention and control practices and AMS strategies require continuous optimization to limit selection pressure and AMR escalation.

Clinical profile of infants with late onset sepsis admitted in a North East Indian tertiary care center: insights into the uncharted

OBJECTIVES

To assess the clinical profile of infants with late onset sepsis admitted in a tertiary care hospital in North-East India.

METHODS

Prospective observational study was carried out in Department of Paediatrics, Regional Institute of Medical Sciences hospital during a period of 2 years (September 2019-August 2021).

RESULTS

A total of 109 patients were included in the study, of which 80 were community-acquired and 29 infants were hospital-acquired cases of late onset sepsis (LOS). The major risk factors were low socioeconomic status, prematurity, low birth weight, a history of intervention (mechanical ventilation, umbilical venous catheter, total parenteral nutrition, resuscitation) and lack of exclusive breastfeeding. The most common presenting features were decreased feeding, lethargy and respiratory distress. Blood cultures were positive in 33% of patients. Klebsiella was the most common hospital-acquired pathogen while Escherichia coli was the most common isolate in community-acquired cases. Thrombocytopenia was the most common complication. The in-hospital mortality rate was 13.7%.

CONCLUSION

Low socioeconomic status, low birth weight, prematurity, invasive interventions and lack of exclusive breastfeeding are the major risk factors of LOS. The clinical signs and symptoms are varied and subtle. The mean C-reactive protein in the hospital-acquired group was significantly higher as compared to the community-acquired group. There is substantial morbidity and mortality, resulting in an increased toll on resources, therefore, an aggressive preventive and treatment approach is recommended for late onset sepsis.

Late-onset sepsis in very preterm infants in Norway in 2009-2018: a population-based study

OBJECTIVE

To evaluate epidemiology and outcomes among very preterm infants (<32 weeks' gestation) with culture-positive and culture-negative late-onset sepsis (LOS).

DESIGN

Cohort study using a nationwide, population-based registry.

SETTING

21 neonatal units in Norway.

PARTICIPANTS

All very preterm infants born 1 January 2009-31 December 2018 and admitted to a neonatal unit.

MAIN OUTCOME MEASURES

Incidences, pathogen distribution, LOS-attributable mortality and associated morbidity at discharge.

RESULTS

Among 5296 very preterm infants, we identified 582 culture-positive LOS episodes in 493 infants (incidence 9.3%) and 282 culture-negative LOS episodes in 282 infants (incidence 5.3%). Extremely preterm infants (<28 weeks' gestation) had highest incidences of culture-positive (21.6%) and culture-negative (11.1%) LOS. The major causative pathogens were coagulase-negative staphylococci (49%), Staphylococcus aureus (15%), group B streptococci (10%) and Escherichia coli (8%). We observed increased odds of severe bronchopulmonary dysplasia (BPD) associated with both culture-positive (adjusted OR (aOR) 1.7; 95% CI 1.3 to 2.2) and culture-negative (aOR 1.6; 95% CI 1.3 to 2.6) LOS. Only culture-positive LOS was associated with increased odds of cystic periventricular leukomalacia (cPVL) (aOR 2.2; 95% CI 1.4 to 3.4) and severe retinopathy of prematurity (ROP) (aOR 1.8; 95% CI 1.2 to 2.8). Culture-positive LOS-attributable mortality was 6.3%, higher in Gram-negative (15.8%) compared with Gram-positive (4.1%) LOS, p=0.009. Among extremely preterm infants, survival rates increased from 75.2% in 2009-2013 to 81.0% in 2014-2018, p=0.005. In the same period culture-positive LOS rates increased from 17.1% to 25.6%, p<0.001.

CONCLUSIONS

LOS contributes to a significant burden of disease in very preterm infants and is associated with increased odds of severe BPD, cPVL and severe ROP.

Determinants of morbidity and mortality related to health care-associated primary bloodstream infections in neonatal intensive care units: a prospective cohort study from the SEPREVEN trial

Background

Health care-associated primary bloodstream infections (BSIs), defined as not secondary to an infection at another body site, including central line-associated BSI, are a leading cause of morbidity and mortality in patients in neonatal intensive care units (NICUs). Our objective was to identify factors associated with severe morbidity and mortality after these infections in neonates in NICUs.

Methods

This ancillary study of the SEPREVEN trial included neonates hospitalized ≥2 days in one of 12 French NICUs and with ≥ 1 BSI during the 20-month study period. BSIs (all primary and health care-associated) were diagnosed in infants with symptoms suggestive of infection and classified prospectively as possible (one coagulase-negative staphylococci (CoNS)-growing blood culture) or proven (two same CoNS, or ≥1 recognized pathogen-growing blood culture). BSI consequences were collected prospectively as moderate morbidity (antibiotic treatment alone) or severe morbidity/mortality (life-saving procedure, permanent damage, prolonged hospitalization, and/or death).

Results

Of 557 BSIs identified in 494 patients, CoNS accounted for 378/557 (67.8%) and recognized bacterial or fungal pathogens for 179/557 (32.1%). Severe morbidity/mortality was reported in 148/557 (26.6%) BSIs. Independent factors associated with severe morbidity/mortality were corrected gestational age <28 weeks (CGA) at infection (P < .01), fetal growth restriction (FGR) (P = .04), and proven pathogen-related BSI vs. CoNS-related BSI (P < .01). There were no differences in severe morbidity and mortality between proven and possible CoNS BSIs. In possible BSI, S. epidermidis was associated with a lower risk of severe morbidity than other CoNS (P < .01), notably S. capitis and S. haemolyticus.

Conclusions

In BSIs in the NICU, severe morbidity/mortality was associated with low CGA at infection, FGR, and proven pathogen-related BSIs. When only one blood culture was positive, severe morbidity/mortality were less frequent if it grew with S. epidermidis compared to other CoNS. Further studies to help distinguish real CoNS BSIs from contaminations are needed.

Study registration

ClinicalTrials.gov (NCT02598609).

Bacteriological profiles and antibiotic susceptibility of neonatal sepsis in a university hospital of Northern India

Context

Knowledge of epidemiology of bacterial isolates and their anti-biograms in hospital settings is necessary for prompt empirical anti-microbial therapy of neonatal sepsis.

Aims

To study risk factors, bacteriological profiles, and anti-biograms of blood culture isolates of both early and late onset neonatal sepsis.

Settings and Design

It is a prospective observational study conducted from January 2020 till July 2021 at our tertiary care center.

Material and Methods

Neonates (0-28 days) admitted to this neonatal intensive care unit clinically suspected with sepsis were subjected to blood cultures, and the isolates were identified both biochemically and by the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry system. Antibiotic susceptibility testing (AST) was performed as per CLSI guidelines.

Statistical Analysis

Chi-square test was used.

Results

Out of 280 suspected cases of neonatal sepsis, 43 (15.3%) cases showed positive blood culture. Of these, the majority (30, 69.8%) had late-onset neonatal sepsis. Major pre-disposing risk factors were pre-term birth and a low birth weight (26, 60.5%). Gram-negative bacteria and Gram-positive bacteria were isolated in 25 (58.1%) and 18 (41.9%) blood cultures, respectively. Klebsiella pneumoniae (37.5%) was the most predominant pathogen in both early-onset (23.1%) and late-onset (46.7%) sepsis. Coagulase negative Staphylococcus (34.8%) was the second most common organism and was more common in late onset (23.2%) neonatal sepsis. A high level of antibiotic resistance was noted in Klebsiella pneumoniae isolates, even to amikacin (76.5%) and carbapenems (66.7%).

Conclusion

Increased resistance in bacterial isolates of neonatal sepsis emphasizes the need of AST of bacterial isolates for proper antibiotic administration.

Preterm infants at low risk for early-onset sepsis differ in early fecal microbiome assembly

Antibiotics are administered near-universally to very low birth weight (VLBW) infants after birth for suspected early-onset sepsis (EOS). We previously identified a phenotypic group of VLBW infants, referred to as low-risk for EOS (LRE), whose risk of EOS is low enough to avoid routine antibiotic initiation. In this cohort study, we compared 18 such infants with 30 infants categorized as non-LRE to determine if the lower risk of pathogen transmission at birth is accompanied by differences in microbiome acquisition and development. We did shotgun metagenomic sequencing of 361 fecal samples obtained serially. LRE infants had a higher human-to-bacterial DNA ratio than non-LRE infants in fecal samples on days 1-3 after birth, confirming lower bacterial acquisition among LRE infants. The microbial diversity and composition in samples from days 4-7 differed between the groups with a predominance of Staphylococcus epidermidis in LRE infants and Enterobacteriaceae sp. in non-LRE infants. Compositional differences were congruent with the distribution of virulence factors and antibiotic resistant genes. After the first week, the overall composition was similar, but changes in relative abundance for several taxa with increasing age differed between groups. Of the nine late-onset bacteremia episodes, eight occurred in non-LRE infants. Species isolated from the blood culture was detected in the pre-antibiotic fecal samples of the infant for all episodes, though these species were also found in infants without bacteremia. In conclusion, LRE infants present a distinct pattern of microbiome development that is aligned with their low risk for EOS. Further investigation to determine the impact of these differences on later outcomes such as late-onset bacteremia is warranted.

Clinical and laboratory factors associated with neonatal sepsis mortality at a major Vietnamese children's hospital

Sepsis is a major cause of neonatal mortality and children born in low- and middle-income countries (LMICs) are at greater risk of severe neonatal infections than those in higher-income countries. Despite this disparity, there are limited contemporaneous data linking the clinical features of neonatal sepsis with outcome in LMICs. Here, we aimed to identify factors associated with mortality from neonatal sepsis in Vietnam. We conducted a prospective, observational study to describe the clinical features, laboratory characteristics, and mortality rate of neonatal sepsis at a major children's hospital in Ho Chi Minh City. All in-patient neonates clinically diagnosed with probable or culture-confirmed sepsis meeting inclusion criteria from January 2017 to June 2018 were enrolled. We performed univariable analysis and logistic regression to identify factors independently associated with mortality. 524 neonates were recruited. Most cases were defined as late-onset neonatal sepsis and were hospital-acquired (91.4% and 73.3%, respectively). The median (IQR) duration of hospital stay was 23 (13-41) days, 344/524 (65.6%) had a positive blood culture (of which 393 non-contaminant organisms were isolated), and 69/524 (13.2%) patients died. Coagulase-negative staphylococci (232/405; 57.3%), Klebsiella spp. (28/405; 6.9%), and Escherichia coli (27/405; 6.7%) were the most isolated organisms. Sclerema (OR = 11.4), leukopenia <4,000/mm3 (OR = 7.8), thrombocytopenia <100,000/mm3 (OR = 3.7), base excess < -20 mEq/L (OR = 3.6), serum lactate >4 mmol/L (OR = 3.4), extremely low birth weight (OR = 3.2), and hyperglycaemia >180 mg/dL (OR = 2.6) were all significantly (p<0.05) associated with mortality. The identified risk factors can be adopted as prognostic factors for the diagnosis and treatment of neonatal sepsis and enable early risk stratification and interventions appropriate to reduce neonatal sepsis in LMIC settings.

A Yersiniabactin-producing Klebsiella aerogenes Strain Causing an Outbreak in an Austrian Neonatal Intensive Care Unit

BACKGROUND

Yersiniabactin, a siderophore with a high affinity to iron, has been described as a potential virulence factor in Enterobacteriaceae. Klebsiella aerogenes is a Gram-negative rod known to cause invasive infection in very low birth weight infants but is an unusual pathogen to cause outbreaks in neonatal intensive care units (NICU).

METHODS

We performed a retrospective analysis of all patients colonized with K. aerogenes in our NICU from September to December 2018. Each infant with an occurrence of K. aerogenes in any microbiological culture was defined as a case. Clinical data were taken from medical charts. K. aerogenes isolates were genotyped using whole-genome sequencing combined with core genome multilocus sequencing type analysis. Yersiniabactin production was evaluated by luciferase assay.

RESULTS

In total 16 patients were colonized with K. aerogenes over the 3-month period and 13 patients remained asymptomatic or developed late-onset neonatal sepsis from another pathogen. Three patients developed necrotizing enterocolitis, 2 complicated by sepsis and 1 of them died. All symptomatic patients were premature infants with low birth weight. Genetic sequencing confirmed an outbreak with the same strain, all samples expressed the high-pathogenicity island, necessary for the production of yersiniabactin. Six exemplary cases were proven to produce yersiniabactin in vitro.

CONCLUSION

This is the first report of an outbreak of a yersiniabactin-producing K. aerogenes strain causing invasive infection in preterm infants. We hypothesize that, due to improved iron uptake, this strain was associated with higher virulence than non-yersiniabactin-producing strains. Extended search for virulence factors and genetic sequencing could be pivotal in the management of NICU outbreaks in the future.

Preventable contributors to the neonatal healthcare-associated infections: a uni-center analytical study from South India

Background: Globally, neonatal healthcare-associated infections (HAIs) are known to cause high mortality. HAIs is a preventable condition related to the healthcare environment. The current study explored the contributors to neonatal HAIs in one of the largest tertiary care referral hospitals in South India.

Methods: Neonates from December 2016 to June 2018 were observed for the occurrence of healthcare-associated infections and compared with the matched control group. Various observations on neonatal demography, maternal contributors, and medical procedures were made and recorded to explore and analyse the contributors to neonatal HAIs. Univariate and multivariate analysis was carried out to find the contributors. The Odds ratio with 95% CI was also computed and reported.

Results: Bloodstream infection (83%) was prevalent among neonates; the maternal contributor was only preterm labor (Odds ratio of 11.93; 95% CI; 6.47-21.98; p<.05) to acquire HAIs. On univariate analysis, mechanical ventilation for > 3days duration, NIV for > five days, and PICC line insertion procedure were significant (p<0.05) contributors to neonatal HAIs. IV cannulation for more than three times in four consecutive days was found in 100(85%) neonates considered being associated with neonatal HAIs. On multivariate analysis, NIV, PICC line, preterm labor, and low birth weight were significant (p<0.05) contributors to neonatal HAIs.

Conclusion: The increased duration of invasive and non-invasive therapeutic devices and catheters contributes to neonatal HAIs. Neonates are acquiring bloodstream infections; low birth weight (LBW) neonates are more susceptible to acquiring HAIs.

Sepsis treatment options identified by 10-year study of microbial isolates and antibiotic susceptibility in a level-four neonatal intensive care unit

AIM

This observational study investigated the microbiology of blood culture-positive sepsis episodes and susceptibility to empiric antibiotics in early-onset sepsis (EOS) and late-onset sepsis (LOS) in a level-four neonatal intensive care unit (NICU) from 2010 to 2019.

METHODS

It was based on patient records and data that Oslo University Hospital, Norway, routinely submitted to the Norwegian Neonatal Network database. Clinical data were merged with blood culture results, including antibiotic susceptibility.

RESULTS

We studied 5249 infants admitted to the NICU 6321 times and identified 324 positive blood cultures from 287 infants, with 30 EOS and 305 LOS episodes. Frequent causative agents for EOS were group B streptococci (33.3%), Escherichia coli (20.0%) and Staphylococcus aureus (16.7%). All were susceptible to empiric ampicillin and gentamicin. LOS was most frequently caused by coagulase-negative staphylococci (CONS) (73.8%), Staphylococcus aureus (15.7%) and Enterococci (6.9%). CONS, Staphylococcus aureus, Enterococci, Escherichia coli, Klebsiella and Enterobacter represented 91.9% of LOS episodes and were susceptible to vancomycin and cefotaxime (96.1%), vancomycin and gentamicin (97.0%) and cloxacillin and gentamicin (38.1%).

CONCLUSION

Empiric treatment with ampicillin and gentamicin was adequate for EOS. Combining vancomycin and gentamicin may be a safer alternative to cefotaxime for LOS, as this reduces exposure to broad-spectrum antibiotics.

Neonatal Feeding Tube Colonization and the Potential Effect on Infant Health: A Review

Background

Infants in the neonatal intensive care unit (NICU) often require feeding tubes (FT) for weeks to months. Because FTs are in near constant contact with human milk and/or formula, rapid and extensive bacterial growth is possible. Due to their immature immunologic and gastrointestinal (GI) systems, infants may be at significant health risk due to FT colonization. In adults, length of time FTs remain in place (dwell time) affects the degree of colonization and biofilm formation which is important in infants whose tubes remain in place up to 30 days.

Objective

The purpose of this review was to describe and summarize the evidence regarding FT bacterial colonization in infants and identify gaps needing further investigation.

Methods

Medline, CINAHL, and Embase databases were searched for clinical and/or laboratory-based observational and randomized controlled studies investigating the presence of bacteria in neonatal FTs.

Results

This review of 10 studies found evidence that neonatal FTs may contain high quantities of potentially pathogenic and antibiotic resistant bacteria and longer dwell times may increase the bacterial load. Furthermore, evidence suggests FT colonization may be nosocomial in origin and contribute to adverse infant health. Feeding tubes are an unrecognized source of bacterial colonization which may increase morbidity in premature infants and thus the presence of bacteria in FTs is an important area of investigation in the nutritional care of vulnerable infants in the NICU.

Implications

Further appropriately powered studies which are clinically based, use appropriate analyses, and control for potential covariates are necessary to make clinical recommendations.

Morbidity and mortality in small for gestational age very preterm infants in a middle-income country

OBJECTIVE

To evaluate the impact of small for gestational age (SGA) on outcomes of very preterm infants at Groote Schuur Hospital (GSH), Cape Town, South Africa.

STUDY DESIGN

Data were obtained from the Vermont Oxford Network (VON) GSH database from 2012 to 2018. The study is a secondary analysis of prospectively collected observational data. Fenton growth charts were used to define SGA as birth weight < 10th centile for gestational age.

RESULTS

Mortality [28.9% vs. 18.5%, adjusted risk ratio (aRR) 2.1, 95% confidence interval (CI) 1.6-2.7], bronchopulmonary dysplasia (BPD; 14% vs. 4.5%, aRR 3.7, 95% CI 2.3-6.1), and late-onset sepsis (LOS; 16.7% vs. 9.6%, aRR 2.3, 95% CI 1.6-3.3) were higher in the SGA than in the non-SGA group.

CONCLUSION

Small for gestational age infants have a higher risk of mortality and morbidity among very preterm infants at GSH. This may be useful for counseling and perinatal management.

Hyperoxia/Hypoxia Exposure Primes a Sustained Pro-Inflammatory Profile of Preterm Infant Macrophages Upon LPS Stimulation

Preterm infants are highly susceptible to sustained lung inflammation, which may be triggered by exposure to multiple environmental cues such as supplemental oxygen (O₂) and infections. We hypothesized that dysregulated macrophage (MФ) activation is a key feature leading to inflammation-mediated development of bronchopulmonary dysplasia (BPD) in preterm infants. Therefore, we aimed to determine age-dependent differences in immune responses of monocyte-derived MФ comparing cord blood samples derived from preterm (n=14) and term (n=19) infants as well as peripheral blood samples from healthy adults (n=17) after lipopolysaccharide (LPS) exposure. Compared to term and adult MФ, LPS-stimulated preterm MФ showed an enhanced and sustained pro-inflammatory immune response determined by transcriptome analysis, cytokine release inducing a RORC upregulation due to T cell polarization of neonatal T cells, and TLR4 surface expression. In addition, a double-hit model was developed to study pulmonary relevant exposure factors by priming MФ with hyperoxia (O₂ = 65%) or hypoxia (O₂ = 3%) followed by lipopolysaccharide (LPS, 100ng/ml). When primed by 65% O₂, subsequent LPS stimulation in preterm MФ led to an exaggerated pro-inflammatory response (e.g. increased HLA-DR expression and cytokine release) compared to LPS stimulation alone. Both, exposure to 65% or 3% O₂ together with subsequent LPS stimulation, resulted in an exaggerated pro-inflammatory response of preterm MФ determined by transcriptome analysis. Downregulation of two major transcriptional factors, early growth response gene (Egr)-2 and growth factor independence 1 (Gfi1), were identified to play a role in the exaggerated pro-inflammatory response of preterm MФ to LPS insult after priming with 65% or 3% O₂. Preterm MФ responses to LPS and hyperoxia/hypoxia suggest their involvement in excessive inflammation due to age-dependent differences, potentially mediated by downregulation of Egr2 and Gfi1 in the developing lung.

Gut priming with bovine colostrum and T regulatory cells in preterm neonates: a randomized controlled trial

BACKGROUND

Necrotizing enterocolitis (NEC) and neonatal sepsis are still considered major problems, especially in formula-fed preterm neonates. This study aimed to investigate the effect of bovine colostrum on T regulatory cells, NEC, and late-onset sepsis in preterm neonates ≤34 weeks.

METHODS

This prospective double-blind randomized controlled trial was conducted on 80 preterm infants who were randomly assigned to either the bovine colostrum group (n = 32) or control group (n = 48). T lymphocytes and their subsets, necrotizing enterocolitis, late-onset sepsis (LOS) and its severity, feeding tolerance, growth, length of hospital stay, and mortality were documented.

RESULTS

The bovine colostrum group showed higher follow-up levels of CD4+CD25+ FOXP3+ T lymphocyte % (FOXP3 Tregs). FOXP3 Tregs and its difference in change levels between baseline and follow-up were considered as the most related factors to the bovine colostrum. Bovine colostrum group showed positive trends for reduction of sepsis severity and mortality with no significant difference in the incidence of NEC, LOS, and length of hospital stay.

CONCLUSIONS

Preterm neonates who received bovine colostrum showed a higher FOXP3 Treg level.

IMPACT

Bovine colostrum has no significant effect on the incidence of necrotizing enterocolitis. FOXP3 T regulatory cells and their increased level between baseline and follow-up is considered as the most influencing factors related to the bovine colostrum. Positive trends were noted for reduction of sepsis severity and concomitant mortality, but the study lacked the power to assess these outcomes.

The road to zero nosocomial infections in neonates-a narrative review

Aim

Nosocomial infections (NI) in neonates are associated with prolonged hospitalisation, adverse neurodevelopmental outcome and high mortality. Over the past decade, numerous prevention strategies have resulted in significant reductions in NI rates. In this review, we aim to provide an overview of current NI rates from large, geographically defined cohorts.

Methods

PubMed, Web of Science, EMBASE and Cochrane Library were searched for evidence regarding epidemiology and prevention of NI in neonates. Extracted studies were synthesised in a narrative form with experiential reflection.

Results

Despite the abundance of geographically defined incidence proportions, an epidemiological overview of NI is difficult to provide, given the lack of consensus definition for neonatal NI and different baseline populations being compared. Successful prevention efforts have focused on implementing evidence‐based practices while eliminating outdated strategies. The most promising model for reduction in infection rates is based on quality improvement (QI) collaboratives and benchmarking, involving identification and implementation of best practices, selection of measurable outcomes and fostering a sense of community and transparency.

Conclusion

The preventative rather than curative approach forms the new paradigm for reducing the burden of neonatal infections. Despite progress achieved, continued work towards improved prevention practices is required in the strive towards zero NIs.

[A clinical analysis of sepsis in very low birth weight infants]

OBJECTIVE

To study the incidence and clinical features of sepsis in very low birth weight (VLBW) infants.

METHODS

The clinical data were collected from VLBW infants, with a birth weight of < 1 500 g, who were admitted to the Department of Neonatology, Maternity Hospital Affiliated to Nanjing Medical University, from January 2019 to June 2020. The incidence of sepsis, distribution of pathogenic bacteria, and risk factors for sepsis were analyzed.

RESULTS

A total of 369 infants were enrolled, and 138 infants had sepsis, among whom 84 had early-onset sepsis (EOS) and 54 had late-onset sepsis (LOS). Enterococcus faecalis (24%) and Streptococcus (21%) were the main pathogenic bacteria in infants with EOS, and Staphylococcus (41%) and Enterobacter (29%) were the main pathogenic bacteria in infants with LOS. The incidence of EOS and LOS decreased with the increase of gestational age and birth weight (P < 0.05). The multivariate logistic regression analysis showed that a high birth weight was a protective factor against EOS (OR=0.996, 95%CI:0.993-0.998, P < 0.05), while vaginal delivery (OR=2.781, 95%CI:1.190-6.500, P < 0.05) was a risk factor for EOS, and long duration of parenteral nutrition was a risk factor for LOS (OR=1.129, 95%CI:1.067-1.194, P < 0.05).

CONCLUSIONS

Enterococcus faecalis is the most common pathogenic bacteria for EOS, and Staphylococcus is the most common pathogenic bacterium for LOS in VLBW infants. A high birth weight may reduce the risk of EOS in VLBW infants, while vaginal delivery may increase the risk of EOS. Prolonged parenteral nutrition may increase the risk of LOS.

Antibiotic regimens for late-onset neonatal sepsis

BACKGROUND

Neonatal sepsis is a major cause of morbidity and mortality. It is the third leading cause of neonatal mortality globally constituting 13% of overall neonatal mortality. Despite the high burden of neonatal sepsis, high-quality evidence in diagnosis and treatment is scarce. Due to the diagnostic challenges of sepsis and the relative immunosuppression of the newborn, many neonates receive antibiotics for suspected sepsis. Antibiotics have become the most used therapeutics in neonatal intensive care units, and observational studies in high-income countries suggest that 83% to 94% of newborns treated with antibiotics for suspected sepsis have negative blood cultures. The last Cochrane Review was updated in 2005. There is a need for an updated systematic review assessing the effects of different antibiotic regimens for late-onset neonatal sepsis.

OBJECTIVES

To assess the beneficial and harmful effects of different antibiotic regimens for late-onset neonatal sepsis.

SEARCH METHODS

We searched the following electronic databases: CENTRAL (2021, Issue 3); Ovid MEDLINE; Embase Ovid; CINAHL; LILACS; Science Citation Index EXPANDED and Conference Proceedings Citation Index - Science on 12 March 2021. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

We included RCTs comparing different antibiotic regimens for late-onset neonatal sepsis. We included participants older than 72 hours of life at randomisation, suspected or diagnosed with neonatal sepsis, meningitis, osteomyelitis, endocarditis, or necrotising enterocolitis. We excluded trials that assessed treatment of fungal infections.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed studies for inclusion, extracted data, and assessed risk of bias. We used the GRADE approach to assess the certainty of evidence. Our primary outcome was all-cause mortality, and our secondary outcomes were: serious adverse events, respiratory support, circulatory support, nephrotoxicity, neurological developmental impairment, necrotising enterocolitis, and ototoxicity. Our primary time point of interest was at maximum follow-up.

MAIN RESULTS

We included five RCTs (580 participants). All trials were at high risk of bias, and had very low-certainty evidence. The five included trials assessed five different comparisons of antibiotics. We did not conduct a meta-analysis due to lack of relevant data. Of the five included trials one trial compared cefazolin plus amikacin with vancomycin plus amikacin; one trial compared ticarcillin plus clavulanic acid with flucloxacillin plus gentamicin; one trial compared cloxacillin plus amikacin with cefotaxime plus gentamicin; one trial compared meropenem with standard care (ampicillin plus gentamicin or cefotaxime plus gentamicin); and one trial compared vancomycin plus gentamicin with vancomycin plus aztreonam. None of the five comparisons found any evidence of a difference when assessing all-cause mortality, serious adverse events, circulatory support, nephrotoxicity, neurological developmental impairment, or necrotising enterocolitis; however, none of the trials were near an information size that could contribute significantly to the evidence of the comparative benefits and risks of any particular antibiotic regimen. None of the trials assessed respiratory support or ototoxicity. The benefits and harms of different antibiotic regimens remain unclear due to the lack of well-powered trials and the high risk of systematic errors.

AUTHORS' CONCLUSIONS

Current evidence is insufficient to support any antibiotic regimen being superior to another. RCTs assessing different antibiotic regimens in late-onset neonatal sepsis with low risks of bias are warranted.

Neonatal outcome of small for gestational age infants born at 26-33 weeks' gestation in Chinese neonatal intensive care units

BACKGROUND

Rate and outcomes of small for gestational age (SGA) infants admitted to Chinese neonatal intensive care units (NICU) has been poorly demonstrated. We aimed to describe the rate and outcomes of SGA preterm infants in Chinese NICU, and to evaluate the association of SGA status with neonatal outcomes in different gestational age (GA) and birth weight percentile groups.

METHODS

This cohort study included all infants born at 26-33 weeks' gestation and admitted to 25 tertiary Chinese NICUs from April 2015 to May 2018. SGA was defined as a birthweight <10th percentile for GA based on the Chinese neonatal birth weight curve.

RESULTS

A total of 24,596 infants were included, and 1,867 (7.6%) infants were SGA. SGA infants had significantly higher rates of death or any major morbidity (29.8% vs. 20.5%), mortality (7.0% vs. 4.1%), bronchopulmonary dysplasia (BPD, 17.6% vs. 9.8%), necrotizing enterocolitis (NEC, 4.8% vs. 3.2%) and sepsis (7.3% vs. 4.8%) than non-SGA infants. SGA status was independently associated with increased risk of death or any major morbidity [adjusted odds ratio: 2.37 (2.08-2.71)] as well as increased risks of death, BPD, ROP, death or BPD, death or ROP, NEC and sepsis. The increased risks of adverse outcomes for SGA infants existed across GA groups. The risks of adverse outcomes were highest among infants with a birthweight <3rd percentile.

CONCLUSIONS

SGA contributes significantly to adverse neonatal outcomes. Specific attentions are warranted when caring for SGA preterm infants.

Impaired Neonatal Immunity and Infection Resistance Following Fetal Growth Restriction in Preterm Pigs

Background: Infants born preterm or small for gestational age (SGA, due to fetal growth restriction) both show an increased risk of neonatal infection. However, it remains unclear how the co-occurrence of preterm birth and SGA may affect neonatal immunity and infection risk. We hypothesized that fetal growth restricted (FGR) preterm newborns possess impaired immune competence and increased susceptibility to systemic infection and sepsis, relative to corresponding normal birth weight (NBW) newborns.

Methods: Using preterm pigs as a model for preterm infants, gene expression in lipopolysaccharide (LPS) stimulated cord blood was compared between NBW and FGR (lowest 25% birth weight percentile) preterm pigs. Next, clinical responses to a systemic Staphylococcus epidermidis (SE) challenge were investigated in newborn FGR and NBW preterm pigs. Finally, occurrence of spontaneous infections were investigated in 9 d-old FGR and NBW preterm pigs, with or without neonatal antibiotics treatment.

Results: At birth, preterm FGR piglets showed diminished ex vivo cord blood responses to LPS for genes related to both innate and adaptive immunity, and also more severe septic responses following SE infection (e.g., higher blood lactate, decreased blood pH, neutrophil and platelet counts, relative to NBW pigs). After 9 d, FGR pigs had higher incidence and severity of spontaneous infections (e.g., higher bacterial densities in the bone marrow), increased regulatory T cell numbers, reduced neutrophil phagocytosis capacity, and impaired ex vivo blood gene responses to LPS, especially when receiving neonatal antibiotics.

Conclusion: FGR at preterm birth is associated with poor immune competence, impaired infection resistance, and greater sepsis susceptibility in the immediate postnatal period. Our results may explain the increased morbidity and mortality of SGA preterm infants and highlight the need for clinical vigilance for this highly sensitive subgroup of preterm neonates.

Challenges of Vancomycin Dosing and Therapeutic Monitoring in Neonates

Late-onset sepsis in neonates can lead to significant morbidity and mortality, especially in preterm infants. Vancomycin is commonly prescribed for the treatment of Gram-positive organisms, particularly methicillin-resistant Staphylococcus aureus (MRSA), coagulase-negative staphylococci, and ampicillin-resistant Enterococcus species in adult and pediatric patients. Currently, there is no consensus on optimal dosing and monitoring of vancomycin in neonates. Different vancomycin dosing regimens exist for neonates, but with many of these regimens, obtaining therapeutic trough concentrations can be difficult. In 2011, the Infectious Diseases Society of America recommended vancomycin trough concentrations of 15 to 20 mg/L or an AUC/MIC ratio of ≥400 for severe invasive diseases (e.g., MRSA) in adult and pediatric patients. Owing to recent reports of increased risk of nephrotoxicity associated with vancomycin trough concentrations of 15 to 20 mg/L and AUC/MIC of ≥400, a revised consensus guideline, recently published in 2020, no longer recommends monitoring vancomycin trough concentrations in adult patients. The guideline recommends an AUC/MIC of 400 to 600, which has been found to achieve clinical efficacy while reducing nephrotoxicity. However, these recommendations were derived solely from adult literature, as there are limited clinical outcomes data in pediatric and neonatal patients. Furthermore, owing to the variation of vancomycin pharmacokinetic parameters among the neonatal population, these recommendations for achieving vancomycin AUC/MIC of 400 to 600 in neonates require further investigation. This review will discuss the challenges of achieving optimal vancomycin dosing and monitoring in neonatal patients.

Gut Dysbiosis With Bacilli Dominance and Accumulation of Fermentation Products Precedes Late-onset Sepsis in Preterm Infants

BACKGROUND

Gut dysbiosis has been suggested as a major risk factor for the development of late-onset sepsis (LOS), a main cause of mortality and morbidity in preterm infants. We aimed to assess specific signatures of the gut microbiome, including metabolic profiles, in preterm infants <34 weeks of gestation preceding LOS.

METHODS

In a single-center cohort, fecal samples from preterm infants were prospectively collected during the period of highest vulnerability for LOS (days 7, 14, and 21 of life). Following 16S rRNA gene profiling, we assessed microbial community function using microbial metabolic network modeling. Data were adjusted for gestational age and use of probiotics.

RESULTS

We studied stool samples from 71 preterm infants with LOS and 164 unaffected controls (no LOS/necrotizing enterocolitis). In most cases, the bacteria isolated in diagnostic blood culture corresponded to the genera in the gut microbiome. LOS cases had a decelerated development of microbial diversity. Before onset of disease, LOS cases had specific gut microbiome signatures with higher abundance of Bacilli (specifically coagulase-negative Staphylococci) and a lack of anaerobic bacteria. In silico modeling of bacterial community metabolism suggested accumulation of the fermentation products ethanol and formic acid in LOS cases before the onset of disease.

CONCLUSIONS

Intestinal dysbiosis preceding LOS is characterized by an accumulation of Bacilli and their fermentation products and a paucity of anaerobic bacteria. Early microbiome and metabolic patterns may become a valuable biomarker to guide individualized prevention strategies of LOS in highly vulnerable populations.

Diet Modulates the High Sensitivity to Systemic Infection in Newborn Preterm Pigs

Background: Preterm infants are born with an immature immune system, limited passive immunity, and are at risk of developing bacteremia and sepsis in the postnatal period. We hypothesized that enteral feeding, with or without added immunoglobulins, improves the clinical response to systemic infection by coagulase negative staphylococci.

Methods: Using preterm cesarean delivered pigs as models for preterm infants, we infused live Staphylococcus epidermidis (SE, 5 × 10⁹ colony forming units per kg) systemically 0–3 days after birth across five different experiments. SE infection responses were assessed following different gestational age at birth (preterm vs. term), enteral milk diets (bovine colostrum, infant formula with or without added porcine plasma) and with/without systemic immunoglobulins. Pigs infected with SE were assessed 12–48 h for clinical variables, blood bacteriology, chemistry, hematology, and gut dysfunction (intestinal permeability, necrotizing enterocolitis lesions).

Results: Adverse clinical responses and increased mortality were observed in preterm vs. term pigs, when infected with SE just after birth. Feeding bovine colostrum just after birth improved blood SE clearance and clinical status (improved physical activity and intestinal structure, fewer bone marrow bacteria), relative to pigs fed infant formula. A few days later, clinical responses to SE bacteremia (hematology, neutrophil phagocytic capacity, T cell subsets) were less severe, and less affected by different milk diets, with or without added immunoglobulins.

Conclusion: Prematurity increases the sensitivity of newborn pigs to SE bacteremia, potentially causing sepsis. Sensitivity to systemic SE infection decreases rapidly in the days after preterm birth. Both age and diet (parenteral nutrition, colostrum, milk, formula) may influence gut inflammation, bacterial translocation and systemic immune development in the days after birth in preterm newborns.

Late-onset sepsis and mortality among neonates in a Brazilian Intensive Care Unit: a cohort study and survival analysis

A cohort study was performed from January 2014 to December 2016 in a Brazilian neonatal intensive care unit, including neonates with high risk for infection and death. We estimated bloodstream infection (BSI) incidence and conducted a survival analysis, considering the time to death and to the first episode of BSI as outcomes, comparing very low birth weight (VLBW) neonates with the remaining neonates. An extended Cox model was performed and the hazard ratio (HR) was calculated for different time periods. The study had 1560 neonates included, the incidence and the incidence density of BSI was 22% and 18.6 per 1000 central venous catheter-days, respectively. Considering VLBW neonates as the reference group, the HR for time to death was 4.06 (95% CI 2.75–6.00, P < 0.01) from day 0 to 60 and for time to the first episode of BSI was 1.76 (95% CI 1.31–2.36, P < 0.01) from day 0 to 36. Having the heavier neonates group as reference, the HR for time to the first episode of BSI was 2.94 (95% CI 1.92–4.34, P < 0.01) from day 37 to 90. Late-onset neonatal sepsis prevention measures should consider the differences in risk during time, according to neonates' birth weight.

Colonization Screening Targeting Multidrug-Resistant Gram-Negative Pathogens Does Not Increase the Use of Carbapenems in Very Low Birth Weight Infants

Since 2012, a colonization screening (CoS) for multidrug-resistant Gram-negative bacteria (MRGN) in very low birth weight infants (VLWBI) was implemented in order to provide a basis for an effective empiric therapy of subsequent nosocomial infections (NI). According to antibiotic stewardship, carbapenems should be reserved for NI caused by MRGN or severe NI. We examined whether the CoS increased the first-line use of carbapenems. In this retrospective cohort analysis, we enrolled all VLBWI before (2009-2011) and after (2012-2014) the introduction of CoS (2012) at a tertiary university neonatal intensive care and neonatal intermediate care unit (NIMC) in Germany. Rectal swabs were used to detect MRGN colonization (on admission and weekly until discharge from the NIMC). The use of carbapenems was measured by days of therapy (DoT). To exclude the replacement of carbapenems by other antibiotics, antibiotic therapy for late-onset sepsis (LOS) was assessed by DoT and length of therapy (LoT). In 55/201 (27.4%) VLBWI, CoS detected MRGN colonization. Compared to the cohort prior to the introduction of CoS (n = 191), a significant decrease in LoT (p < 0.001) and total DoT (p < 0.001) was seen (n = 201). This was due to a significant decrease in LoT (p < 0.001) and total DoT (p < 0.001) in the birth weight category of 1,000-1,499 g. In these infants, DoT for carbapenems (p = 0.009) was significantly lower, possibly caused by a significant decline of LOS (25 episodes vs. 39 episodes, p = 0.025). Conversely, no significant differences in LoT and total DoT were seen in infants with a birth weight <500 g (p = 1.000; p = 0.758) and in infants weighing 500-999 g (p = 0.754; p = 0.794). DoT for carbapenems was not significantly different in the total cohort after the introduction of CoS (p = 0.341). Prolonged exposure to carbapenems (in terms of DoT) significantly postponed the first detection of MRGN colonization (p = 0.023). The introduction of CoS did not result in an increased use of carbapenems. Concomitant carbapenem treatment may reduce the sensitivity of CoS relying on rectal swabs.

An exclusive human milk diet for very low birth weight newborns-A cost-effectiveness and EVPI study for Germany

OBJECTIVES

Human milk-based fortifiers have shown a protective effect on major complications for very low birth weight newborns. The current study aimed to estimate the cost-effectiveness of an exclusive human milk diet (EHMD) compared to the current approach using cow's milk-based fortifiers in very low birth weight newborns.

METHODS

A decision tree model using the health states of necrotising enterocolitis (NEC), sepsis, NEC + sepsis and no complication was used to calculate the cost-effectiveness of an EHMD. For each health state, bronchopulmonary dysplasia (BPD), retinopathy of prematurity (RoP) and neurodevelopmental problems were included as possible complications; additionally, short-bowel syndrome (SBS) was included as a complication for surgical treatment of NEC. The model was stratified into birth weight categories. Costs for inpatient treatment and long-term consequences were considered from a third party payer perspective for the reference year 2017. Deterministic and probabilistic sensitivity analyses were performed, including a societal perspective, discounting rate and all input parameter-values.

RESULTS

In the base case, the EHMD was estimated to be cost-effective compared to the current nutrition for very low birth weight newborns with an incremental cost-effectiveness ratio (ICER) of €28,325 per Life-Year-Gained (LYG). From a societal perspective, the ICER is €27,494/LYG using a friction cost approach and €16,112/LYG using a human capital approach. Deterministic sensitivity analyses demonstrated that the estimate was robust against changes in the input parameters and probabilistic sensitivity analysis suggested that the probability EHMD was cost-effective at a threshold of €45,790/LYG was 94.8 percent.

CONCLUSION

Adopting EHMD as the standard approach to nutrition is a cost-effective intervention for very low birth weight newborns in Germany.

Antibiotic regimens for neonatal sepsis - a protocol for a systematic review with meta-analysis

BACKGROUND

Sepsis is a major cause of morbidity and mortality among neonates and infants. Antibiotics are a central part of the first line treatment for sepsis in neonatal intensive care units worldwide. However, the evidence on the clinical effects of the commonly used antibiotic regimens for sepsis in neonates remains scarce. This systematic review aims to assess the efficacy and harms of antibiotic regimens for neonatal sepsis.

METHODS

Electronic searches will be conducted in MEDLINE, Embase, The Cochrane Library, CINAHL, ZETOC and clinical trial registries (clinicaltrials.gov and ISRCTN). We will include randomised controlled trials of different antibiotic regimens for sepsis of neonates and infants. Eligible interventions will be any antibiotic regimen. Two reviewers will independently screen, select, and extract data. The methodological quality of individual studies will be appraised following Cochrane methodology. Primary outcomes will be 'all-cause mortality' and 'serious adverse events'. Secondary outcomes will be 'need for respiratory support', 'need for circulatory support', 'neurodevelopmental impairment', ototoxicity, nephrotoxicity and necrotizing enterocolitis. We plan to perform a meta-analysis with trial sequential analysis.

DISCUSSION

This is the study protocol for a systematic review on the effects of different antibiotic regimens for neonatal sepsis. The results of this systematic review intent to adequately inform stakeholders or health care professionals in the field of neonatal sepsis, and to aid appropriate development of treatment guidelines.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO reference number: CRD42019134300.

Growth Restriction and Systemic Immune Development in Preterm Piglets

Background: Many preterm infants are born with growth restriction (GR) following maternal or fetal complications before birth. Such infants may continue to grow slowly after birth, regardless of birth weight (BW), due to morbidities related to their immature organs. Severe GR increases the susceptibility to infections, but it is not clear if this is a consequence of impaired systemic immunity or other factors, such as prolonged hospital stay or poor mucosal barrier function. Using preterm pigs as models for preterm infants, we hypothesized that moderate GR, exerting limited clinical effects, does not influence systemic immune development.

Methods: Preterm pigs were delivered by cesarean section and fed bovine milk diets until 19 d. Piglets with fetal growth restriction (F-GR, the lowest 25% of BW, n = 27, excluding those with BW <350 g) and postnatal growth restriction (P-GR, the lowest 25% of postnatal growth rate, n = 24) were compared with their corresponding controls (F-CON, n = 92, and P-CON, n = 85, respectively). Organ weights were determined and blood collected for assessment of clinical status (blood chemistry and hematology). For a subgroup (n = 58), in depth analyses of neutrophil function, T cell counts, plasma cytokine levels, and leucocyte gene expression were performed.

Results: For F-GR pigs, adrenal gland weight was increased and bone mineral content decreased at 19 d. Total leucocyte levels were lower at birth and interleukin-10 levels increased at d 8–10. In P-GR pigs, total leucocyte, neutrophil, monocyte, and eosinophil counts along with helper T cell fractions were elevated at 8–19 d of age, while the fraction of neutrophils with phagocytic capacity was reduced. Diarrhea and all remaining organ weights, blood chemistry, and immune variables were not affected by F-GR or P-GR.

Conclusion: Moderate GR before and after preterm birth has limited effect on systemic immune development in preterm pigs, despite marginal effects on immune cell populations, adrenocortical function, and body composition. Similar responses may be observed for preterm infants with moderate fetal and postnatal growth restriction.

A survey of the implementation status of selected infection control strategies in neonatal intensive care units in Japan

BACKGROUND

Infection control strategies are implemented in all neonatal intensive care units (NICUs); however, the details of the strategies seem to differ among institutions. The purpose of this survey was to investigate the current implementation status of infection control strategies in NICUs in Japan and to identify and recommend appropriate strategies for the prevention of outbreaks in neonatal units.

METHODS

This survey documented the current implementation status and methods of selected infection prevention and control measures (active surveillance cultures and standard precaution) in 453 Japanese NICUs/neonatal units registered with the Japan Society of Perinatal and Neonatal Medicine, using questionnaires, in May 2018.

FINDINGS

The response rate was 48.1% (level I institutions, 25.5%; level II, 55.9%; level III, 64.2%). Surveillance cultures were performed every week and targeted all bacteria in most units. The proportion of level III institutions that experienced outbreaks over the previous five years was significantly higher than that of level II institutions (55% vs 27%, P=0.0003). However, wearing a mask was less frequently recommended in level III institutions (55.7%) than in level II institutions (67.9%). Meticillin-resistant Staphylococcus aureus (MRSA) was the most frequently reported bacterial pathogen responsible for NICU outbreaks.

CONCLUSION

Infection prevention and control practices regarding active pathogen surveillance cultures and the use of barrier precautions varied widely in Japanese neonatal units. National guidelines and evidence-based recommendations are needed to rationalize and standardize current infection prevention and control practices in neonatal units in Japan.

[A clinical analysis of late-onset sepsis in very low birth weight and extremely low birth weight infants]

OBJECTIVE

To study the clinical features and pathogenic bacteria of late-onset sepsis (LOS) in very low birth weight (VLBW) and extremely low birth weight (ELBW) infants.

METHODS

Among the VLBW/ELBW infants with a gestational age of <32 weeks who were admitted to the hospital between January 2012 and December 2016, those with LOS were enrolled as the LOS group, and those without sepsis were matched for the infant with LOS in gestational age were enrolled as the control group. According to the presence or absence of in-hospital death, the LOS group was further divided into a death subgroup and a survival subgroup. Risk factors for LOS, clinical features, distribution of pathogenic bacteria, drug resistance, and high-risk factors for LOS-related death were analyzed.

RESULTS

A total of 513 VLBW/ELBW infants were enrolled, and there were 65 infants in the LOS group and 130 in the control group. The incidence rate of LOS was 12.7%. In the LOS group, 6 infants died and 59 survived. Compared with the control group, the LOS group had a significantly lower birth weight (P<0.05) and significantly longer indwelling time of peripherally inserted central catheter (PICC), duration of mechanical ventilation, and length of hospital stay (P<0.05). Compared with the control group, the LOS group had a significantly higher proportion of small-for-gestational-age infants, infants undergoing mechanical ventilation, infants with neonatal necrotizing enterocolitis, or infants who died (P<0.05). Low birth weight, small-for-gestational-age infant, and long indwelling time of PICC were independent risk factors for LOS in VLBW/ELBW infants (OR=1.396, 2.550, and 1.068 respectively, P<0.05). Purulent meningitis was an independent risk factor for LOS-related death in VLBW/ELBWIs infants (OR=13.443, P<0.05). A total of 65 strains of pathogenic bacteria were cultured in the LOS group, among which there were 39 strains (60%) of Gram-negative bacteria, including 15 strains producing extended spectrum beta-lactamases (ESBLs), and antibiotics were applied for 67% (10/15) of the ESBL strains within 2 weeks before the onset of LOS. The rate of antibiotic use for ESBL strains was significantly higher than that for non-resistant strains [67% (10/15) vs 29% (7/24); P<0.05].

CONCLUSIONS

Low birth weight, SGA infant, and long indwelling time of PICC are independent risk factors for LOS in VLBW/ELBW infants, and death tends to occur in LOS infants with purulent meningitis. Most pathogenic bacteria of LOS are Gram-negative bacteria, and use of antibiotics within 2 weeks before disease onset may increase the risk of ESBL strain infection.

Clinical outcome and isolated pathogens among neonates with sepsis in Democratic Republic of the Congo: a cross-sectional study

Objective

Neonatal sepsis still remains a significant cause of morbidity and mortality in developing countries. The prediction of the neonatal sepsis outcome depends on the anticipation from the clinical history, suspicion from clinical findings and confirmation by laboratory tests. This study aimed to determine the clinical outcome and isolated pathogens among neonates with sepsis in Butembo, Democratic Republic of the Congo.

Results

The most frequent bacteria related to a poor outcome were Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella spp. Most of isolated bacteria were found to be hospital-acquired infections. Therefore, adherence to infection prevention and control measures would reduce reduced rate of neonatal sepsis in our setting. The empiric antibiotic treatment should cover the spectrum of bacteria responsible of neonatal sepsis in Butembo, DRC.

Electronic supplementary material

The online version of this article (10.1186/s13104-019-4346-5) contains supplementary material, which is available to authorized users.

Rational Use of Antibiotics in Neonates: Still in Search of Tailored Tools

Rational medicine use in neonates implies the prescription and administration of age-appropriate drug formulations, selecting the most efficacious and safe dose, all based on accurate information on the drug and its indications in neonates. This review illustrates that important uncertainties still exist concerning the different aspects (when, what, how) of rational antibiotic use in neonates. Decisions when to prescribe antibiotics are still not based on robust decision tools. Choices (what) on empiric antibiotic regimens should depend on the anticipated pathogens, and the available information on the efficacy and safety of these drugs. Major progress has been made on how (beta-lactam antibiotics, aminoglycosides, vancomycin, route and duration) to dose. Progress to improve rational antibiotic use necessitates further understanding of neonatal pharmacology (short- and long-term safety, pharmacokinetics, duration and route) and the use of tailored tools and smarter practices (biomarkers, screening for colonization, and advanced therapeutic drug monitoring techniques). Implementation strategies should not only facilitate access to knowledge and guidelines, but should also consider the most effective strategies (‘skills’) and psychosocial aspects involved in the prescription process: we should be aware that both the decision not to prescribe as well as the decision to prescribe antibiotics is associated with risks and benefits.

Late-onset sepsis caused by Gram-negative bacteria in very low birth weight infants: a systematic review

INTRODUCTION

Very low birth weight (VLBW) infants are highly susceptible to late-onset sepsis (LOS). Compared to Gram-positive bacteria, Gram-negative bacteria are less common to cause LOS, but are associated with a more severe clinical manifestation, higher mortality, and increased risk of neonatal morbidity. So far, the clinical picture of late-onset Gram-negative sepsis (LOGNS) in VLBW infants has not been elucidated. An up-to-date and thorough understanding of the clinical picture of LOGNS in VLBW infants is important to optimize current anti-sepsis protocols. Areas covered: Literature published in the last three decades was searched for data on the epidemiology, pathogen profile, risk factors, clinical manifestations, laboratory parameters, mortality, and short-term and long-term morbidity of LOGNS in VLBW infants. Expert opinion: Gram-negative bacteria are major contributors of neonatal morbidity and mortality in VLBW infants with LOS, potentially posing a significant disease burden. Unravelling the pathogen-specific clinical picture of LOGNS and the underlying mechanisms is of particular interest. VLBW infants may differ from more mature neonates in terms of disease burden and clinical course of LOGNS. Epidemiologic studies aided by advanced molecular techniques may help to develop anti-sepsis protocols specialized for VLBW infants, with strategies targeting Gram-negative bacteria.

Risk Factors for Late-Onset Sepsis in Preterm Infants: A Multicenter Case-Control Study

BACKGROUND

Late-onset sepsis (LOS) in preterm infants is a leading cause of mortality and morbidity. Timely recognition and initiation of antibiotics are important factors for improved outcomes. Identification of risk factors could allow selection of infants at an increased risk for LOS.

OBJECTIVES

The aim was to identify risk factors for LOS.

METHODS

In this multicenter case-control study, preterm infants born at ≤30 weeks of gestation were included at 9 neonatal intensive care units. Detailed demographical and clinical data were collected daily up to day 28 postnatally. Clinical and demographic risk factors were identified using univariate and multivariate regression analyses in a 1: 1 matched case-control cohort.

RESULTS

In total, 755 infants were included, including 194 LOS cases (41 gram-negative cases, 152 gram-positive cases, and 1 fungus). In the case-control cohort, every additional day of parenteral feeding increased the risk for LOS (adjusted OR = 1.29; 95% CI 1.07-1.55; p = 0.006), whereas antibiotics administration decreased this risk (OR = 0.08; 95% CI 0.01-0.88; p = 0.039). These findings could largely be attributed to specific LOS-causative pathogens, since these predictive factors could be identified for gram-positive, but not for gram-negative, LOS cases. Specifically cephalosporins administration prior to clinical onset was inversely related to coagulase-negative staphylococcus LOS (CoNS-LOS) development. Formula feeding was an independent risk factor for development of CoNS-LOS (OR = 3.779; 95% CI 1.257-11.363; p = 0.018).

CONCLUSION

The length of parenteral feeding was associated with LOS, whereas breastmilk administration was protective against CoNS-LOS. A rapid advancement of enteral feeding, preferably with breastmilk, may proportionally reduce the number of parenteral feeding days and consequently the risk for LOS.

Outcomes in preterm small versus appropriate for gestation infants after Bifidobacterium breve M-16 V supplementation

Introduction: Fecal bifidobacteria response after Bifidobacterium breve M-16 V supplementation was comparable in preterm small (SGA) versus appropriate for gestational age (AGA) infants.Objectives: To compare clinical outcomes between preterm SGA versus AGA infants after routine probiotic supplementation (RPS) with Bifidobacterium breve M-16V (3 × 10⁹ CFU/day).Design: Retrospective cohort study (June 2012-August 2015) comparing outcomes between preterm (<34 weeks, subgroup: <29 weeks) SGA versus AGA infants after RPS with B. breve M-16 V using multivariable regression analysis. Primary outcome: necrotizing enterocolitis (NEC)≥Stage II/all-cause mortality. Secondary outcomes: NEC ≥ Stage II, all-cause mortality, late onset sepsis (LOS), postnatal age at full feeds (PAFF).Results: Outcomes in inborn 1380/1481 (162 SGA versus 1218 AGA) admissions were analyzed. Primary outcome "NEC ≥ Stage II /all-cause mortality" was higher in SGA versus AGA infants <29 weeks (21 versus 12%; p = .040), and showed trend toward reduction (8 versus 6%; p = .057) in AGA <34 weeks. NEC ≥ Stage II, LOS, and all-cause mortality was comparable in SGA versus AGA infants <34 weeks (3 versus 2, 9 versus 8, 9% versus 6%) and <29 weeks (5 versus 4, 16 versus 9, 18% versus 19%), respectively. Median (IQR) PAFF was significantly higher in SGA versus AGA infants <34 weeks (8 (6-12) versus 7 (5-10) days), and <29 weeks (14 (12-17) versus 11 (8-16) days).Conclusions: NEC, LOS and all-cause mortality rates were similar in preterm SGA versus AGA infants after RPS with Bifidobacterium breve M-16 V, but PAFF was higher in SGA infants.

Neonatal Sepsis of Early Onset, and Hospital-Acquired and Community-Acquired Late Onset: A Prospective Population-Based Cohort Study

OBJECTIVE

To assess the epidemiology of blood culture-proven early- (EOS) and late-onset neonatal sepsis (LOS).

STUDY DESIGN

All newborn infants admitted to tertiary care neonatal intensive care units in Switzerland and presenting with blood culture-proven sepsis between September 2011 and December 2015 were included in the study. We defined EOS as infection occurring <3 days after birth, and LOS as infection ≥3 days after birth. Infants with LOS were classified as having community-acquired LOS if onset of infection was ≤48 hours after admission, and hospital-acquired LOS, if onset was >48 hours after admission. Incidence was estimated based on the number of livebirths in Switzerland and adjusted for the proportion of admissions at centers participating in the study.

RESULTS

We identified 444 episodes of blood culture-proven sepsis in 429 infants; 20% of cases were EOS, 62% hospital-acquired LOS, and 18% community-acquired LOS. The estimated national incidence of EOS, hospital-acquired LOS, and community-acquired LOS was 0.28 (95% CI 0.23-0.35), 0.86 (0.76-0.97), and 0.28 (0.23-0.34) per 1000 livebirths. Compared with EOS, hospital-acquired LOS occurred in infants of lower gestational age and was more frequently associated with comorbidities. Community-acquired LOS was more common in term infants and in male infants. Mortality was 18%, 12%, and 0% in EOS, hospital-acquired LOS, and community-acquired LOS, and was higher in preterm infants, in infants with septic shock, and in those requiring mechanical ventilation.

CONCLUSIONS

We report a high burden of sepsis in neonates with considerable mortality and morbidity. EOS, hospital-acquired LOS, and community-acquired LOS affect specific patient subgroups and have distinct clinical presentation, pathogens and outcomes.

Role of selenium supplementation in prevention of late onset sepsis among very low birth weight neonates: a systematic review of randomized controlled trials

Background: Neonatal sepsis is one of the most common causes of neonatal morbidity and mortality. Selenium has antioxidant and immune-modulating properties.Aim: The aim of this systematic review is to evaluate role of selenium supplementation in the prevention of late onset sepsis (LOS) among very low birth weight (VLBW) neonates.Methods: We searched literature for this review by searching the Cochrane Central Register of Controlled Trials (CENTRAL) electronic PubMed, Embase, and Google Scholar. We also searched for ongoing clinical trials.Results: This review included two randomized controlled trials (RCTs) that fulfilled inclusion criteria. There was statistically significant reduction in the incidence of LOS in the intervention group [23.7 versus 35.6%; relative risk (RR) 0.67; 95% CI 0.52-0.86; p= .001; number needed to treat (NNT) 8.4; 95% CI 5.2-20.96]. However, mortality due to any cause prior to hospital discharge was not statistically significant in between the groups (6.1% intervention group versus 6.9% control group; RR 0.88; 95% CI 0.49-1.61; p= .68).Conclusions: Evidences from current systematic review revealed that selenium supplementation has some role in the prevention of LOS. However, due to limited evidences and heterogeneity between studies, large RCTs are recommended among VLBW neonates.

Bacteriological profile of neonatal sepsis and antibiotic susceptibility pattern of isolates admitted at Kanti Children's Hospital, Kathmandu, Nepal

Objective

Neonatal sepsis is a major cause of morbidity and mortality of newborns (< 1 month of age). Septicemia and drug resistance is a predominant issue for neonatal death in Nepal. This study is intended to find bacteriological profile of neonatal sepsis and antibiotic susceptibility pattern of the isolates from neonates at Kanti Children’s Hospital, Kathmandu, Nepal.

Results

Out of 350 suspected cases of neonatal sepsis, 59 (16.9%) cases showed positive blood culture. The prevalent of positive blood culture with different neonatal risk factors (sex, age, birth weight, gestational age, and delivery mode) showed highest positive bacterial growth in male (52.3%); 3 or above 3 days age (71.2%); low birth weight (62.7%); preterm gestational age (31.4%); and caesarean delivery mode (63.3%). Among positive cases, the bacteriological profile was found highest for Staphylococcus aureus (35.6%) followed by Klebsiella pneumoniae (15.3%). The most sensitive and resistive antibiotics among Gram-positive isolates were gentamicin (93%) and ampicillin (78%), respectively. Meropenem and imipenem showed highest 100% effective and cefotaxime was least (28%) sensitive among Gram-negative isolates. This concludes broad ranges of bacteria are associated with neonatal sepsis and revealed variation in antibiotic susceptibility pattern among bacterial isolates.

The potential of gut microbiota and fecal volatile organic compounds analysis as early diagnostic biomarker for necrotizing enterocolitis and sepsis in preterm infants

Although the exact pathophysiological mechanisms of both necrotizing enterocolitis (NEC) and late-onset sepsis (LOS) in preterm infants are yet to be elucidated, evidence is emerging that the gut microbiota plays a key role in their pathophysiology. Areas covered: In this review, initial microbial colonization and factors influencing microbiota composition are discussed. For both NEC and LOS, an overview of studies investigating preclinical alterations in gut microbiota composition and fecal volatile organic compounds (VOCs) is provided. Fecal VOCs are considered to reflect not only gut microbiota composition, but also their metabolic activity and concurrent interaction with the host. Expert review: Heterogeneity in study protocols and applied analytical techniques hampers reliable comparison between outcomes of different microbiota studies, limiting the ability to draw firm conclusions. This dilemma is illustrated by the finding that study results often cannot be reproduced, or even contradict each other. A NEC- and sepsis specific microbial or metabolic signature has not yet been discovered. Identification of 'disease-specific' VOCs and microbiota composition may increase understanding on pathophysiological mechanisms and may allow for development of an accurate screening tool, opening avenues towards timely identification and initiation of targeted treatment for preterm infants at increased risk for NEC and sepsis.

Neonatal and Long-Term Consequences of Fetal Growth Restriction

BACKGROUND

Fetal Growth Restriction (FGR) is one of the most common noxious antenatal conditions in humans, inducing a substantial proportion of preterm delivery and leading to a significant increase in perinatal mortality, neurological handicaps and chronic diseases in adulthood. This review summarizes the current knowledge about the postnatal consequences of FGR, with a particular emphasis on the long-term consequences on respiratory, cardiovascular and neurological structures and functions.

RESULT AND CONCLUSION

FGR represents a global health challenge, and efforts are urgently needed to improve our understanding of the critical factors leading to FGR and subsequent insults to the developing organs.

Diagnostic accuracy of the ROCHE Septifast PCR system for the rapid detection of blood pathogens in neonatal sepsis-A prospective clinical trial

Introduction

Diagnosis of neonatal sepsis remains a major challenge in neonatology. Most molecular-based methods are not customized for neonatal requirements. The aim of the present study was to assess the diagnostic accuracy of a modified multiplex PCR protocol for the detection of neonatal sepsis using small blood volumes.

Methods

212 episodes of suspected neonatal late onset sepsis were analyzed prospectively using the Roche SeptiFast^® MGRADE PCR with a modified DNA extraction protocol and software-handling tool. Results were compared to blood culture, laboratory biomarkers and clinical signs of sepsis.

Results

Of 212 episodes, 85 (40.1%) were categorized as “not infected”. Among these episodes, 1 was false positive by blood culture (1.2%) and 23 were false positive by PCR (27.1%). Of 51 (24.1%) episodes diagnosed as “culture proven sepsis”, the same pathogen was detected by blood culture and PCR in 39 episodes (76.5%). In 8 episodes, more pathogens were detected by PCR compared to blood culture, and in 4 episodes the pathogen detected by blood culture was not found by PCR. One of these episodes was caused by Bacillus cereus, a pathogen not included in the PCR panel. In 76/212 (35.8%) episodes, clinical sepsis was diagnosed. Among these, PCR yielded positive results in 39.5% of episodes (30/76 episodes). For culture-positive sepsis, PCR showed a sensitivity of 90.2% (95%CI 86.2–94.2%) and a specificity of 72.9% (95%CI 67.0–79.0%).

Conclusion

The Roche SeptiFast^® MGRADE PCR using a modified DNA extraction protocol showed acceptable results for rapid detection of neonatal sepsis in addition to conventional blood culture. The benefit of rapid pathogen detection has to be balanced against the considerable risk of contamination, loss of information on antibiotic sensitivity pattern and increased costs.

Late-onset Neonatal Sepsis-A 10-year Review From North Queensland, Australia

OBJECTIVE

Late-onset sepsis (LOS) in neonates contributes significantly to both morbidity and mortality. To determine the incidence of LOS, risk factors for disease and the impact on subsequent hospital course, we evaluated a cohort of 6340 neonates admitted to the neonatal intensive care unit and of neonates (3-28 days) admitted from the community between January 2005 and January 2016.

METHODS

This was a retrospective case review of all neonates admitted with suspected LOS who had positive blood culture and/or cerebrospinal fluid cultures, for an organism determined to be a pathogen.

RESULTS

Of 6340 neonates who survived beyond 3 days, 2271 (35.8%) had 1 or more blood cultures collected for suspected LOS. Of these, 146 (6.4%) positive blood cultures were thought to represent true bacteremia. The vast majority of infections (73%) were caused by Gram-positive organisms, with coagulase-negative staphylococci accounting for 39.8% of infections. Late-onset neonatal sepsis occurred predominantly in the 24-28-week age group (75.9%) and in neonates who weighed less than 1000 g (73.6%). The incubation time for positive blood cultures for Gram-negative sepsis was less (13 hours) when compared with Gram-positive sepsis (20 hours). Thrombocytopenia, elevated C-reactive protein and chorioamnionitis were consistently associated with late-onset Gram-negative sepsis (P < 0.05). Eight neonates (6%) died secondary to LOS.

CONCLUSIONS

LOS contributes significantly to mortality and morbidity in neonates and remains a challenge to clinicians. Necessary steps to reduce late-onset neonatal sepsis should be undertaken.

Comparing very low birth weight versus very low gestation cohort methods for outcome analysis of high risk preterm infants

Background

Compared to very low gestational age (<32 weeks, VLGA) cohorts, very low birth weight (<1500 g; VLBW) cohorts are more prone to selection bias toward small-for-gestational age (SGA) infants, which may impact upon the validity of data for benchmarking purposes.

Method

Data from all VLGA or VLBW infants admitted in the 3 Networks between 2008 and 2011 were used. Two-thirds of each network cohort was randomly selected to develop prediction models for mortality and composite adverse outcome (CAO: mortality or cerebral injuries, chronic lung disease, severe retinopathy or necrotizing enterocolitis) and the remaining for internal validation. Areas under the ROC curves (AUC) of the models were compared.

Results

VLBW cohort (24,335 infants) had twice more SGA infants (20.4% vs. 9.3%) than the VLGA cohort (29,180 infants) and had a higher rate of CAO (36.5% vs. 32.6%). The two models had equal prediction power for mortality and CAO (AUC 0.83), and similarly for all other cross-cohort validations (AUC 0.81–0.85). Neither model performed well for the extremes of birth weight for gestation (<1500 g and ≥32 weeks, AUC 0.50–0.65; ≥1500 g and <32 weeks, AUC 0.60–0.62).

Conclusion

There was no difference in prediction power for adverse outcome between cohorting VLGA or VLBW despite substantial bias in SGA population. Either cohorting practises are suitable for international benchmarking.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-017-0921-x) contains supplementary material, which is available to authorized users.