Procession to pediatric bacteremia and sepsis: covert operations and failures in diplomacy

HMGB1 mediates acute liver injury in sepsis through pyroptosis of liver macrophages

Sepsis is a systemic inflammatory response syndrome caused by infection. Septic patients often show an acute liver dysfunction during the onset of sepsis in ICU. We found the levels of ALT, AST, TBIL increased significantly in septic patients and returned after recovery from sepsis in our ICU (P<0.05), and had a similar trend for HMGB1. To explore the role of hepatic macrophage in acute liver injury, we simulated the process of acute liver injury by cecal ligation and puncture (CLP) in mice. We assessed the inflammatory infiltration of the liver by HE, and examined the levels of ALT and AST in serum and the expression of HMGB1, IL-1β in the serum and the relative expression of mRNA in the liver at the different time of CLP model. Also we found the rate of pyroptosis cells in liver was about 18.19%, while 16.29% in macrophages by Flow cytometry. So our study has demonstrated that HMGB1 may promote the pyroptosis of liver macrophages to mediate acute liver injury in sepsis.

Cytokine Levels in Critically Ill Children With Severe Sepsis and Their Relation With the Severity of Illness and Mortality

OBJECTIVE

To study the baseline cytokine levels and their relation with the severity of illness and mortality in critically ill children with severe sepsis.

DESIGN

Subgroup analysis of a randomized, double-blind, placebo-controlled trial.

SETTING

Pediatric intensive care unit of a tertiary level teaching hospital in India.

PATIENTS

Fifty children with severe sepsis aged 3 months to 12 years.

MATERIAL AND METHODS

Blood was collected at admission for estimation of pro-inflammatory (interleukin 6 [IL-6], IL-12p70, IL-17, and tumor necrotic factor α [TNF-α]) and anti-inflammatory (IL-10 and transforming growth factor β1 [TGF-β1]) cytokines.

PRIMARY OUTCOME

To find out correlation between cytokine levels and severity of illness scores (Pediatric Risk of Mortality [PRISM] III score, Sequential Organ Failure Assessment [SOFA], and Vasoactive-Inotropic Score [VIS]).

SECONDARY OUTCOMES

To compare cytokine levels among survivors and nonsurvivors.

RESULTS

Baseline pro-inflammatory cytokine levels (median [interquartile range]) were IL-6: 189 (35-285) pg/mL, IL-12p: 48 (28-98) pg/mL, IL-17: 240 (133-345) pg/mL, and TNF-α: 296 (198-430) pg/mL; anti-inflammatory cytokine levels were IL-10: 185 (62-395) pg/mL and TGF-β1: 204 (92-290) ng/mL. Pro-inflammatory cytokines showed positive correlation with PRISM III score: IL-6 (Spearman correlation coefficient, ρ = 0.273, P = .06), IL-12 (ρ = 0.367, P = .01), IL-17 (ρ = 0.197, P = .17), and TNF-α (ρ = 0.284, P = .05), and anti-inflammatory cytokines showed negative correlation: IL-10 (ρ = -0.257, P = .09) and TGF-β (ρ = -0.238, P = .11). Both SOFA and VIS also showed weak positive correlation with IL-12 (ρ = 0.32, P = .03 and ρ = 0.31, P = .03, respectively). Among nonsurvivors (n = 5), the levels of all the measured pro-inflammatory cytokines were significantly higher as compared to survivors, IL-6: 359 (251-499) pg/mL versus 157 (97-223) pg/mL, P < .0001, IL-12p70: 167 (133-196) pg/mL versus 66 (30-100) pg/mL, P < .0001, IL-17: 400 (333-563) pg/mL versus 237 (122-318) pg/mL, P = .009, and TNF-α: 409 (355-503) pg/mL versus 330 (198-415) pg/mL, P = .002, respectively.

CONCLUSION

In critically ill children with severe sepsis, pro-inflammatory cytokines (especially IL-12p70) showed a weak positive correlation with severity of illness and were significantly higher among nonsurvivors.

The Prognostic Value of Mannose-Binding Lectin in Community-Acquired Pneumonia

Introduction: Community-acquired pneumonia is among the most widespread health issues in the pediatric population, affecting children around the world. Mannose-binding lectin is a component of the innate immune system that binds to carbohydrate fragments expressed by various microorganisms, thus aiding in their recognition and eventually activating the complement system through a specific pathway called "the lectin pathway". Materials and methods: 204 pediatric patients whose mannose-binding lectin levels were evaluated at the beginning of infection were included in the study. Results: Mannose-binding lectin deficit was observed Conclusion: This study makes use of the relevant literature and tackles somewhat controversial aspects, as mannose-binding lectin deficit is classified as a fairly common disturbance of the immune system. For a comprehensive understanding of mannose-binding lectin role in infectious diseases, it is necessary to take into account even contextual factors.

Measuring vital signs in children with fever at the emergency department: an observational study on adherence to the NICE recommendations in Europe

Vital signs can help clinicians identify children at risk of serious illness. The NICE guideline for fever in under-fives recommends a routine measurement of temperature, heart rate, capillary refill and respiratory rate in all febrile children visiting the emergency department (ED). This study aims to evaluate the measurement of paediatric vital signs in European EDs, with specific attention to adherence to this NICE guideline recommendation. In a prospective observational study, we included 4560 febrile children under 16 years from the ED of 28 hospitals in 11 European countries (2014-2016). Hospitals were academic (n = 17), teaching (n = 10) and non-teaching (n = 1) and ranged in annual paediatric ED visits from 2700 to 88,000. Fifty-four percent were male, their median age was 2.4 years (IQR 1.1-4.7). Temperature was measured most frequently (97%), followed by capillary refill (86%), heart rate (73%), saturation (56%) and respiratory rate (51%). In children under five (n = 3505), a complete measurement of the four NICE-recommended vital signs was performed in 48% of patients. Children under 1 year of age, those with an urgent triage level and with respiratory infections had a higher likelihood of undergoing complete measurements. After adjustment for these factors, variability between countries remained. Conclusion: Measuring vital signs in children with fever in the ED occurs with a high degree of practice variation between different European hospitals, and adherence to the NICE recommendation is moderate. Our study is essential as a benchmark for current clinical practice, in order to tailor implementation strategies to different European settings.What is Known:• Vital signs can quickly provide information on disease severity in children in the emergency department (ED), and the NICE guideline for fever in under-fives recommends to routinely measure temperature, heart rate, capillary refill and respiratory rate.• Data regarding measurement of vital signs in routine practice across European EDs is currently unavailable.What is New:• Measurement of vital signs in febrile children is highly variable across European EDs and across patient subgroups, and compliance to the NICE recommendation is <50%.• Children under 1 year of age, those with an urgent triage level and with respiratory infections had a higher likelihood of undergoing complete measurements.

The correct blood volume for paediatric blood cultures: a conundrum?

BACKGROUND

Bloodstream infections (BSIs) are a major cause of morbidity and mortality in paediatric patients. For fast and accurate diagnosis, blood culture (BC) is the reference standard. However, the procedure for blood sampling in paediatric patients, particularly the optimal blood volume, is the subject of controversy stemming from a lack of knowledge of the bacterial load and because of several obstacles such as low intravascular volume and the risk of causing anaemia.

AIMS

The aim of this narrative review is to summarize current knowledge on blood sampling in paediatric patients for BC purposes, in particular blood volume and number and type of BC bottles needed for reasonable future guidelines/recommendations.

SOURCES

A comprehensive literature search of PubMed, including all publications in English, was performed in June 2019 using the search terms 'blood culture', 'blood volume', 'bloodstream infection', 'diagnostic', 'paediatric' and/or 'sepsis'.

CONTENT

The amount of inoculated blood determines the sensitivity, specificity and time to positivity of a BC, and low-level bacteraemia (≤10 cfu/mL) in paediatric patients is presumed to be more common than reported. Current approaches for 'adequate' blood volume for paediatric BC are mainly weight- or age-dependent. Of these recommendations, the scheme devised by Gaur and colleagues seems most appropriate and calls for a sample of 1-1.5 mL for children weighing <11 kg and 7.5 mL for a patient weight of 11-17 kg to be drawn into one BC bottle. Inclusion of a more detailed grading in the weight range 4-14 kg, as published by Gonsalves and colleagues, might be useful.

IMPLICATIONS

This review could be important for future guidelines on paediatric BC collection and thus could contribute to improving patient management and lowering the economic and global health burden associated with BSI. Furthermore, upcoming molecular-based approaches with low sample volumes might be an interesting alternative.

Direct detection of bacteremia by exploiting host-pathogen interactions of lipoteichoic acid and lipopolysaccharide

Bacteremia is a leading cause of death in sub-Saharan Africa where childhood mortality rates are the highest in the world. The early diagnosis of bacteremia and initiation of treatment saves lives, especially in high-disease burden areas. However, diagnosing bacteremia is challenging for clinicians, especially in children presenting with co-infections such as malaria and HIV. There is an urgent need for a rapid method for detecting bacteremia in pediatric patients with co-morbidities to inform treatment. In this manuscript, we have developed and clinically validated a novel method for the direct detection of amphiphilic pathogen biomarkers indicative of bacteremia, directly in aqueous blood, by mimicking innate immune recognition. Specifically, we have exploited the interaction of amphiphilic pathogen biomarkers such as lipopolysaccharides (LPS) from Gram-negative bacteria and lipoteichoic acids (LTA) from Gram-positive bacteria with host lipoprotein carriers in blood, in order to develop two tailored assays – lipoprotein capture and membrane insertion – for their direct detection. Our assays demonstrate a sensitivity of detection of 4 ng/mL for LPS and 2 ng/mL for LTA using a waveguide-based optical biosensor platform that was developed at LANL. In this manuscript, we also demonstrate the application of these methods for the detection of LPS in serum from pediatric patients with invasive Salmonella Typhimurium bacteremia (n = 7) and those with Staphylococcal bacteremia (n = 7) with 100% correlation with confirmatory culture. Taken together, these results demonstrate the significance of biochemistry in both our understanding of host-pathogen biology, and development of assay methodology, as well as demonstrate a potential new approach for the rapid, sensitive and accurate diagnosis of bacteremia at the point of need.

Precision Medicine for Neonatal Sepsis

Neonatal sepsis remains a significant cause of morbidity and mortality especially in the preterm infant population. The ability to promptly and accurately diagnose neonatal sepsis based on clinical evaluation and laboratory blood tests remains challenging. Advances in high-throughput molecular technologies have increased investigations into the utility of transcriptomic, proteomic and metabolomic approaches as diagnostic tools for neonatal sepsis. A systems-level understanding of neonatal sepsis, obtained by using omics-based technologies (at the transcriptome, proteome or metabolome level), may lead to new diagnostic tools for neonatal sepsis. In particular, recent omic-based studies have identified distinct transcriptional signatures and metabolic or proteomic biomarkers associated with sepsis. Despite the emerging need for a systems biology approach, future studies have to address the challenges of integrating multi-omic data with laboratory and clinical meta-data in order to translate outcomes into precision medicine for neonatal sepsis. Omics-based analytical approaches may advance diagnostic tools for neonatal sepsis. More research is needed to validate the recent systems biology findings in order to integrate multi-dimensional data (clinical, laboratory and multi-omic) for future translation into precision medicine for neonatal sepsis. This review will discuss the possible applications of omics-based analyses for identification of new biomarkers and diagnostic signatures for neonatal sepsis, focusing on the immune-compromised preterm infant and considerations for clinical translation.

Blood Cultures Drawn From Arterial Catheters Are Reliable for the Detection of Bloodstream Infection in Critically Ill Children

OBJECTIVES

Arterial catheters may serve as an additional source for blood cultures in children when peripheral venipuncture is challenging. The aim of the study was to evaluate the accuracy of cultures obtained through indwelling arterial catheters for the diagnosis of bloodstream infections in critically ill pediatric patients.

DESIGN

Observational and comparative.

SETTING

General and cardiac ICUs of a tertiary, university-affiliated pediatric medical center.

PATIENTS

The study group consisted of 138 patients admitted to the general or cardiac PICU in 2014-2015 who met the following criteria: presence of an indwelling arterial catheter and indication for blood culture.

INTERVENTIONS

Blood was drawn by peripheral venipuncture and through the arterial catheter for each patient and sent for culture (total 276 culture pairs).

MEASUREMENTS AND MAIN RESULTS

Two specialists blinded to the blood source evaluated each positive culture to determine if the result represented true bloodstream infection or contamination. The sensitivity, specificity, and positive and negative predictive values of the arterial catheter and peripheral cultures for the diagnosis of bloodstream infection were calculated. Of the 56 positive cultures, 41 (15% of total samples) were considered diagnostic of true bloodstream infection. In the other 15 (5%), the results were attributed to contamination. The rate of false-positive results was higher for arterial catheter than for peripheral venipuncture cultures (4% vs 1.5%) but did not lead to prolonged unnecessary antibiotic treatment. On statistical analysis, arterial catheter blood cultures had high sensitivity (85%) and specificity (95%) for the diagnosis of true bloodstream infection, with comparable performance to peripheral blood cultures.

CONCLUSION

Cultures of arterial catheter-drawn blood are reliable for the detection of bloodstream infection in PICUs.

Translation of clinical prediction rules for febrile children to primary care practice: an observational cohort study

BACKGROUND

Clinical prediction rules (CPRs) to identify children with serious infections lack validation in low-prevalence populations, which hampers their implementation in primary care practice.

AIM

To evaluate the diagnostic value of published CPRs for febrile children in primary care.

DESIGN AND SETTING

Observational cohort study among febrile children (<16 years) who consulted five GP cooperatives (GPCs) in the Netherlands.

METHOD

Alarm signs of serious infection and clinical management were extracted from routine clinical practice data and manually recoded with a structured electronic data-entry program. Eight CPRs were selected from literature. CPR-variables were matched with alarm signs and CPRs were applied to the GPC-population. 'Referral to emergency department (ED)' was used as a proxy outcome measure for 'serious infection'. CPR performance was assessed by calibration analyses, sensitivity, specificity, and area under the ROC-curve (ROC-area).

RESULTS

A total of 9794 GPC-contacts were eligible, 54% male, median age 2.3 years (interquartile range 1.0-4.6 years) and 8.1% referred to ED. Frequencies of CPR-variables varied from 0.5% (cyanosis, drowsy) to 25% (temperature ≥40°C). Alarm signs frequently included in CPRs were 'ill appearance', 'inconsolable', and 'abnormal circulatory or respiratory signs'. The height of the CPR's predicted risks generally corresponded with being (or not being) referred to the ED in practice. However, calibration-slopes indicated that three CPRs underestimated the risk of serious infection in the GPC-population. Sensitivities ranged from 42% to 54%, specificities from 68% to 89%. ROC-areas ranged from 0.52 to 0.81, with best performance of CPRs for children aged <3 months.

CONCLUSION

Published CPRs performed moderately well in the primary out-of-hours care population. Advice is given on how to improve translation of CPRs to primary care practice.

Inflammatory Response in Preterm and Very Preterm Newborns with Sepsis

The response of the adaptive immune system is usually less intense in premature neonates than term neonates. The primary objective of this study was to determine whether immunological parameters vary between preterm (PT) neonates (≥32 weeks of gestational age) and very preterm (VPT) neonates (<32 weeks of gestational age). A cross-sectional study was designed to prospectively follow PT and VPT neonates at risk of developing sepsis. Plasma concentrations of IFN-γ, TNF-α, IL-6, IL-4, and IL-10 were detected using flow cytometry. C-reactive protein (C-RP) and the complex SC5b-9 were detected in the plasma using commercial kits. A total of 83 patients were included. The laboratory results and clinical histories showed that 26 patients had sepsis; 14 were VPT, and 12 were PT. The levels of C-RP, SC5b-9 (innate immune response mediators), and IL-10 or IL-4 (anti-inflammatory cytokines) were elevated during sepsis in both groups. IFN-γ, TNF-α, and IL-6 (proinflammatory cytokines) were differentially elevated only in PT neonates. The VPT neonates with sepsis presented increases in C-RP, SC5b-9, and anti-inflammatory cytokines but not in proinflammatory cytokines, whereas PT neonates showed increases in all studied mediators of inflammation.

Infection Risk Reduction in the Intensive Care Nursery: A Review of Patient Care Practices That Impact the Infection Risk in Global Care of the Hospitalized Neonates

Neonates are at high risk for developing an infection during their hospital stay in the neonatal intensive care unit. Increased risk occurs because of immaturity of the neonate's immune system, lower gestational age, severity of illness, surgical procedures, and instrumentation with life support devices such as vascular catheters. Neonates become colonized with bacteria prior to or at delivery and also during their hospital stay. They can then become infected with those bacteria if there is a breakdown in the primary defenses such as tissue injury due to skin breakdown, nasal erosion, or trauma to the respiratory tract. Neonates are also at high risk for bacterial translocation due to the altered permeability of the intestinal mucosa, loss of commensal flora, and bacterial overgrowth. The unit-based neonatal care team must implement global care delivery and safety practices, utilize published care guidelines, know and apply evidence-based practices from collaborative quality improvement efforts and other sources, and use auditing and monitoring practices that can identify risks and lead to better practice options to prevent infections. This article presents several aspects of global neonatal care delivery, including vascular access, which may reduce the risk of systemic infection during the hospitalization.

Diagnosis of Bloodstream Infections in Children

Identification of bloodstream infections is among the most critical tasks performed by the clinical microbiology laboratory. While the criteria for achieving an adequate blood culture specimen in adults have been well described, there is much more ambiguity in pediatric populations. This minireview focuses on the available pediatric literature pertaining to the collection of an optimal blood culture specimen, including timing, volume, and bottle selection, as well as rapid diagnostic approaches and their role in the management of pediatric bloodstream infections.

Bacteremia in Early Infancy: Etiology and Management

We reviewed the literature regarding bacteremia in early infancy (age ≤ 90 days). Bacteremia remains a major cause of morbidity and mortality in young infants. However, recent epidemiologic data suggest that the incidence of bacteremia is decreasing and the pathogens responsible for invasive disease are changing. These changes will impact the evaluation and management of young infants. We review the current epidemiology of community-acquired bacteremia in early infancy with particular emphasis on the causative agents, diagnostic evaluation, and empiric and definitive antimicrobial treatment.

[Blood cultures in the paediatric emergency department. Guidelines and recommendations on their indications, collection, processing and interpretation]

Blood culture (BC) is the gold standard when a bacteraemia is suspected, and is one of the most requested microbiological tests in paediatrics. Some changes have occurred in recent years: the introduction of new vaccines, the increasing number of patients with central vascular catheters, as well as the introduction of continuous monitoring BC systems. These changes have led to the review and update of different factors related to this technique in order to optimise its use. A practice guideline is presented with recommendations on BC, established by the Spanish Society of Paediatric Emergency Care and the Spanish Society for Paediatric Infectious Diseases. After reviewing the available scientific evidence, several recommendations for each of the following aspects are presented: BC indications in the Emergency Department, how to obtain, transport and process cultures, special situations (indications and interpretation of results in immunosuppressed patients and/or central vascular catheter carriers, indications for anaerobic BC), differentiation between bacteraemia and contamination when a BC shows bacterial growth and actions to take with a positive BC in patients with fever of unknown origin.

Translocation of gut flora and its role in sepsis

Bacterial translocation is the invasion of indigenous intestinal bacteria through the gut mucosa to normally sterile tissues and the internal organs. Sometimes instead of bacteria, inflammatory compounds are responsible for clinical symptoms as in systemic inflammatory response syndrome (SIRS). The difference between sepsis and SIRS is that pathogenic bacteria are isolated from patients with sepsis but not with those of SIRS. Bacterial translocation occurs more frequently in patients with intestinal obstruction and in immunocompromised patients and is the cause of subsequent sepsis. Factors that can trigger bacterial translocation from the gut are host immune deficiencies and immunosuppression, disturbances in normal ecological balance of gut, mucosal barrier permeability, obstructive jaundice, stress, etc. Bacterial translocation occurs through the transcellular and the paracellular pathways and can be measured both directly by culture of mesenteric lymph nodes and indirectly by using labeled bacteria, peripheral blood culture, detection of microbial DNA or endotoxin and urinary excretion of non-metabolisable sugars. Bacterial translocation may be a normal phenomenon occurring on frequent basis in healthy individuals without any deleterious consequences. But when the immune system is challenged extensively, it breaks down and results in septic complications at different sites away from the main focus. The factors released from the gut and carried in the mesenteric lymphatics but not in the portal blood are enough to cause multi-organ failure. Thus, bacterial translocation may be a promoter of sepsis but not the initiator. This paper reviews literature on the translocation of gut flora and its role in causing sepsis.

Prevalence, clinical features, and outcome of pseudomonas bacteremia in under-five diarrheal children in bangladesh

We sought to evaluate the prevalence, associated factors, and outcome of under-five diarrheal children with either sex having Pseudomonas bacteremia. A retrospective chart review of under-five diarrheal children admitted to the Dhaka Hospital of the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), from January 2011 to December 2011 was performed using an online hospital management system. Children with Pseudomonas bacteremia constituted the cases (n = 31), and the controls (n = 124), without Pseudomonas bacteremia, were randomly selected. The prevalence of Pseudomonas bacteremia was 1% (31/5,179). The Pseudomonas was multidrug resistant but was 84% sensitive to ceftazidime and 100% to imipenem. The case-fatality rate was significantly higher among the cases than the controls (26% versus 5%; P = 0.003). In logistic regression analysis, after adjusting for potential confounders such as severe wasting, severe underweight, severe pneumonia, and young age (11.71 (4.0, 18.0) months), the cases more often presented with absent peripheral pulses in absence of dehydration (95% CI = 2.31–24.45) on admission. This finding underscores the importance of early identification of this simple clinical sign to ensure prompt management including fluid resuscitation and broad spectrum antibiotics to help reduce morbidity and mortality in such children, especially in resource-poor settings.

Urinary (1)H-NMR and GC-MS metabolomics predicts early and late onset neonatal sepsis

The purpose of this article is to study one of the most significant causes of neonatal morbidity and mortality: neonatal sepsis. This pathology is due to a bacterial or fungal infection acquired during the perinatal period. Neonatal sepsis has been categorized into two groups: early onset if it occurs within 3-6 days and late onset after 4-7 days. Due to the not-specific clinical signs, along with the inaccuracy of available biomarkers, the diagnosis is still a major challenge. In this regard, the use of a combined approach based on both nuclear magnetic resonance ((1)H-NMR) and gas-chromatography-mass spectrometry (GC-MS) techniques, coupled with a multivariate statistical analysis, may help to uncover features of the disease that are still hidden. The objective of our study was to evaluate the capability of the metabolomics approach to identify a potential metabolic profile related to the neonatal septic condition. The study population included 25 neonates (15 males and 10 females): 9 (6 males and 3 females) patients had a diagnosis of sepsis and 16 were healthy controls (9 males and 7 females). This study showed a unique metabolic profile of the patients affected by sepsis compared to non-affected ones with a statistically significant difference between the two groups (p = 0.05).

Sepsis

Hyperthermie (>38,5 °C) oder Hypothermie (<36,0 °C)

Tachykardie (Herzfrequenz >2SD über der altersentsprechenden Norm) oder Bradykardie (Herzfrequenz <10. Perzentile) im Alter <1 Jahr

Tachypnoe (Atemfrequenz >2SD über der altersentsprechenden Norm)

Leukozytose oder Leukozytopenie oder Linksverschiebung (>10 % unreife Neutrophile),

Nachweis oder Verdacht auf eine Infektion

Use of alarm features in referral of febrile children to the emergency department: an observational study

BACKGROUND

The diagnostic value of alarm features of serious infections in low prevalence settings is unclear.

AIM

To explore to what extent alarm features play a role in referral to the emergency department (ED) by GPs who face a febrile child during out-of-hours care.

DESIGN AND SETTING

Observational study using semi-structured, routine clinical practice data of febrile children (<16 years) presenting to GP out-of-hours care.

METHOD

Logistic regression analyses were performed to assess the association between alarm features of serious infections (selected from two guidelines and one systematic review) and referral to the ED. Adherence to the guideline was explored by a 2×2 contingency table.

RESULTS

In total 794 (8.1%) of 9794 eligible patients were referred to the ED. Alarm signs most strongly associated with referral were 'age <1 month', 'decreased consciousness', 'meningeal irritation', and 'signs of dehydration'. Nineteen percent of 3424 children with a positive referral indication according to the guideline were referred to the ED. The majority of those not referred had only one or two alarm features present. A negative referral indication was adhered to for the majority of children. Still, in 20% of referred children, alarm features were absent.

CONCLUSION

In contrast to guidance, GPs working in primary out-of-hours care seem more conservative in referring febrile children to the ED, especially if only one or two alarm features of serious infection are present. In addition, in 20% of referred children, alarm features were absent, which suggests that other factors may be important in decisions about referral of febrile children to the hospital ED.

Group B streptococci in milk and late neonatal infections: an analysis of cases in the literature

BACKGROUND

The source for late-onset neonatal infections (LONI) due to group B Streptococcus (GBS) has not been fully explored. We reviewed GBS LONI cases associated with contaminated breast milk to determine whether breast milk was a possible route for neonatal infection.

DATA SOURCES

A PubMed search from January 1977 to March 2013 was performed with MeSH words "Streptococcus agalactiae", "group B Streptococcus", "infection", "milk", "human", "late-onset infection" and/or "neonate"; relevant cross references were also reviewed.

RESULTS

Forty-eight documented cases of GBS LONI matched our search criteria and were retrieved from the literature. When performed, molecular typing identified clonal isolates in the neonate and milk samples taken after LONI in all cases, with the hypervirulent sequence type 17 (ST-17) clone identified in two of these cases. Caesarean delivery combined with the absence of GBS recovery from maternal samples other than milk was noted for four cases. The rate of recurrent infections was high (35%) and, together with the data reviewed, points to a potential role of breast milk in GBS LONI.

CONCLUSIONS

The cases reviewed here, together with the evidence of breast milk transmission for other pathogens, suggest that breast milk, which would account for repeated GBS transmission to the neonate, may favour gut translocation and subsequent LONI. Further investigations are nevertheless needed to study the relative importance of this contamination route compared with persistent postnatal gut colonisation and the dynamics of milk and neonatal gut colonisation.

Pediatric bloodstream infections in Cambodia, 2007 to 2011

BACKGROUND

Pediatric bacterial bloodstream infections (BSIs) are a major cause of morbidity and mortality worldwide. Epidemiological data from resource-limited settings in southeast Asia, such as Cambodia, are sparse but have important implications for treatment and public health strategies.

METHODS

We retrospectively investigated BSI in children at a pediatric hospital and its satellite clinic in Siem Reap, Cambodia, from January 1, 2007, to July 31, 2011. The range of bacterial pathogens and their antimicrobial susceptibility patterns were analyzed in conjunction with demographic, clinical and outcome data.

RESULTS

Of 7682 blood cultures with results (99.9% of cultures taken), 606 (7.9%) episodes of BSI were identified in 588 children. The incidence of BSI increased from 14 to 50/1000 admissions (P < 0.001); this was associated with an increased sampling rate. Most BSI were community acquired (89.1%). Common pathogens included Salmonella Typhi (22.8% of all isolates), Staphylococcus aureus (12.2%), Streptococcus pneumoniae (10.0%), Klebsiella pneumoniae (6.4%) and Escherichia coli (6.3%). 21.5% of BSI were caused by a diverse group of uncommon organisms, the majority of which were environmental Gram-negative species. No Listeria monocytogenes or Group B streptococcal BSI were identified. Antimicrobial resistance, particularly among the Enterobacteriaceae, was common. Overall mortality was substantial (19.0%), higher in neonates (36.9%) and independently associated with meningitis/meningoencephalitis and K. pneumoniae infection.

CONCLUSIONS

BSI is a common problem in Cambodian children attending hospital and associated with significant mortality. Further studies are needed to clarify the epidemiology of neonatal sepsis, the contribution of atypical organisms and the epidemiology of pneumococcal disease before the introduction of vaccine.

Role of the central venous catheter in bloodstream infections caused by coagulase-negative staphylococci in very preterm neonates

BACKGROUND

Pathogenesis of coagulase-negative staphylococcal bloodstream infections among preterm neonates is debated: central venous catheters (CVCs) are considered the major cause and the cornerstone of prevention measures. The role of other means of transmission is unknown.

METHODS

We developed a specific quantitative polymerase chain reaction assay targeting the dnaJ gene from Staphylococcus epidermidis and Staphylococcus capitis to detect DNA from CVC used in preterms. Performance of the polymerase chain reaction was tested against 2 control groups of CVC yielding positive (n = 24) or negative (n = 63) conventional cultures. We also explored retrospectively the DNA load of CVC having a negative conventional bacterial culture and obtained from 34 very preterm neonates with catheter-related bloodstream infections (CR-BSIs) established by usual clinical and biologic criteria.

RESULTS

The molecular approach allowed detection of corresponding DNA from all the positive control catheters. Among the 34 episodes of CR-BSI yielding a negative conventional CVC culture, 8 (23.5%) had a positive polymerase chain reaction signal (5 S. epidermidis and 3 S. capitis). This percentage did not significantly differ according to the staphylococcal species, the delay between the CVC insertion and the beginning of the sepsis or between the blood culture collection and the CVC removal. These results conform to the previously published 70% of CR-BSI for whom the origin could be questioned.

CONCLUSIONS

CVC removal in preterms is often performed in cases of CR-BSI; our study supports the hypothesis that in some cases the responsibility of CVC is questionable.

Alarming signs in the Manchester triage system: a tool to identify febrile children at risk of hospitalization

OBJECTIVES

To assess whether the flowcharts and discriminators of the Manchester Triage System (MTS) can be used as indicators of alarming signs of serious febrile illness to predict the risk of hospitalization for febrile children who present at the emergency department (ED).

STUDY DESIGN

Observational study, which included 2455 children (<16 years) who came to the ED of a university hospital with fever as their main complaint (May 2007-July 2009). Alarming signs for serious febrile illness were matched with MTS flowcharts and discriminators. At triage, the percentage of alarming signs positive was calculated. The diagnostic ability of the percentage of alarming signs positive to identify children at risk of hospitalization was assessed by calculating positive and negative likelihood ratios.

RESULTS

Thirty percent of children had at least 1 alarming sign positive at triage. Twenty-three percent were hospitalized. Positive likelihood ratios of hospitalization were 5.0 (95% CI: 3.9-6.5) for children with >20% of alarming signs positive at triage and 12.0 (95% CI: 5.2-27.6) for those with >40% of alarming signs positive. Negative likelihood ratios were 0.8 (95% CI: 0.8-0.8) and 1.0 (95% CI: 0.9-1.0), respectively.

CONCLUSIONS

By alternatively using the flowcharts and discriminators of the MTS as alarming signs, rather than urgency classifiers, the MTS can function as a simple, readily available tool to identify febrile children at risk of hospitalization early in the care process. This knowledge may help to improve ED throughput times as well as admission and discharge management at pediatric EDs.

Influence of bacteriophage preparations on intracellular killing of bacteria by human phagocytes in vitro

Bacteriophages are viruses that infect bacteria. It was shown that bacteriophage therapy is an effective method of combating bacterial infections, including infections caused by antibiotic-resistant bacterial strains. One of the main obstacles to widespread use of phage preparations is limited knowledge regarding the influence of bacteriophages on human organisms. In our study, we evaluated whether application of phage preparations impair bactericidal activities of human phagocytes (granulocytes and monocytes). In our study, we used preparations of phages T2 and T4 specific to Escherichia coli and A3 phage specific to Staphylococcus aureus. We found that bacteriophage preparations do not influence intracellular killing of bacteria by human phagocytes. The effect is irrespective of phage preparation type (lysate, purified phage preparation), phage titer of the preparation, and whether bacteria phagocytosed by phagocyte cells are sensitive or insensitive to phage (bacteriophages homologous and heterologous to bacteria). Although the results of our study are preliminary, they support previous data indicating safety of therapeutic application of phages.

[Dermohypodermitis and gut translocation Escherichia coli septicemia in a newborn infant]

The burden of neonatal bacterial infections continues. They remain a significant cause of death and morbidity, despite recommendations for prevention. The epidemiology of these infections has changed. Currently the two most causative pathogens for early-onset neonatal sepsis and for late-onset sepsis in term infants are Group B streptococci (GBS) and Escherichia coli. E. coli's role is increasingly important since the widespread use of intrapartum antibiotic prophylaxis. In late-onset infections, one of the suggested pathophysiological mechanisms is microbial translocation in the gut secondary to digestive colonization, particularly when E. coli is isolated in blood cultures. This can occur either before or after birth. Bacterial sepsis can be associated with various non-specific peripheral manifestations involving skin and soft tissues. We report the case of a full-term, 26-day-old newborn admitted to the hospital for fever. She presented with dermohypodermitis of the left trunk and was diagnosed with E. coli septicemia. She was discharged in good condition after appropriate intravenous antibiotic therapy.

Ampicillin and gentamicin are a useful first-line combination for the management of sepsis in under-five children at an urban hospital in Bangladesh

The study evaluated the commonly-used drugs for the management of sepsis and their outcome among under-five children. We evaluated the hospital-records of all paediatric sepsis patients (n = 183) in the intensive care unit (ICU) and longer-stay unit (LSU) of the Dhaka Hospital of icddr,b. These records were collected from the hospital management system (SHEBA) during November 2009 to October 2010. A total of 183 under-five children with clinical sepsis were found during the study period, and 14 (8%) of them were neonates. One hundred and eighty-one patients had received a combination of injection ampicilin and injection gentamicin, and two patients had received the combination of injection ceftriaxone and injection gentamicin. Only 46 (25%) patients required a change of antibiotics to the combination of intravenous ceftriaxone plus gentamicin after non-response of injection ampicilin and injection gentamicin combination; 7/181 (4%) patients died who received injection ampicilin and injection gentamicin whereas none died among the other two patients who received injection ceftriaxone and injection gentamicin (p = 1.00). The combination of injection ampicilin and injection gentamicin as the first-line antibiotics for the management of sepsis in children even beyond the neonatal age is very effective, resulting in lower mortality.

Community faecal carriage of extended-spectrum beta-lactamase-producing Enterobacteriaceae in French children

Background

The increasing incidence of community acquired infection due to Extended-Spectrum Beta-Lactamase (ESBL) -Producing Enterobacteriaceae represent a great concern because there are few therapeutic alternatives. The fecal flora of children in the community can represent a reservoir for ESBLs genes which are located on highly transmissible plasmids and the spread of these genes among bacterial pathogens is concerning. Because intestinal carriage is a key factor in the epidemiology of ESBL-producing Enterobacteriaceae, the study of the prevalence of these resistant bacteria and risk factors in young children is of particular interest.

Methods

We assessed the prevalence and risk factors of community-acquired faecal carriage of extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae in children aged from 6 to 24 months, by means of rectal swabbing in community pediatric practices. Child’s lifestyle and risk factors for carriage of resistant bacteria were noted.

Results

Among the 411 children enrolled, 4.6% carried ESBL-producing Enterobacteriaceae. CTX-M-1, CTX-M-15 and CTX-M-14 were the predominant ESBLs. The 18 E. coli isolates were genetically heterogeneous. Recent third-generation oral-cephalosporin exposure was associated with a higher risk of ESBL carriage (AOR=3.52, 95% CI[1.06-11.66], p=0.04).

Conclusions

The carriage rate of ESBL-producing Enterobacteriacae in young children in the French community setting is noteworthy, underlining the importance of this population as a reservoir. Exposure to third-generation oral cephalosporins was associated with a significant risk of ESBL carriage in our study. Because of the significant public health implications including the treatment of community-acquired urinary tract infections, the spread of organisms producing ESBLs in the community merits close monitoring with enhanced efforts for surveillance.

Gut microbial translocation in critically ill children and effects of supplementation with pre- and pro biotics

Bacterial translocation as a direct cause of sepsis is an attractive hypothesis that presupposes that in specific situations bacteria cross the intestinal barrier, enter the systemic circulation, and cause a systemic inflammatory response syndrome. Critically ill children are at increased risk for bacterial translocation, particularly in the early postnatal age. Predisposing factors include intestinal obstruction, obstructive jaundice, intra-abdominal hypertension, intestinal ischemia/reperfusion injury and secondary ileus, and immaturity of the intestinal barrier per se. Despite good evidence from experimental studies to support the theory of bacterial translocation as a cause of sepsis, there is little evidence in human studies to confirm that translocation is directly correlated to bloodstream infections in critically ill children. This paper provides an overview of the gut microflora and its significance, a focus on the mechanisms employed by bacteria to gain access to the systemic circulation, and how critical illness creates a hostile environment in the gut and alters the microflora favoring the growth of pathogens that promote bacterial translocation. It also covers treatment with pre- and pro biotics during critical illness to restore the balance of microbial communities in a beneficial way with positive effects on intestinal permeability and bacterial translocation.

Self-referral and serious illness in children with fever

OBJECTIVE

The goal of this study was to evaluate parents' capability to assess their febrile child's severity of illness and decision to present to the emergency department. We compared children referred by a general practitioner (GP) with those self-referred on the basis of illness-severity markers.

METHODS

This was a cross-sectional observational study conducted at the emergency departments of a university and a teaching hospital. GP-referred or self-referred children with fever (aged <16 years) who presented to the emergency department (2006-2008) were included. Markers for severity of illness were urgency according to the Manchester Triage System, diagnostic interventions, therapeutic interventions, and follow-up. Associations between markers and referral type were assessed by using logistic regression analysis. Subgroup analyses were performed for patients with the most common presenting problems that accompanied the fever (ie, dyspnea, gastrointestinal complaints, neurologic symptoms, fever without specific symptoms).

RESULTS

Thirty-eight percent of 4609 children were referred by their GP and 62% were self-referred. GP-referred children were classified as high urgency (immediate/very urgent categories) in 46% of the cases and self-referrals in 45%. Forty-three percent of GP referrals versus 27% of self-referrals needed extensive diagnostic intervention, intravenous medication/aerosol treatment, hospitalization, or a combination of these (odds ratio: 2.0 [95% confidence interval: 1.75-2.27]). In all subgroups, high urgency was not associated with referral type. GP-referred and self-referred children with dyspnea had similar frequencies of illness-severity markers.

CONCLUSIONS

Although febrile self-referred children were less severely ill than GP-referred children, many parents properly judged and acted on the severity of their child's illness. To avoid delayed or missed diagnoses, recommendations regarding interventions that would discourage self-referral to the emergency department should be reconsidered.

An unusual presentation of a congenital intrahepatic arterioportal fistula in an infant with Down syndrome

Congenital intrahepatic arterioportal fistula is a rare entity that most often presents with symptoms of portal hypertension and malabsorption. We discuss a patient who presented with distributive shock, congestive heart failure, pulmonary hypertension, ascites, and a history of severe constipation.