How reliable is a negative blood culture result? Volume of blood submitted for culture in routine practice in a children's hospital

Lipopolysaccharide induced systemic inflammation and heart rate variability in a term newborn piglet model

BACKGROUND

Early biomarkers are needed to improve diagnosis and support antibiotic stewardship in neonatal sepsis. Heart rate variability (HRV) is proposed as such a biomarker. However, there is a lack of studies in term newborns. Infusion of lipopolysaccharide (LPS) from Escherichia coli induces systemic inflammation comparable to sepsis in newborns. We aimed to study the effect of systemic LPS induced inflammation on HRV in term newborn piglets.

METHODS

Baseline HRV was recorded for 1 h. This control period was compared to the hourly HRV for each piglet (n = 9) during 4 h of LPS infusion. For comparison, we used a mixed-effects regression model.

RESULTS

Systemic inflammation induced by LPS was found to reduce HRV. Compared to baseline, most measures of HRV decreased to lower values compared to baseline at 2 h, 3 h, and 4 h after initiation of LPS infusion. Heart rate (HR) was increased at 2 h, 3 h, and 4 h. When adjusting for HR in the mixed-effects regression model all reductions in HRV were explained by the increase in HR.

CONCLUSIONS

Reduced HRV may be an early biomarker of neonatal sepsis. However, an increase in HR alone could be an already available, more accessible, and interpretable biomarker of sepsis in term neonates.

IMPACT

In a term newborn piglet model, systemic inflammation induced by lipopolysaccharide from Escherichia coli reduced heart rate variability measures and increased heart rate. All reductions in heart rate variability were mediated by heart rate. While heart rate variability may be a biomarker of sepsis in term newborns, changes in heart rate alone could be a more readily available biomarker.

Neonatal bacterial sepsis

Neonatal sepsis remains one of the key challenges of neonatal medicine, and together with preterm birth, causes almost 50% of all deaths globally for children younger than 5 years. Compared with advances achieved for other serious neonatal and early childhood conditions globally, progress in reducing neonatal sepsis has been much slower, especially in low-resource settings that have the highest burden of neonatal sepsis morbidity and mortality. By contrast to sepsis in older patients, there is no universally accepted neonatal sepsis definition. This poses substantial challenges in clinical practice, research, and health-care management, and has direct practical implications, such as diagnostic inconsistency, heterogeneous data collection and surveillance, and inappropriate treatment, health-resource allocation, and education. As the clinical manifestation of neonatal sepsis is frequently non-specific and the current diagnostic standard blood culture has performance limitations, new improved diagnostic techniques are required to guide appropriate and warranted antimicrobial treatment. Although antimicrobial therapy and supportive care continue as principal components of neonatal sepsis therapy, refining basic neonatal care to prevent sepsis through education and quality improvement initiatives remains paramount.

Shorter versus longer duration antibiotic regimens for treatment of culture-positive neonatal sepsis

OBJECTIVES

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the safety and effectiveness of shorter versus longer duration antibiotic regimens for the treatment of culture-positive neonatal sepsis with or without meningitis.

Recovery of pathogens with implementation of a weight-based algorithm for pediatric blood cultures: an observational intervention study

BACKGROUND

Recovering pathogenic bacteria and yeast from pediatric blood cultures and reliably distinguishing between pathogens and contaminants are likely to be improved by increasing the volume of blood submitted to microbiology laboratories for culturing beyond the low volumes that have historically have been used. The primary aim of this study was to assess whether the pathogen recovery rate would increase after implementation of a weight-based algorithm for determining the intended volume of blood submitted for culturing. Secondary aims were to: 1) evaluate the effects of the algorithm implementation on the blood culture contamination rate; 2) determine whether pathogens might be found more often than contaminants in several as opposed to single bottles when more than one bottle is submitted; and 3) describe the microbiological findings for pathogens and contaminants in blood cultures by applying a clinical validation of true blood culture positivity.

METHODS

A pre-post comparison of positivity and contamination rates after increasing the theoretical blood volume and number of blood culture bottles was performed, on the basis of a clinical validation of blood culture findings as pathogens vs contaminants.

RESULTS

We examined 5327 blood cultures, including 186 with growth (123 true positives and 63 contaminated). The rate of true positive blood cultures significantly increased from 1.6% (42/2553) pre to 2.9% (81/2774, p = .002) post intervention. The rate of contaminated blood cultures did not change significantly during the study period (1.4% [35/2553] pre vs 1.0% [28/2774], p = .222) post intervention), but the proportion of contaminated cultures among all positive cultures decreased from 45% (35/77) pre to 26% (28/109, p = .005) post intervention. A microorganism that grew in a single bottle was considered a contaminant in 35% (8/23) of cases, whereas a microorganism that grew in at least two bottles was considered a contaminant in 2% (1/49, p < .001) of cases. According to common classification criteria relying primarily on the identity of the microorganism, 14% (17/123) of the recovered pathogens would otherwise have been classified as contaminants.

CONCLUSION

Implementation of a weight-based algorithm to determine the volume and number of blood cultures in pediatric patients is associated with an increase in the pathogen recovery rate.

Effect of in-line filtration in newborns: study protocol of the Intravenous Neonatal Central Access Safety (INCAS) randomized controlled trial

BACKGROUND

Particulate contamination due to infusion therapy (administration of parenteral nutrition and medications) carries a potential health risk for infants in neonatal intensive care units (NICUs). This particulate consists of metals, drug crystals, glass fragments, or cotton fibers and can be generated by drug packaging, incomplete reconstitution, and chemical incompatibilities. In-line filters have been shown to remove micro-organisms, endotoxin, air, and particles in critically ill adults and older infants, but its benefits in newborn remain to be demonstrated. Moreover, 50% of inflammatory episodes in the setting of NICUs are blood culture-negative. These episodes could be partly related to the presence of particles in the infusion lines.

METHODS

A multicenter randomized single-blind controlled trial was designed. All infants admitted to NICUs for which prolonged infusion therapy is expected will be enrolled in the study and randomized to the Filter or Control arm. All patients will be monitored until discharge, and data will be analyzed according to a "full analysis set." The primary outcome is the frequency of patients with at least one sepsis-like event, defined by any association of suspected sepsis symptoms with a level of c-reactive protein (CRP) > 5 mg/L in a negative-culture contest. The frequency of sepsis, phlebitis, luminal obstruction, and the duration of mechanical ventilation and of catheter days will be evaluated as secondary outcomes. The sample size was calculated at 368 patients per arm.

DISCUSSION

This is the first multicenter randomized control trial that compares in-line filtration of parenteral nutrition and other intravenous drugs to infusion without filters. Sepsis-like events are commonly diagnosed in clinical practice and are more frequent than sepsis in a positive culture contest. The risk of these episodes in the target population is estimated at 30-35%, but this data is not confirmed in the literature. If the use of in-line filters results in a significant decrease in sepsis-like events and/or in any other complications, the use of in-line filters in all intravenous administration systems may be recommended in NICUs.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05537389, registered on 12 September 2022 ( https://classic.

CLINICALTRIALS

gov/ct2/show/results/NCT05537389?view=results ).

Pediatric blood cultures-turning up the volume: a before and after intervention study

The major determinant of blood culture (BC) diagnostic performance is blood volume, and pediatric sample volumes are frequently low. We aimed to assess BC volumes in our institution, design an intervention to increase volumes, and assess its impact. All pediatric BCs submitted over a 7-month period to the microbiology laboratory in a university hospital (including emergency department, pediatric ward, and neonatal unit) were included. A pre-intervention period assessed current practice. A multi-faceted intervention (education, guideline introduction, active feedback strategies) was collaboratively designed by all stakeholders. Impact was assessed in a post-intervention period. The main outcome measures included the percentage of samples adequately filled using three measures of sample adequacy (1) manufacturer-recommended minimum validated volume-> 0.5 ml, (2) manufacturer-recommended optimal minimum volume-> 1.0 ml, (3) newly introduced age-specific recommendations. Three hundred ninety-eight pre-intervention and 388 post-intervention samples were included. Initial volumes were low but increased significantly post-intervention (median 0.77 ml vs. 1.52 ml), with multivariable regression analysis estimating volumes increased 89% post-intervention. There were significant increases in all measures of volume adequacy, including an increase in age-appropriate filling (20.4-53.1%), with less improvement in those aged > 3 years. Overall, 68.4% of pathogens were from adequately filled cultures, while 76% of contaminants were from inadequately filled cultures. A pathogen was detected in a higher proportion of adequately filled than inadequately filled cultures (9.4% vs. 2.2%, p < 0.001).  Conclusion: Blood volume impacts BC sensitivity, with lower volumes yielding fewer pathogens and more contaminants. Focused intervention can significantly improve volumes to improve diagnostic performance. What is Known: • Blood volume is the major determinant of blood culture positivity, and yet pediatric blood culture volumes are frequently low, resulting in missed pathogens and increased contamination. What is New: • Adequately filled (for age) blood cultures have a pathogen detection rate three times higher than inadequately filled blood cultures. • This interventional study shows that collaboratively designed multi-modal interventions including focus on accurate volume measurement can lead to significant increases in blood volumes and improve blood culture diagnostic performance.

Time to Positive Blood Cultures Among Critically Ill Children Admitted to the PICU

OBJECTIVES

Our study aimed to assess the time to positivity (TTP) of clinically significant blood cultures in critically ill children admitted to the PICU.

DESIGN

Retrospective review of positive blood cultures in patients admitted or transferred to the PICU.

SETTING

Large tertiary-care medical center with over 90 PICU beds.

PATIENTS

Patients 0-20 years old with bacteremia admitted or transferred to the PICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary endpoint was the TTP, defined as time from blood culture draw to initial Gram stain result. Secondary endpoints included percentage of cultures reported by elapsed time, as well as the impact of pathogen and host immune status on TTP. Host immune status was classified as previously healthy, standard risk, or immunocompromised. Linear regression for TTP was performed to account for age, blood volume, and Gram stain. Among 164 episodes of clinically significant bacteremia, the median TTP was 13.3 hours (interquartile range, 10.7-16.8 hr). Enterobacterales, Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus pneumoniae were most commonly identified. By 12, 24, 36, and 48 hours, 37%, 89%, 95%, and 97% of positive cultures had resulted positive, respectively. Median TTP stratified by host immune status was 13.2 hours for previously healthy patients, 14.0 hours for those considered standard risk, and 10.6 hours for immunocompromised patients (p = 0.001). Median TTP was found to be independent of blood volume. No difference was seen in TTP for Gram-negative vs. Gram-positive organisms (12.2 vs. 13.9 hr; p = 0.2).

CONCLUSIONS

Among critically ill children, 95% of clinically significant blood cultures had an initial positive result within 36 hours, regardless of host immune status. Need for antimicrobial therapy should be frequently reassessed and implementation of a shorter duration of empiric antibiotics should be considered in patients with low suspicion for infection.

Epidemiology and Outcomes of Neonatal Sepsis: Experience from a Tertiary Australian NICU

INTRODUCTION

Neonatal sepsis is associated with significant mortality and morbidity. Low-middle-income countries are disproportionately affected, but late-onset sepsis (LOS) still occurs in up to 20% of infants <28 weeks in high-income countries. Understanding site-specific data is vital to guide management.

METHODS

A retrospective cohort study was conducted at King Edward Memorial Hospital (KEMH), Perth. Infants admitted between January 2012 and June 2022 were included. Data were extracted from routine electronic databases. Incidence and aetiology of sepsis were determined and the association of sepsis with neonatal outcomes analysed.

RESULTS

During the study period, 23,395 newborns were admitted with a median gestation of 37 weeks and birth weight of 2,800 g. There were 370 sepsis episodes in 350 infants; 102 were early-onset sepsis (EOS) (1.6 per 1,000 live births), predominantly Streptococcus agalactiae (35, 34.3%) and Escherichia coli (27, 26.5%); 268 were LOS (0.9 per 1,000 inpatient days), predominantly coagulase-negative staphylococci (CONS) (156, 57.6%) and E. coli (30, 11.1%). The incidence of LOS declined from 2012 to 2022 (p = 0.002). Infants with EOS had increased brain injury (25.7% vs. 4.1%; p = 0.002) and mortality (18.8% vs. 1.6%; p < 0.001). Those with LOS had increased hospital stay (median 95 vs. 15 days; p < 0.001), mortality (15.3% vs. 1.6%; p = 0.018), necrotising enterocolitis (NEC) (7.4% vs. 0.5%; p < 0.001), and chronic lung disease (CLD) (58.1% vs. 5.9%; p = 0.005). Infants <28 weeks with sepsis were at increased risk of neurodevelopmental impairment compared to those without infection (43.2% vs. 30.9%, p = 0.027).

CONCLUSIONS

While we observed a reduction in LOS incidence, sepsis remains associated with higher mortality, and in survivors with longer hospital stay and increased risk of brain injury, NEC, CLD, and neurodevelopmental impairment.

Early-onset neonatal sepsis: Effectiveness of classification based on ante- and intrapartum risk factors and clinical monitoring

INTRODUCTION

In 2017, the French public health authority HAS published new guidelines for the management of newborns at risk of early bacterial neonatal infection. These guidelines were based on ante- and intrapartum risk factors and clinical monitoring. In January 2021, we implemented a new protocol based on these guidelines in our tertiary maternity unit.

OBJECTIVES

To assess the impact of the protocol implemented on neonates' antibiotic prescriptions.

METHOD

An "old protocol" group comprising newborns hospitalized between July 1, 2020 and December 31, 2020, was compared to a "new protocol" group formed between January 14, 2021 and July 13, 2021. Data were collected on infectious risk factors, antibiotic prescriptions, and emergency room visits within 2 weeks for an infection or suspected infection.

RESULTS

The "old protocol" population comprised 1565 children and the "new protocol" population 1513. Antibiotic therapy was prescribed for 29 newborns (1.85 %) in the old protocol group versus 15 (0.99 %) in the new one (p = 0.05). The median duration was 5 days and 2 days respectively (p = 0.08). With the new protocol, newborns in category B were about 20 times more likely (p = 0.01), and those in category C about 54 times more likely (p = 0.005) to have an infection than those classified in categories N or A.

CONCLUSION

This study demonstrates that clinical monitoring criteria enable reduced use and duration of antibiotic therapy and are reliable.

Umbilical cord blood culture for early onset sepsis in preterm infants

BACKGROUND

Umbilical cord blood culture (UCBC) may have a diagnostic utility for early onset sepsis (EOS) detection in preterm infants. It may prevent sampling the newborn and collect a higher volume of blood for pathogenic identification.

METHODS

Retrospective analysis at a tertiary care center in Canada of preterm infants ≤ 34 0/7 weeks' gestation with UCBC taken at birth.

RESULTS

Of 505 admitted infants, 195 had UCBC. 170 UCBCs were negative; 44 of these had also negative neonatal blood culture (NBC). No infants with negative UCBC showed EOS symptoms in the first week of life. 25 UCBCs were positive: 18 were contaminants (all with negative NBC) and 7 were confirmed as EOS. 18 infants with UCBC contaminants remained asymptomatic. 7 EOS cases were identified, with varying bacteriological profiles; 5 displayed sepsis symptoms while 2 were asymptomatic. Risk of EOS increased with prolonged rupture of membranes.

CONCLUSIONS

UCBC effectively detected EOS establishing it as a method with possibly better diagnostic performance than NBC in high-risk neonates. Further studies are needed to improve UCBC technique and lower contamination rates.

IMPACT

Umbilical cord blood culture has a higher bacterial identification rate than peripheral venous blood culture for the early identification of early-onset sepsis in preterm infants. Umbilical cord blood cultures that showed no growth were reliable predictors of not developing early onset sepsis. Umbilical cord blood culture should be considered as part of the evaluation for early onset sepsis in the preterm infants.

Use of Rapid Molecular Polymerase Chain Reaction in Early Detection of Bacteremia in Neonates Prior to Blood Culture Positivity: A Pilot Study

OBJECTIVE

There has been national strive to decrease the time needed to identify microorganisms in blood culture samples to reduce antibiotic use. This study evaluated rapid molecular polymerase chain reaction (PCR) use in identifying microorganisms in negative culture bottles from neonates with suspected bacterial blood stream infection at 20 to 24 hours of incubation.

STUDY DESIGN

All blood specimens from neonates with suspected blood stream infection were included. Specimens were incubated using a standard blood culturing instrument that would flag positive if bacterial growth was detected. If the specimen was flagged positive at <20 hours, it was tested by PCR and plated for identification as per standard protocol. In our design, if specimen was not flagged at 20 hours of incubation, the bottle was sterilely accessed and a sample was obtained for PCR testing. The bottle would be returned for incubation for 120 hours or until flagged positive.

RESULTS

A total of 192 blood specimens were included. Four specimens flagged positive at <20 hours and were all found to be positive by PCR. All other samples did not flag positive by 20 hours of incubation and were tested by PCR between 20 and 24 hours. One sample tested positive via PCR at 21.6 hours then flagged positive on the culturing instrument at 23.5 hours. All other specimens were negative by PCR and remained culture negative at 120 hours. The positive and negative predictive value of PCR verified by blood culture were both equal to 1.0.

CONCLUSION

Using rapid molecular PCR on blood culture specimens at 20 to 24 hours of incubation provides 100% true negative results possibly allowing providers to discontinue antibiotics at 24 hours.

KEY POINTS

· Antibiotic overuse leads to adverse neonatal outcomes.. · Molecular PCR may have true negative results.. · Larger study is needed to discontinue antibiotics earlier..

A multi-pronged approach to improve blood culture diagnostics in different clinical departments: a single-centre experience

PURPOSE

Blood culture (BC) diagnostics are influenced by many factors. We performed a targeted interdisciplinary analysis to analyse effects of various measures on BC diagnostics performance.

METHODS

A diagnostic stewardship initiative was conducted at two intervention and two control wards in a German tertiary level hospital. The initiative comprised staff training on the correct indications and sampling for BC, implementation of information cards, labels to identify the collection site, regular BC bottle feedback including the number of bottles, filling volumes and identified pathogens; and the use of a specific sampling device (BD Vacutainer®). Before and after the interventions, two three-month measurement periods were performed, as well as a one-month follow-up period to assess the sustainability of the conducted measures.

RESULTS

In total, 9362 BC bottles from 787 patients were included in the analysis. The number of BCs obtained from peripheral venous puncture could be increased at both intervention wards (44.0 vs. 22.2%, 58.3 vs. 34.4%), while arterial sampling could be reduced (30.6 vs. 4.9%). A total of 134 staff members were fully trained. The intervention led to a considerable increase in BC knowledge (from 62.4 to 79.8% correct answers) with differences between the individual professional groups. Relevant reduced contamination rates could be detected at both intervention wards.

CONCLUSIONS

As knowledge on the correct BC sampling and strategies to reduce contamination varies considerably between clinical departments and healthcare professionals, a targeted training should be adapted to the specific needs of the individual professional groups. An additional filling device is not necessary.

Role of diagnostic tests for sepsis in children: a review

Paediatric sepsis has a significant global impact and highly heterogeneous clinical presentation. The clinical pathway encompasses recognition, escalation and de-escalation. In each aspect, diagnostics have a fundamental influence over outcomes in children. Biomarkers can aid in creating a larger low-risk group of children from those in the clinical grey area who would otherwise receive antibiotics 'just in case'. Current biomarkers include C reactive protein and procalcitonin, which are limited in their clinical use to guide appropriate and rapid treatment. Biomarker discovery has focused on single biomarkers, which, so far, have not outperformed current biomarkers, as they fail to recognise the complexity of sepsis. The identification of multiple host biomarkers that may form a panel in a clinical test has the potential to recognise the complexity of sepsis and provide improved diagnostic performance. In this review, we discuss novel biomarkers and novel ways of using existing biomarkers in the assessment and management of sepsis along with the significant challenges in biomarker discovery at present. Validation of biomarkers is made less meaningful due to methodological heterogeneity, including variations in sepsis diagnosis, biomarker cut-off values and patient populations. Therefore, the utilisation of platform studies is necessary to improve the efficiency of biomarkers in clinical practice.

Effect of Serial Clinical Observation Complemented by Point-of-Care Blood Culture Volume Verification on Antibiotic Exposure in Newborns

Objective. This study evaluated the effects of serial clinical observation strategy complemented by point-of-care verification of blood culture volume in managing term and near-term newborns at risk for early-onset sepsis. Methods. We used a "before-and-after" approach. Infants born at ≥35 0/7 weeks' gestation were eligible. Our strategy was based on serial clinical observation complemented with point-of-care verification of blood culture volume. Two separate 12-month periods were analyzed. The number of infants exposed to antibiotics started during the first 3 days of life was compared before and after introducing the strategy. Results. During the post-intervention period, 0.6% of infants received antibiotic therapy, compared to 4.1% during the pre-intervention period (P < .001; relative risk [RR]: 0.15; 95% CI: 0.08-0.28). Conclusion. Serial clinical observation complemented with verification of blood culture volume might reduce antibiotic utilization in newborns in the early postnatal period.

The Yield of One vs. Two Blood Cultures in Children: Under-Detection and Over-Testing

We aimed to determine whether obtaining two blood cultures (BCs) instead of one improved the detection of bloodstream infections (BSIs) in children. For this descriptive study, we used surveillance data collected in 2019-2021 from all Israeli hospitals serving children. The sample included 178,702 culturing episodes. One BC was taken in 90.1% of all episodes and 98.2% of episodes in the emergency department. A true pathogen was detected in 1687/160,964 (1.0%) of single-culture episodes and 1567/17,738 (8.9%) of two-culture episodes (p < 0.001). The yield was significantly different even when considering only the first BC in two-culture episodes: 1.0% vs. 7.5%. Among 1576 two-culture episodes that were positive for a true pathogen, the pathogen was detected only in the second culture in 252 (16.0%). We estimated that if a second culture had been taken in all episodes, an additional 343 BSIs by a true pathogen would have been detected. Among 1086 two-culture episodes with commensal bacteria, the second BC was sterile in 530 (48.8%), suggesting contamination. A commensal was isolated in 3094/4781 (64.7%) positive single-culture episodes, which could represent BSI or contamination. The yield of a single BC bottle was low, reflecting both lower sensitivity of a single bottle and the taking of single bottles in patients with a low probability of BSI.

Switch from intravenous-to-oral antibiotics in neonatal probable and proven early-onset infection: a prospective population-based real-life multicentre cohort study

OBJECTIVE

To evaluate the implementation of switch from intravenous-to-oral antibiotic therapy with amoxicillin in neonates with early-onset infection (EOI).

DESIGN, SETTING AND PATIENTS

A population-based multicentre cohort study. All term-born neonates with EOI were prospectively included between 1 December 2018 to 30 November 2020.

INTERVENTION

Intravenous-to-oral switch antibiotic therapy in clinically stable neonates.

MAIN OUTCOME MEASURES

The primary outcome was readmission due to infection. Secondary outcomes were days of hospitalisation and antibiotic use in the pre-implementation versus post implementation period.

RESULTS

During 2 years, 835 neonates commenced antibiotics for EOI (1.5% (95% CI 1.4% to 1.6%)) of all term live births). Of those, 554 (66%) underwent a full course of treatment. There were 23 episodes of culture-proven infection (0.42 per 1000 term live births (95% CI 0.27 to 0.63)). A total of 478 of 531 (90%) neonates with probable infection underwent switch therapy. None was readmitted due to infection. The median duration of hospitalisation was 3.0 days (IQR 2.5-3.5) and 7.4 days (IQR 7.0-7.5) in the switch and intravenous therapy groups, respectively. According to antibiotic surveillance data, 1.2% underwent a full course of treatment following implementation of oral switch therapy (2019-2020), compared with 1.2% before (2017-2018).

CONCLUSION

In clinical practice, switch therapy was safe and used in 9 of 10 neonates with probable EOI. Knowledge of the safety of antibiotic de-escalation is important as home-based oral therapy ameliorates the treatment burden for neonates, caregivers and healthcare systems. Despite the ease of oral administration, implementation of switch therapy did not increase the overall use of antibiotics.

Insight Into Neonatal Sepsis: An Overview

There are approximately 1.3 million cases of neonatal sepsis reported worldwide with deaths occurring more commonly in preterm and low-weight newborns. Neonatal sepsis is the third major cause of neonatal deaths resulting in 203,000 deaths per year. It is divided into two subtypes based on time of occurrence: early-onset neonatal sepsis (ENS), occurring within the first 72 hours of birth usually due to perinatal risk factors, and late-onset neonatal sepsis (LOS) usually occurring after the first week of life and up to 28th day of life. There are many complications associated with neonatal sepsis including septic shock, multiple organ failure, and death. It is vital for clinicians to know the signs and symptoms of neonatal sepsis in order to diagnose it early. Preventive measures, early diagnosis, appropriate antibiotic administration, timely supportive management, and the establishment of efficient management are vital in the prevention of severe complications or death. In this review, we aim to provide the most up-to-date information regarding risk factors, pathophysiology, signs and symptoms, diagnosis, and treatment of neonatal sepsis. We discuss the maternal and neonatal risk factors involved in the pathogenesis of neonatal sepsis and the signs and symptoms of early and late neonatal sepsis. We focus on the different pathogens involved and the markers used in the diagnosis and treatments available for each.

Performance of 11 Host Biomarkers Alone or in Combination in the Diagnosis of Late-Onset Sepsis in Hospitalized Neonates: The Prospective EMERAUDE Study

Despite the high prevalence of late-onset sepsis (LOS) in neonatal intensive care units, a reliable diagnosis remains difficult. This prospective, multicenter cohort study aimed to identify biomarkers early to rule out the diagnosis of LOS in 230 neonates ≥7 days of life with signs of suspected LOS. Blood levels of eleven protein biomarkers (PCT, IL-10, IL-6, NGAL, IP-10, PTX3, CD14, LBP, IL-27, gelsolin, and calprotectin) were measured. Patients received standard of care blinded to biomarker results, and an independent adjudication committee blinded to biomarker results assigned each patient to either infected, not infected, or unclassified groups. Performances of biomarkers were assessed considering a sensitivity of at least 0.898. The adjudication committee classified 22% of patients as infected and all of these received antibiotics. A total of 27% of the not infected group also received antibiotics. The best biomarkers alone were IL-6, IL-10, and NGAL with an area under the curve (95% confidence interval) of 0.864 (0.798-0.929), 0.845 (0.777-0.914), and 0.829 (0.760-0.898), respectively. The best combinations of up to four biomarkers were PCT/IL-10, PTX3/NGAL, and PTX3/NGAL/gelsolin. The best models of biomarkers could have identified not infected patients early on and avoided up to 64% of unjustified antibiotics. At the onset of clinical suspicion of LOS, additional biomarkers could help the clinician in identifying non-infected patients.

Point-of-Care Verification of Blood Culture Volume in Neonates: A Feasibility Trial

BACKGROUND

Blood cultures remain the gold standard for the diagnosis of sepsis. However, volumes of blood submitted for cultures often do not match the recommended values. We propose a simple intervention aimed to verify the volume of blood sampled using a scale. This study was undertaken in preparation for a future, multicenter, pre- and post-intervention trial. Our primary objective was to test the feasibility (uptake and retention) of this future intervention.

MATERIALS AND METHODS

This study was conducted at a neonatal department in Warsaw, Poland, over a period of eight months (May to December 2020). Before starting the study, we undertook an educational intervention focused on obtaining adequate blood volumes for culture. The culture bottles that were weighed in advance were distributed in all blood collection areas. Blood volume was verified by weighing the bottle immediately after blood inoculation. The calculated value was communicated to the collecting clinician and recorded. The primary outcome measure was the percentage of blood culture submissions for which the blood volume inoculated into the bottles was determined by weighing.

RESULTS

During the study period, 244 blood samples were collected for culture, out of which 205 samples were weighed (84.0%, CI95 [78.8% to 88.4%]). This high proportion remained stable throughout the study period. We have not observed any adverse events related to the study.

CONCLUSIONS

The point-of-care verification of blood culture volume using a scale was feasible to implement. Since we have met our pre-established criterion for success, a future, definitive trial is likely to proceed.

Clinical Application of a Multiplex Droplet Digital PCR in the Rapid Diagnosis of Children with Suspected Bloodstream Infections

Droplet digital PCR (ddPCR) recently has been shown to be a potential diagnostic tool for adults with bloodstream infections (BSIs); however, its application in children remains obscure. In this study, 76 blood samples of children with suspected BSIs were synchronously detected by traditional blood cultures (BCs) and ddPCRs. Our team validated the diagnostic performance of ddPCR including sensitivity, specificity, and positive and negative predictive values. The 76 pediatric patients from the hematology department (67.1%), the pediatric intensive care unit (PICU, 27.6%), and other departments (5.2%) were enrolled. The positive rate of ddPCR results was 47.9%, whereas that for BC was 6.6%. In addition, the time consumption of ddPCR was shorter, only for 4.7 ± 0.9 h, in comparison with the detection timing of BC (76.7 ± 10.4 h, p < 0.01). The levels of agreement and disagreement between BC and ddPCR were 96.1% and 4.2%, and the negative agreement reached 95.6%. The sensitivity of ddPCR was 100%, with corresponding specificities ranging from 95.3 to 100.0%. In addition, a total of nine viruses were identified by ddPCR. In China, the multiplexed ddPCR first could be a tool for the rapid and accurate diagnosis of children with suspected BSIs and can be an early indicator of the possibility of viraemia in children with immunosuppression.

Potential of Molecular Culture in Early Onset Neonatal Sepsis Diagnosis: A Proof of Principle Study

Delay in the time-to-positivity of a peripheral blood culture (PBC), the gold standard for early onset neonatal sepsis (EOS) diagnosis, has resulted in excessive use of antibiotics. In this study, we evaluate the potential of the rapid Molecular Culture (MC) assay for quick EOS diagnosis. In the first part of this study, known positive and spiked blood samples were used to assess the performance of MC. In the in vivo clinical study, the second part of this study, all infants receiving antibiotics for suspicion of EOS were included. At initial EOS suspicion, a blood sample was collected for PBC and MC. MC was able to detect bacteria present in the spiked samples even when the bacterial load was low. In the clinical study, MC was positive in one infant with clinical EOS (Enterococcus faecalis) that was not detected by PBC. Additionally, MC was positive in two infants without clinical sepsis (Streptococcus mitis and multiple species), referred to as contamination. The other 37 samples were negative both by MC and PBC. MC seems to be able to detect bacteria even when the bacterial load is low. The majority of MC and PBC results were comparable and the risk for contamination and false positive MC results seems to be limited. Since MC can generate results within 4 h following sampling compared with 36-72 h in PBC, MC may have the potential to replace conventional PBC in EOS diagnostics in order to guide clinicians on when to discontinue antibiotic therapy several hours after birth.

Temperature threshold in the screening of bacterial infections in young infants with hypothermia

BACKGROUND

Young infants with hypothermia presenting to the emergency department (ED) are at risk for serious bacterial infections (SBI), however there is no consensus temperature to prompt evaluation for SBI among these children. We sought to statistically derive a temperature threshold to guide detection of SBI in young infants with hypothermia presenting to the ED.

METHODS

We performed a cross-sectional study of infants ≤90 days old presenting to four academic paediatric EDs in the United States of America from January 2015 through December 2019 with a rectal temperature of ≤36.4°C. Our primary outcomes were SBI, defined as urinary tract infection (UTI), bacteraemia and/or bacterial meningitis, and invasive bacterial infections (IBI, limited to bacteraemia and/or bacterial meningitis). We constructed receiver operating characteristic (ROC) curves to evaluate an optimally derived cutpoint for minimum ED temperature and presence of SBI or IBI.

RESULTS

We included 3376 infants, of whom SBI were found in 62 (1.8%) and IBI in 16 (0.5%). The most common infection identified was Escherichia coli UTI. Overall, cohort minimum median temperature was 36.2°C (IQR 36.0°C-36.4°C). Patients with SBI and IBI had lower median temperatures, 35.8°C (IQR 35.8°C-36.3°C) and 35.4°C (IQR 35.7°C-36.3°C), respectively, compared with those without corresponding infections (both p<0.05). Using an outcome of SBI, the area under the ROC curve (AUROC) was 61.0% (95% CI 54.1% to 67.9%). At a cutpoint of 36.2°C, sensitivity was 59.7% and specificity was 59.2%. When using an outcome of IBI, the AUROC was 65.9% (95% CI 51.1% to 80.6%). Using a cutpoint of 36.1°C in this model resulted in a sensitivity of 68.8% and specificity of 60.1%.

CONCLUSION

Young infants with SBI and IBI presented with lower temperatures than infants without infections. However, there was no temperature threshold to reliably identify SBI or IBI. Further research incorporating clinical and laboratory parameters, in addition to temperature, may help to improve risk stratification for these vulnerable patients.

Density of antibiotic use and infectious complications in pediatric allogeneic hematopoietic cell transplantation

BACKGROUND

Antibiotics, while an essential component of supportive care in allogeneic hematopoietic cell transplantation (allo-HCT), can have adverse effects and select for antibiotic resistance. Understanding of patterns of use will inform antimicrobial stewardship (AMS) interventions.

METHODS

Retrospective, single-center cohort of children undergoing first allo-HCT (n = 125). Antibiotic prescription and infection data were included from the date conditioning was commenced until 30 days post allo-HCT. Antibiotic use was reported as length of therapy (LOT) (number of days a patient received an antibiotic) and days of therapy DOT (aggregating all antibiotics prescribed per day). Infections were classified as microbiologically documented infection (MDI) or clinically documented infections.

RESULTS

At least one course of antibiotics was administered to 124 (99%) patients. The LOT was 636 per 1000 patient days and DOT was 959 per 1000 patient days. The median duration of cumulative antibiotic exposure per patient was 24 days (interquartile range [IQR] 20-30 days). There were 131 days of fever per 1000 patient days with patients febrile for a median of 4 days (IQR 1-7 days). Piperacillin-tazobactam was used for 116 (94%) of patients with an LOT of 532 per 1000 patient days. A total of 119 MDI episodes occurred in 74 (59%) patients, including blood stream infection in 30 (24%) and a proven/probable invasive fungal infection in 4 (3%).

CONCLUSION

Pediatric HCT patients receive prolonged courses of broad-spectrum antibiotics relative to the frequency of fever and bacterial infections. This study has identified opportunities for AMS intervention to improve outcomes for our HCT patients.

Biomarkers and their association with bacterial illnesses in hypothermic infants

OBJECTIVES

To describe the association of biomarkers with serious bacterial infection (SBI; urinary tract infection [UTI], bacteremia and/or bacterial meningitis) in hypothermic infants presenting to the emergency department (ED).

METHODS

We performed a cross sectional study in four academic pediatric EDs from January 2015 through December 2019, including infants ≤90 days old presenting with a rectal temperature of ≤36.4 °C. We constructed receiver operating characteristic (ROC) curves to evaluate the accuracy of blood biomarkers including white blood cell count (WBC), absolute neutrophil count (ANC) and platelets for identifying SBI, with exploratory analyses evaluating procalcitonin and band counts.

RESULTS

Among 850 included infants (53.5% males; median days of age 13 [IQR 5-58 days]), SBI were found in 55 (6.5%). For infants with SBI, the area under the curve (AUC; 95% confidence interval) for WBC was 0.70 (0.61-0.78) with sensitivity 0.64 (0.50-0.74) and specificity 0.77 (0.74-0.80). The AUC for ANC was 0.77 (0.70-0.84) with sensitivity 0.69 (0.55-0.81) and specificity 0.77 (0.74-0.8). For platelets, the AUC was 0.6 (0.52-0.67) with sensitivity 0.73 (0.59-0.84) and specificity 0.5 (0.46-0.53). Both the WBC and ANC were minimally accurate for identifying hypothermic infants with SBI. When looking at the accuracy of these biomarkers for identifying invasive bacterial infection (IBI; bacteremia and/or bacterial meningitis), ANC again showed minimal accuracy with an AUC of 0.70 (0.55-0.85).

CONCLUSIONS

Biomarkers commonly used as part of an infectious workup are generally poor at identifying SBI in hypothermic infants. Our findings from this cohort of hypothermic infants are similar to those reported from febrile infants, suggesting similarities in the bioresponse to infection between hypothermic and febrile infants. Additional research is required to improve risk stratification for hypothermic infants, and to better guide evaluation and management.

A positive blood culture is associated with a lower haemoglobin increment in hospitalized patients after red blood cell transfusion

BACKGROUND AND OBJECTIVES

Abundant clinical evidence supports the safety of red blood cell (RBC) concentrates for transfusion irrespective of storage age, but still, less is known about how recipient characteristics may affect post-transfusion RBC recovery and function. Septic patients are frequently transfused. We hypothesized that the recipient environment in patients with septicaemia would blunt the increase in post-transfusion blood haemoglobin (Hb). The main objective was to compare the post-transfusion Hb increment in hospitalized patients with or without a positive blood culture.

MATERIALS AND METHODS

A retrospective cohort study using data from the Transfusion Research, Utilization, Surveillance, and Tracking database (TRUST) was performed. All adult non-trauma in-patients transfused between 2010 and 2017 with ≥1 RBC unit, and for whom both pre- and post-transfusion complete blood count and pre-transfusion blood culture data were available were included. A general linear model with binary blood culture positivity was fit for continuous Hb increment after transfusion and was adjusted for patient demographic parameters and transfusion-related covariates.

RESULTS

Among 210,263 admitted patients, 6252 were transfused: 596 had positive cultures, and 5656 had negative blood cultures. A modelled Hb deficit of 1.50 g/L in blood culture-positive patients was found. All covariates had a significant effect on Hb increment, except for the age of the transfused RBC.

CONCLUSION

Recipient blood culture positivity was associated with a statistically significant but modestly lower post-transfusion Hb increment in hospitalized patients. In isolation, the effect is unlikely to be clinically significant, but it could become so in combination with other recipient characteristics.

Perinatal bacterial colonization and neonatal early-onset sepsis: A case-control study

BACKGROUND

The utility of determining maternal-neonatal surface colonization as detected by standard microbiological cultures around the time of birth is unclear. The aim of this study is to evaluate the association between maternal and neonatal surface colonization at birth and neonatal early onset sepsis (EOS).

OBJECTIVE

To investigate the association of white matter hyperintensities (WMHs) present in the brain with AD CSF biomarker levels.

METHODS

We conducted a case-control study of newborns admitted to the neonatal department of a referral women's and children's hospital from 2009 to 2017. Cases were infants with blood-culture-confirmed EOS (<3 days of life), and controls were infants without EOS randomly chosen based on the cases' date of birth. Maternal genitourinary and neonatal ear swab cultures were used to determine bacterial surface colonization status.

RESULTS

Fifty-one infants were diagnosed with EOS during the study period, where Escherichia coli (45%), and Group B Streptococcus (23%) accounted for 68% of infecting organisms. Compared to infants without EOS, those infected were more likely to have surface colonization of the mothers (60% vs 40%, p = 0.048) and infants (90% vs 11%, p < 0.001). In univariate analysis, chorioamnionitis [7.1 (95% CI 2.9, 16.8)], small-for-gestational-age [OR 0.08 (95% CI 0.02, 0.4)], exposure to antibiotics around time of birth [2.3 (95% CI 1.0, 5.1)], maternal surface colonization [2.2 (95% CI 1.0, 4.9)] and neonatal surface colonization [23.5 (95% CI 7.3, 76.1)] were significantly associated with EOS. Adjusting for potential confounders, neonatal colonization remained significantly associated with neonatal EOS [AOR 15.0 (95% CI 3.5, 64.2), p < 0.001].

CONCLUSION

In our setting with predominant Gram-negative EOS, neonatal colonization but not maternal colonization was significantly associated with EOS in the newborn.

Efficacy and safety of switching from intravenous to oral antibiotics (amoxicillin-clavulanic acid) versus a full course of intravenous antibiotics in neonates with probable bacterial infection (RAIN): a multicentre, randomised, open-label, non-inferiority trial

BACKGROUND

Switching from intravenous antibiotic therapy to oral antibiotic therapy among neonates is not yet practised in high-income settings due to uncertainties about exposure and safety. We aimed to assess the efficacy and safety of early intravenous-to-oral antibiotic switch therapy compared with a full course of intravenous antibiotics among neonates with probable bacterial infection.

METHODS

In this multicentre, randomised, open-label, non-inferiority trial, patients were recruited at 17 hospitals in the Netherlands. Neonates (postmenstrual age ≥35 weeks, postnatal age 0-28 days, bodyweight ≥2 kg) in whom prolonged antibiotic treatment was indicated because of a probable bacterial infection, were randomly assigned (1:1) to switch to an oral suspension of amoxicillin 75 mg/kg plus clavulanic acid 18·75 mg/kg (in a 4:1 dosing ratio, given daily in three doses) or continue on intravenous antibiotics (according to the local protocol). Both groups were treated for 7 days. The primary outcome was cumulative bacterial reinfection rate 28 days after treatment completion. A margin of 3% was deemed to indicate non-inferiority, thus if the reinfection rate in the oral amoxicillin-clavulanic acid group was less than 3% higher than that in the intravenous antibiotic group the null hypothesis would be rejected. The primary outcome was assessed in the intention-to-treat population (ie, all patients who were randomly assigned and completed the final follow-up visit on day 35) and the per protocol population. Safety was analysed in all patients who received at least one administration of the allocated treatment and who completed at least one follow-up visit. Secondary outcomes included clinical deterioration and duration of hospitalisation. This trial was registered with ClinicalTrials.gov, NCT03247920, and EudraCT, 2016-004447-36.

FINDINGS

Between Feb 8, 2018 and May 12, 2021, 510 neonates were randomly assigned (n=255 oral amoxicillin-clavulanic group; n=255 intravenous antibiotic group). After excluding those who withdrew consent (n=4), did not fulfil inclusion criteria (n=1), and lost to follow-up (n=1), 252 neonates in each group were included in the intention-to-treat population. The cumulative reinfection rate at day 28 was similar between groups (one [<1%] of 252 neonates in the amoxicillin-clavulanic acid group vs one [<1%] of 252 neonates in the intravenous antibiotics group; between-group difference 0 [95% CI -1·9 to 1·9]; p_{non-inferiority}<0·0001). No statistically significant differences were observed in reported adverse events (127 [50%] vs 113 [45%]; p=0·247). In the intention-to-treat population, median duration of hospitalisation was significantly shorter in the amoxicillin-clavulanic acid group than the intravenous antibiotics group (3·4 days [95% CI 3·0-4·1] vs 6·8 days [6·5-7·0]; p<0·0001).

INTERPRETATION

An early intravenous-to-oral antibiotic switch with amoxicillin-clavulanic acid is non-inferior to a full course of intravenous antibiotics in neonates with probable bacterial infection and is not associated with an increased incidence of adverse events.

FUNDING

The Netherlands Organization for Health Research and Development, Innovatiefonds Zorgverzekeraars, and the Sophia Foundation for Scientific Research.

The Value of Perinatal Factors, Blood Biomarkers and Microbiological Colonization Screening in Predicting Neonatal Sepsis

Background: Neonatal sepsis is one of the most important causes of elevated morbidity and mortality rates in neonatal intensive care units worldwide. While the clinical manifestations of neonatal sepsis tend to be nonspecific, its rapid development and life-threatening potential call for reliable markers for early detection. Methods: We conducted a retrospective single-center study including all neonates suspected of having developed neonatal sepsis from 2013 to 2016. Perinatal and clinical characteristics as well as microbiological and laboratory findings were evaluated. Neonatal sepsis was defined as either culture-proven sepsis (positive blood culture) or clinical sepsis (at least one symptom and elevated C-reactive protein (CRP) concentrations within 72 h with negative blood culture). We further differentiated between early-onset (EOS) and late-onset (LOS) sepsis. Results: Microbiological colonization screening by throat and rectal swabs frequently did not detect the organism that subsequently caused the sepsis. Depending on the age of the newborn with sepsis (EOS or LOS), associations between different anamnestic and clinical factors (prenatal or postnatal ones) were found. In particular, the central−peripheral temperature difference showed a strong association with LOS. Laboratory results useful for the early detection of neonatal sepsis included interleukin-6 (IL-6) and CRP concentrations. Conclusions: Elevated IL-6 >100 ng/L was a strong marker for neonatal sepsis. When choosing the antibiotics for treatment, data from microbiological colonization screening should be considered but not solely relied on. Some indicators of infection also depended on postnatal age.

Serial Measurement of Interleukin-6 Enhances Chance to Exclude Early-Onset Sepsis in Very Preterm Infants

The aim of this retrospective study was to evaluate the reliability of peak interleukin-6 (IL-6) level within 24 hours after delivery as a predictor for early-onset sepsis (EOS) in very preterm neonates. Interleukin-6 was assessed at 2 hours and at 12 to 24 hours after delivery. The highest level was considered a peak value. The definition of EOS was based on positive blood culture and clinical signs of infection or negative blood culture, clinical signs of infection, and C-reactive protein >10 mg/L. Among 445 enrolled infants, 53 developed EOS. A peak IL-6 level of more than 200 ng/L had a sensitivity of 89% and specificity of 77% for the presence of EOS. The negative predictive value was 98%. Receiver operating characteristics curve had area under the curve of 0.92. Peak IL-6 is a reliable marker of systemic inflammatory response and might be useful to exclude EOS within the first 24 hours.

Validity of serum and urinary hepcidin as biomarkers for late-onset sepsis in premature infants

Background:

Sepsis remains one of the leading causes of neonatal morbidity and mortality, particularly among premature infants. Blood culture is the ‘gold standard’ for the diagnosis of neonatal sepsis but is associated with several pitfalls.

Aim of the work:

We aim to evaluate the validity of measuring serum (S.Hep) and urinary hepcidin (U.Hep) concentrations as diagnostic biomarkers for late-onset sepsis (LOS) in preterm infants.

Patients and Methods:

The current case-control study included 73 cases of clinically and laboratory confirmed late-onset sepsis as the ‘case group’ and 50 nonseptic premature infants of comparable age and sex as the ‘control group’. S.Hep and U.Hep concentrations were evaluated at enrollment (acute sample) and after 1 week of treatment (convalescent sample).

Results:

Patients had a statistically significant higher concentration of both S.Hep and U.Hep as compared with nonseptic controls (p = 0.0001). Similarly, a significant reduction of both S.Hep and U.Hep was detected after 1 week of treatment (p = 0.001). A cut-off value of ⩾ 94.8 ng/ml of S.Hep and ⩾ 264 ng/mg of U.Hep/urinary creatinine showed high sensitivity, specificity, and positive predictive value in the diagnosis of neonatal LOS.

Conclusions:

Both S.Hep and U.Hep can function as promising accurate and rapid surrogate tests for the diagnosis of LOS. U.Hep measurement has the advantage of being noninvasive, with no hazards of phlebotomy, and is less variable throughout the day.

Distribution of Presepsin, Krebs von den Lungen 6, and Surfactant Protein A in Umbilical Cord Blood

Presepsin is an early indicator of infection, and Krebs von den Lungen 6 (KL-6) and Surfactant Protein A (SP-A) are related to the pathogenesis of pulmonary infection and fibrosis. This study aimed to establish reference intervals (RIs) of presepsin, KL-6, and SP-A levels and to evaluate the possible influence of neonatal and maternal factors on presepsin, KL-6, and SP-A levels in umbilical cord blood (UCB). Among a total of 613 UCB samples, the outliers were removed. The RIs for presepsin, KL-6, and SP-A levels were defined using non-parametric percentile methods according to the Clinical and Laboratory Standards Institute guidelines (EP28-A3C). These levels were analyzed according to neonatal and maternal factors: neonatal sex, gestational age (GA), birth weight (BW), Apgar score, delivery mode, the presence of premature rupture of membranes (PROM), gestational diabetes mellitus (GDM), and pre-eclampsia. Presepsin, KL-6, and SP-A levels showed non-parametric distributions and left-skewed histograms. The RIs of presepsin, KL-6, and SP-A levels were 64.9–428.3 pg/mL, 43.0–172.0 U/mL, and 2.1–36.1 ng/mL, respectively. Presepsin, KL-6, and SP-A levels did not show significant differences according to sex, GA, BW, Apgar score, delivery mode, PROM, GDM, and pre-eclampsia. The median level and 97.5th centile RI of KL-6 showed a slight increase with increased GA. We established RIs for presepsin, KL-6, and SP-A levels in large-scaled UCB samples. Further investigation would be needed to determine the clinical significance.

Umbilical cord blood culture in neonatal early-onset sepsis: a systematic review and meta-analysis

BACKGROUND

Peripheral blood culture (PBC) is considered the gold standard for diagnosis of neonatal early-onset sepsis (EOS), but its diagnostic value can be questioned. We aimed to systematically asses the diagnostic test accuracy (DTA) of umbilical cord blood culture (UCBC) for EOS.

METHODS

A systematic literature search was performed in PubMed, Embase, Web of Science, and the Cochrane Library. Studies performing UCBC for the diagnosis of EOS were included.

RESULTS

A total of 1908 articles were screened of which 17 were included. Incidences of positive PBC and UCBC were low in all studies. There was a large heterogeneity in the consistency between positive PBC and UCBC outcomes. PBC had a pooled sensitivity of 20.4% (95% CI 0.0-40.9) and specificity of 100.0% (95% CI 100.0-100.0) compared to 42.6% (95% CI 12.7-72.4%) and 97.8% (95% CI 93.1-100.0) of UCBC for clinical EOS, defined as clinical sepsis regardless of PBC outcomes.

CONCLUSIONS

This systematic review shows that, compared to PBC, UCBC has higher sensitivity and comparable specificity for clinical EOS and might be considered as diagnostic test for EOS. Due to the limited number of studies, low incidences of EOS cases, and the imperfect reference standards for EOS, results should be interpreted cautiously.

IMPACT

This is the first systematic review and meta-analysis investigating the diagnostic test accuracy of umbilical cord blood culture for neonatal early-onset sepsis. Peripheral blood culture is considered the gold standard for diagnosis of neonatal early-onset sepsis, but its value for this specific diagnosis can be questioned. Umbilical cord blood culture has higher sensitivity and comparable specificity for diagnosis of neonatal early-onset sepsis compared to peripheral blood culture, circumventing the risk for iatrogenic anemia and consequently might be used as a diagnostic tool for early-onset sepsis. Quality of evidence was regarded as low due to imperfect diagnostic methods of neonatal early-onset sepsis.

Restrictive prescription of antibiotics in preterm infants with premature rupture of membranes

BACKGROUND

In preterm infants with premature rupture of membranes, antibiotic treatment is frequently started but rates of early onset sepsis are lower. In line with national guidelines, a stratified approach in the decision to start antibiotic treatment using maternal history, clinical impression and biomarkers has been implemented in our level III neonatal center and its results are evaluated.

METHODS

Retrospective cohort study of all preterm newborns with rupture of membranes at least 1 h prior to delivery admitted to our tertiary neonatal intensive care unit. Data on antibiotic exposure, mortality and major neonatal complications were extracted from the electronic patient charts to evaluate the effects and safety of our stratified approach.

RESULTS

Four hundred fifty-six infants met the inclusion criteria. 120 (26%) received primary antibiotics whereas 336 (74%) did not. Of those receiving primary antibiotics, 13 (11%) had a blood culture positive sepsis, 46 (38%) met the criteria of clinical sepsis and in 61 (51%) sepsis was ruled out and antibiotics were stopped after 48-96 h. All infants with blood culture positive sepsis were identified and treated within the first 24 h of life using this approach. None of the 336 infants who were not started on antibiotics primarily needed antibiotic therapy within the first 5 days of life. There were no deaths or major neonatal complications in the group that did not receive empiric antibiotics.

CONCLUSIONS

Our stratified approach for preterm infants with premature rupture of membranes allows a safe reduction of antibiotic exposure even in this high risk population. As a result, only 25% of high risk preterm newborns are treated with antibiotics of which more than half receive less than 5 days of treatment. To treat one infant with blood culture positive sepsis, only 9 infants receive empiric antibiotics.

Systematic review of host genomic biomarkers of invasive bacterial disease: Distinguishing bacterial from non-bacterial causes of acute febrile illness

Background

Infectious diseases play a significant role in the global burden of disease. The gold standard for the diagnosis of bacterial infection, bacterial culture, can lead to diagnostic delays and inappropriate antibiotic use. The advent of high- throughput technologies has led to the discovery of host-based genomic biomarkers of infection, capable of differentiating bacterial from other causes of infection, but few have achieved validation for use in a clinical setting.

Methods

A systematic review was performed. PubMed/Ovid Medline, Ovid Embase and Scopus databases were searched for relevant studies from inception up to 30/03/2022 with forward and backward citation searching of key references. Studies assessing the diagnostic performance of human host genomic biomarkers of bacterial infection were included. Study selection and assessment of quality were conducted by two independent reviewers. A meta-analysis was undertaken using a diagnostic random-effects model. The review was registered with PROSPERO (ID: CRD42021208462).

Findings

Seventy-two studies evaluating the performance of 116 biomarkers in 16,216 patients were included. Forty-six studies examined TB-specific biomarker performance and twenty-four studies assessed biomarker performance in a paediatric population. The results of pooled sensitivity, specificity, negative and positive likelihood ratio, and diagnostic odds ratio of genomic biomarkers of bacterial infection were 0.80 (95% CI 0.78 to 0.82), 0.86 (95% CI 0.84 to 0.88), 0.18 (95% CI 0.16 to 0.21), 5.5 (95% CI 4.9 to 6.3), 30.1 (95% CI 24 to 37), respectively. Significant between-study heterogeneity (I² 77%) was present.

Interpretation

Host derived genomic biomarkers show significant potential for clinical use as diagnostic tests of bacterial infection however, further validation and attention to test platform is warranted before clinical implementation can be achieved.

Funding

No funding received.

Excessively Prolonged Early Antibiotic Duration in Very-Low-Birth-Weight Infants: A Multicenter Prospective Cohort Study in a Developing Country

Purpose

Significant antibiotic overuse due to prolonged antibiotic duration has not draw enough attention in developing countries with high antibiotic consumption. We aimed to describe the current status of prolonged early antibiotic duration in very-low-birth-weight (VLBW) infants in a large regional multicenter cohort in China.

Patients and Methods

Institution-based prospective cohort study was conducted in all VLBW infants admitted to 16 Grade A tertiary hospitals between January 1, 2019 and December 31, 2020. Early antibiotic use was defined as antibiotic initiation within the first 3 days of life. Prolonged early antibiotic course was defined as early antibiotic initiation for more than 7 days in infants with early-onset sepsis (EOS) or more than 3 days in infants with unlikely EOS. Antibiotic use was described as days of therapy (DOT) per 1000 patient days (PD).

Results

Among 1684 eligible VLBW infants, 1544 (91.7%) infants were prescribed with prolonged early antibiotic course, including 618 infants with EOS and 926 infants with unlikely EOS. The median duration of early antibiotic course was 13 (IQR 8;20) days, with 78.0% of courses >7 days and 43.6% of courses >14 days. Total early antibiotic use was 408.3DOT/1000Pd, of which prolonged antibiotic courses accounted for 98.2% of all antibiotic use days. More than three antibiotics used, escalation antibiotic therapy, antibiotics for special use and the use of third generation cephalosporins and carbapenems were significantly common in prolonged courses compared to short courses in both infants with EOS and unlikely EOS group (P<0.05).

Conclusion

A large proportion of VLBW infants had excessively prolonged early antibiotic durations in the regional multicenter in China. Timely discontinuation of antibiotics in VLBW infants according to standardized guidelines and limit on the use of third-generation cephalosporins and carbapenems may be key drivers in reducing the antibiotic overuse in developing countries like ours.

Short time to positivity of blood culture predicts mortality and septic shock in bacteremic patients: a systematic review and meta-analysis

Background

The value of time to positivity (TTP) on diagnosis for catheter-related bloodstream infection and distinguishment on bacteria group and infection source has been investigated. However, the relationship between TTP and patient outcome requires verification, and we performed a systematic review and meta-analysis.

Methods

We searched PubMed, EMBASE, CINAHL, Cochrane Library, Web of Science for publications associated with the topic. We included studies that researched the TTP on predicting patient mortality and septic shock. Quality assessment is performed with Critical Appraisal Skills Programme (CASP). The analysis is performed using Review Manager Version 5.0.24. on articles available for data extraction on the exact population of each outcome group. The existence of publication bias was assessed by funnel plots. Statistical heterogeneity was evaluated using the Cochran Q and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${I}^{2}$$\end{document}I2 statistics. The outcome is reported as an odds ratio. PROSPERO registration: CRD42021272286.

Results

Twenty-four eligible studies were included in our study. Twenty-four in the mortality group and six in the septic shock group. Mortality is significantly associated with the short time to positivity group with an odds ratio of 2.98 (95% CI: 2.25–3.96, p-value < 0.001). The odds ratio for developing septic shock in the short TTP group is 4.06 (95% CI: 2.41–6.84, p-value < 0.001). Subgroup analysis revealed short TTP as a significant predictor of mortality and septic shock in Gram's positive and Gram's negative related bloodstream infections. TTP is not associated with mortality among patients with candidaemia.

Conclusions

Short time to positivity is a reliable marker for patient outcome in certain bacterial species. Studies concerning confounding factors such as the delay in bottle loading and other confounding factors are needed to enhance external validity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07098-8.

British Infection Association Guidelines for the Diagnosis and Management of Enteric Fever in England

Enteric fever (EF) is an infection caused by the bacteria called Salmonella Typhi or Paratyphi. Infection is acquired through swallowing contaminated food or water. Most EF in England occurs in people returning from South Asia and other places where EF is common; catching EF in England is rare. The main symptom is fever, but stomach pain, diarrhoea, muscle aches, rash and other symptoms may occur. EF is diagnosed by culturing the bacteria from blood and/or stool in a microbiology laboratory. EF usually responds well to antibiotic treatment. Depending on how unwell the individual is, antibiotics may be administered by mouth or by injection. Over the past several years, there has been an overall increase in resistance to antibiotics used to treat enteric fever, in all endemic areas. Additionally, since 2016, there has been an ongoing outbreak of drug-resistant EF in Pakistan. This infection is called extensively drug-resistant, or XDR, EF and only responds to a limited number of antibiotics. Occasionally individuals develop complications of EF including confusion, bleeding, a hole in the gut or an infection of the bones or elsewhere. Some people may continue to carry the bacteria in their stool for a longtime following treatment for the initial illness. These people may need treatment with a longer course of antibiotics to eradicate infection. Travellers can reduce their risk of acquiring EF by following safe food and water practices and by receiving the vaccine at least a few weeks before travel. These guidelines aim to help doctors do the correct tests and treat patients for enteric fever in England but may also be useful to doctors and public health professionals in other similar countries.

The Interplay between Host Defense, Infection, and Clinical Status in Septic Patients: A Narrative Review

Sepsis is a life-threatening condition that arises when the body's response to an infection injures its own tissues and organs. Despite significant morbidity and mortality throughout the world, its pathogenesis and mechanisms are not clearly understood. In this narrative review, we aimed to summarize the recent developments in our understanding of the hallmarks of sepsis pathogenesis (immune and adaptive immune response, the complement system, the endothelial disfunction, and autophagy) and highlight novel laboratory diagnostic approaches. Clinical management is also discussed with pivotal consideration for antimicrobic therapy management in particular settings, such as intensive care unit, altered renal function, obesity, and burn patients.

Using Classification Tree Analysis to Predict the Type of Infection in Preterm Neonates: Proof of Concept Study

Supplemental Digital Content is available in the text.

BACKGROUND:

Late-onset neonatal sepsis is a major complication in preterm neonates. Early identification of the type of infection could help to improve therapy and outcome depending on the suspected microorganism by tailoring antibiotic treatment to the individual patient based on the predicted organism. Results of blood cultures may take up to 2 days or may remain negative in case of clinical sepsis. Chemical biomarkers may show different patterns in response to different type of microorganisms.

OBJECTIVE:

The aim of this study was to develop, as a proof of concept, a simple classification tree algorithm using readily available information from biomarkers to show that biomarkers can potentially be used in discriminating in the type of infection in preterm neonates suspected of late-onset neonatal sepsis.

DERIVATION COHORT:

A total of 509 suspected late-onset neonatal sepsis episodes in neonates born before less than 32 weeks of gestation were analyzed. To examine model performance, 70% of the original dataset was randomly selected as a derivation cohort (n = 356; training dataset).

VALIDATION COHORT:

The remaining 30% of the original dataset was used as a validation cohort (n = 153; test dataset).

PREDICTION MODEL:

A classification tree prediction algorithm was applied to predict type of infection (defined as no/Gram-positive/Gram-negative sepsis).

RESULTS:

Suspected late-onset neonatal sepsis episodes were classified as no sepsis (80.8% [n = 411]), Gram-positive sepsis (13.9% [n = 71]), and Gram-negative sepsis (5.3% [n = 27]). When the derived classification tree was applied to the test cohort, the overall accuracy was 87.6% (95% CI, 81.3–92.4; p = 0.008). The classification tree demonstrates that interleukin-6 is the most important differentiating biomarker and C-reactive protein and procalcitonin help to further differentiate.

CONCLUSION:

We have developed and internally validated a simple, clinically relevant model to discriminate patients with different types of infection at moment of onset. Further research is needed to prospectively validate this in a larger population and assess whether adaptive antibiotic regimens are feasible.

Practice Summary of Antimicrobial Therapy for Commonly Encountered Conditions in the Neonatal Intensive Care Unit: A Canadian Perspective

Neonates are highly susceptible to infections owing to their immature cellular and humoral immune functions, as well the need for invasive devices. There is a wide practice variation in the choice and duration of antimicrobial treatment, even for relatively common conditions in the NICU, attributed to the lack of evidence-based guidelines. Early decisive treatment with broad-spectrum antimicrobials is the preferred clinical choice for treating sick infants with possible bacterial infection. Prolonged antimicrobial exposure among infants without clear indications has been associated with adverse neonatal outcomes and increased drug resistance. Herein, we review and summarize the best practices from the existing literature regarding antimicrobial use in commonly encountered conditions in neonates.

Knowledge gaps in late-onset neonatal sepsis in preterm neonates: a roadmap for future research

Late-onset neonatal sepsis (LONS) remains an important threat to the health of preterm neonates in the neonatal intensive care unit. Strategies to optimize care for preterm neonates with LONS are likely to improve survival and long-term neurocognitive outcomes. However, many important questions on how to improve the prevention, early detection, and therapy for LONS in preterm neonates remain unanswered. This review identifies important knowledge gaps in the management of LONS and describe possible methods and technologies that can be used to resolve these knowledge gaps. The availability of computational medicine and hypothesis-free-omics approaches give way to building bedside feedback tools to guide clinicians in personalized management of LONS. Despite advances in technology, implementation in clinical practice is largely lacking although such tools would help clinicians to optimize many aspects of the management of LONS. We outline which steps are needed to get possible research findings implemented on the neonatal intensive care unit and provide a roadmap for future research initiatives. IMPACT: This review identifies knowledge gaps in prevention, early detection, antibiotic, and additional therapy of late-onset neonatal sepsis in preterm neonates and provides a roadmap for future research efforts. Research opportunities are addressed, which could provide the means to fill knowledge gaps and the steps that need to be made before possible clinical use. Methods to personalize medicine and technologies feasible for bedside clinical use are described.

Neonatal blood culture inoculant volume: feasibility and challenges

BACKGROUND

Clinicians often express concerns about poor sensitivity of blood cultures in neonates resulting from inadequate inoculant volumes. Our objective was to determine the inoculant volume sent for neonatal sepsis evaluations and identify areas of improvement.

METHODS

Single-center prospective observational study of infants undergoing sepsis evaluation. Blood volume was determined by clinician documentation over 21 months, and additionally by weighing culture bottles during 12 months. Adequate volume was defined as ≥1 mL total inoculant per evaluation. For first-time evaluations, local guidelines recommend sending an aerobic-anaerobic pair with 1 mL inoculant in each.

RESULTS

There were 987 evaluations in 788 infants. Clinicians reported ≥1 mL total inoculant in 96.9% evaluations. Among 544 evaluations where bottles were weighed, 93.4% had ≥1 mL total inoculant. Very low birth weight infants undergoing evaluations >7 days after birth had the highest proportion of inadequate inoculants (14.4%). Only 3/544 evaluations and 26/1011 bottles had total inoculant <0.5 mL. Ninety evaluations had <1 mL in both aerobic and anaerobic bottles despite a total inoculant volume that allowed inoculation of ≥1 mL in one of the bottles.

CONCLUSIONS

Obtaining recommended inoculant volumes is feasible in majority of neonates. Measuring inoculant volumes can focus improvement efforts and improve test reliability.

IMPACT

Clinicians express concern about the unreliability of neonatal blood cultures because of inadequate inoculant volume. We investigated over 900 evaluations and found >90% of evaluations have ≥1 mL inoculant. Monitoring adequacy of blood culture technique can identify areas of improvement and may allay concerns about blood culture reliability. Current recommendations for adequate inoculant volume for blood cultures are met in a majority of neonates. Areas of improvement include preterm late-onset sepsis evaluations and distribution techniques during inoculation.

Clinical significance of serum miR-101-3p expression in patients with neonatal sepsis

Aim: This study aimed to evaluate the levels and functions of miR-101-3p in neonatal sepsis (NS). Materials & methods: Quantitative real-time PCR was conducted to investigate the expression of miR-101-3p and the receiver operating characteristic curve was applied to manifest its diagnostic effects. Results: miR-101-3p was increased in the NS patients and the dysregulation of miR-101-3p was associated with levels of procalcitonin, CRP, IL-8 and TNF-α. The combination of miR-101-3p and procalcitonin could function as a promising indicator in distinguishing NS patients. The silenced miR-101-3p reversed the increased levels of TNF-α and IL-8 caused by lipopolysaccharide in vitro. DUSP1 was identified as a direct target gene of miR-101-3p in NS. Conclusion: The abundance of miR-101-3p facilitated the inflammation in NS by targeting DUSP1.

Neurodevelopmental outcomes following neonatal late-onset sepsis and blood culture-negative conditions

OBJECTIVE

Determine risk of death or neurodevelopmental impairment (NDI) in infants with late-onset sepsis (LOS) versus late-onset, antibiotic-treated, blood culture-negative conditions (LOCNC).

DESIGN

Retrospective cohort study.

SETTING

24 neonatal centres.

PATIENTS

Infants born 1/1/2006-31/12/2014, at 22-26 weeks gestation, with birth weight 401-1000 g and surviving >7 days were included. Infants with early-onset sepsis, necrotising enterocolitis, intestinal perforation or both LOS and LOCNC were excluded.

EXPOSURES

LOS and LOCNC were defined as antibiotic administration for ≥5 days with and without a positive blood/cerebrospinal fluid culture, respectively. Infants with these diagnoses were also compared with infants with neither condition.

OUTCOMES

Death or NDI was assessed at 18-26 months corrected age follow-up. Modified Poisson regression models were used to estimate relative risks adjusting for covariates occurring ≤7 days of age.

RESULTS

Of 7354 eligible infants, 3940 met inclusion criteria: 786 (20%) with LOS, 1601 (41%) with LOCNC and 1553 (39%) with neither. Infants with LOS had higher adjusted relative risk (95% CI) for death/NDI (1.14 (1.05 to 1.25)) and death before follow-up (1.71 (1.44 to 2.03)) than those with LOCNC. Among survivors, risk for NDI did not differ between the two groups (0.99 (0.86 to 1.13)) but was higher for LOCNC infants (1.17 (1.04 to 1.31)) compared with unaffected infants.

CONCLUSIONS

Infants with LOS had higher risk of death, but not NDI, compared with infants with LOCNC. Surviving infants with LOCNC had higher risk of NDI compared with unaffected infants. Improving outcomes for infants with LOCNC requires study of the underlying conditions and the potential impact of antibiotic exposure.

Clinical Utility of Molecular Tests for Guiding Therapeutic Decisions in Bloodstream Staphylococcal Infections: A Meta-Analysis

Background: Treatment of bloodstream staphylococcal infections (BSI) necessitates the prompt initiation of appropriate antimicrobial agents and the rapid de-escalation of excessive broad-spectrum coverage to reduce the risk of mortality. We, therefore, aimed to demonstrate the diagnostic accuracy of nucleic acid amplification tests (NAAT) for the identification of methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) in clinically suspected patients. Methods: Until November 23, 2020, databases including PubMed, Scopus, Embase, and Web of Science were scanned for eligible studies. A bivariate random-effects model was used for meta-analysis of the 33 included studies obtained from 1606 citations, and pooled summary estimates with 95% confidence intervals (CI) were generated. Results: Twenty-three studies (n = 8,547) assessed NAAT accuracy for MSSA detection, while three studies (n = 479) evaluated MRSA detection in adults. The pooled NAAT sensitivity and specificity for MRSA in adults was higher [sensitivity: 0.83 (95% CI 0.59-0.96), specificity: 0.99 (95% CI 0.98-1.0)] as compared to MSSA [sensitivity: 0.76 (95% CI 0.69-0.82), specificity: 0.98 (95% CI 0.98-0.99)]. Similarly, eight studies (n = 4,089) investigating MSSA in pediatric population reported higher NAAT accuracy [sensitivity: 0.89 (95% CI 0.76-0.96), specificity: 0.98 (95% CI 0.97-0.98)] compared to adults. Among NAA tests, SeptiFast (real-time PCR, commercial) was frequently applied, and its diagnostic accuracy corresponded well to the overall summary estimates. A meta-regression and subgroup analysis of study design, sample condition, and patient selection method could not explain the heterogeneity (P > 0.05) in the diagnostic efficiency. Conclusions: NAAT could be applied as the preferred initial tests for timely diagnosis and BSI management.

Problem-solving in clinical practice: Persisting respiratory distress in a premature infant

The deterioration of a previously stable preterm infant is a common scenario on the neonatal unit. The the most common bacterial causes of deterioration are nosocomial infections, such as coagulase-negative Staphylococcus and Staphylococcus aureus Non-infective conditions such as pulmonary haemorrhage, anaemia of prematurity and necrotising enterocolitis may also cause preterm infants to deteriorate. This case chronicles the unusual diagnostic journey of an infant born at 27+1 weeks who deteriorated at 26 days of life and did not respond to antimicrobial therapy as anticipated.

How to interpret a paediatric blood culture

Blood culture is one of the most important diagnostic tests in medicine, considering the significant morbidity and mortality associated with bloodstream infection (BSI). However, it is an often misused and misinterpreted test in everyday paediatric practice. In this article, we explore the evidence related to paediatric blood cultures, with the aim of providing clear and clinically-relevant recommendations for its judicious use.