An epidemic of meningococcal disease in children in North Norway in the 1970s and 1980s was dominated by a hypervirulent group B strain.

AIM: We examined children hospitalised for invasive meningococcal disease, a leading cause of paediatric sepsis, in Troms County, North Norway, from 1973 to 2016, including the epidemic in the 1970s and 1980s. METHODS: This study was a retrospective review of children under the age of 15 years who were hospitalised for meningococcal disease at the University Hospital of North Norway and Harstad Hospital. We studied hospital and bacteriological records to determine the incidence rates and phenotypes involved. RESULTS: There were 300 cases under 15 years and an incidence rate of 17 per 100,000 cases for 1973-2016. This was broken down into the following: 1973-1980 (n = 130, 49), 1981-1990 (n = 129, 39), and 1991-2016 (n = 41, 4.7), respectively. There were 21 (7%) deaths. Phenotype B:15:P1.7,16 was more common than the other phenotypes in the epidemic period before 1990 than after 1990 (p = 0.02) and had a significantly lower mortality rate than the other phenotypes (p = 0.04). Later years showed a more heterogenous phenotype distribution. Serogroup B was the dominant serogroup. CONCLUSION: The B:15:P1.7,6 strain was more prevalent during the Norwegian epidemic of invasive meningococcal disease, but had a significantly lower mortality rate. The phenotype distribution was more heterogeneous after 1990. The dominant serogroup was B.

Arterial versus venous lactate: a measure of sepsis in children.

This study assessed the agreement between arterial and venous blood lactate and pH levels in children with sepsis. This retrospective, three-year study involved 60 PICU patients, with data collected from electronic or paper patient records. The inclusion criteria comprised of children (≤17 years old) with sepsis and those who had a venous blood gas taken first with an arterial blood gas taken after within one hour. The lactate and pH values measured through each method were analysed. There is close agreement between venous and arterial lactate up to 2 mmol/L. As this value increases, this agreement becomes poor. The limits of agreement (LOA) are too large (±1.90 mmol/L) to allow venous and arterial lactate to be used interchangeably. The mean difference and LOA between both methods would be much smaller if derived using lactate values under 2.0 mmol/L. There is close agreement between arterial and venous pH (MD = -0.056, LOA ± 0.121). However, due to extreme variations in pH readings during sepsis, pH alone is an inadequate marker. CONCLUSION: A venous lactate ≤2 mmol/L can be used as a surrogate for arterial lactate during early management of sepsis in children. However, if the value exceeds 2 mmol/L, an arterial sample must confirm the venous result. What is known: • In children with septic shock, a blood gas is an important test to show the presence of acidosis and high lactic acid. Hyperlactataemia on admission is an early predictor of outcome and is associated with a greater mortality risk. • An arterial sample is the standard for lactate measurement, however getting a sample may be challenging in the emergency department or a general paediatric ward. Venous samples are quicker and easier to obtain. Adult studies generally advise caution in replacing venous lactate values for the arterial standard, whilst paediatric studies are limited in this area. What is new: • This is the first study assessing the agreement between arterial and peripheral venous lactate in children with sepsis, with a significant sample of patients. • This study shows that a venous sample with a lactate of ≤ 2 mmol/L can be used as a surrogate measurement for arterial lactate during early management of sepsis in children. However, if the venous lactate is above 2 mmol/L, an arterial sample must be taken to confirm the result.

Is the developmentally immature immune response in paediatric sepsis a recapitulation of immune tolerance?

Immunologically immature neonates suffer the highest incidence of paediatric sepsis. Postnatal immunological maturation is characterized by a relatively hypo-inflammatory immune response. The mechanisms that differentiate the mature and immature immune responses resemble those that differentiate the hyper- and hypo-inflammatory responses in severe sepsis. Immunological maturational differences likely affect the neonate's ability to mount an appropriate hyper-inflammatory response, a counteractive hypo-inflammatory response, and subsequent return to immune system homeostasis. To better understand the role of the hypo-inflammatory response in paediatric sepsis, we will explore the maturation of the immune system and the effect it may have on the sepsis-induced hypo-inflammatory response.

Paediatric sepsis survivors are resistant to sepsis-induced long-term immune dysfunction.

BACKGROUND AND PURPOSE: Sepsis-surviving adult individuals commonly develop immunosuppression and increased susceptibility to secondary infections, an outcome mediated by the axis IL-33/ILC2s/M2 macrophages/Tregs. Nonetheless, the long-term immune consequences of paediatric sepsis are indeterminate. We sought to investigate the role of age in the genesis of immunosuppression following sepsis. EXPERIMENTAL APPROACH: Here, we compared the frequency of Tregs, the activation of the IL-33/ILC2s axis in M2 macrophages and the DNA methylation of epithelial lung cells from post-septic infant and adult mice. Likewise, sepsis-surviving mice were inoculated intranasally with Pseudomonas aeruginosa or by subcutaneous inoculation of the B16 melanoma cell line. Finally, blood samples from sepsis-surviving patients were collected and the concentration of IL-33 and Tregs frequency were assessed. KEY RESULTS: In contrast to 6-week-old mice, 2-week-old mice were resistant to secondary infection and did not show impairment in tumour controls upon melanoma challenge. Mechanistically, increased IL-33 levels, Tregs expansion, and activation of ILC2s and M2-macrophages were observed in 6-week-old but not 2-week-old post-septic mice. Moreover, impaired IL-33 production in 2-week-old post-septic mice was associated with increased DNA methylation in lung epithelial cells. Notably, IL-33 treatment boosted the expansion of Tregs and induced immunosuppression in 2-week-old mice. Clinically, adults but not paediatric post-septic patients exhibited higher counts of Tregs and seral IL-33 levels. CONCLUSION AND IMPLICATIONS: These findings demonstrate a crucial and age-dependent role for IL-33 in post-sepsis immunosuppression. Thus, a better understanding of this process may lead to differential treatments for adult and paediatric sepsis.

Coverage gaps in empiric antibiotic regimens used to treat serious bacterial infections in neonates and children in Southeast Asia and the Pacific.

Background: High levels of antimicrobial resistance (AMR) are propagating deaths due to neonatal and paediatric infections globally. This is of particular concern in Southeast Asia and the Pacific, where healthcare resources are constrained and access to newer agents to treat multidrug-resistant pathogens is limited. Methods: To assess the coverage provided by commonly prescribed empiric antibiotic regimens for children in low- and middle-income countries in Southeast Asia and the Pacific, we built a weighted incidence syndromic combination antibiogram (WISCA), parameterised using data obtained from a systematic review of published literature incorporating WHO-defined SEARO and WPRO regions in Ovid MEDLINE, EMBASE, Global Health and PubMed. Susceptibility data for bacterial pathogens were extracted to provide coverage estimates for pre-specified antibiotics (aminopenicillins, gentamicin, third-generation cephalosporins and carbapenems), reported at the regional level. Findings: 6648 bacterial isolates from 11 countries across 86 papers were included in the Bayesian WISCA model, which weighted bacterial incidence and antimicrobial susceptibility of relevant isolates. Coverage provided by aminopenicillins in neonatal sepsis/meningitis was 26% (80% credible interval: 16-49) whilst gentamicin coverage was 45% (29-62). Third-generation cephalosporin coverage was only 29% (16-49) in neonatal sepsis/meningitis, 51% (38-64) in paediatric sepsis and 65% (51-77) in paediatric meningitis. Carbapenems were estimated to provide the highest coverage: 81% (65-90) in neonatal sepsis/meningitis, 83% (72-90) in paediatric sepsis and 79% (62-91) in paediatric meningitis. Interpretation: These findings reveal alarmingly high rates of resistance to commonly prescribed empirical therapies for neonatal and paediatric sepsis and meningitis in the Asia-Pacific region. Funding: This research was funded in whole, or in part, by the Wellcome Trust [220211]. For the purpose of Open Access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission. PCMW is supported by a National Health and Medical Research Council (NHMRC) Investigator Grant. NHMRC had no involvement in the design or conduct of the research.

Analysis and validation of diagnostic biomarkers and immune cell infiltration characteristics in pediatric sepsis by integrating bioinformatics and machine learning.

BACKGROUND: Pediatric sepsis is a complicated condition characterized by life-threatening organ failure resulting from a dysregulated host response to infection in children. It is associated with high rates of morbidity and mortality, and rapid detection and administration of antimicrobials have been emphasized. The objective of this study was to evaluate the diagnostic biomarkers of pediatric sepsis and the function of immune cell infiltration in the development of this illness. METHODS: Three gene expression datasets were available from the Gene Expression Omnibus collection. First, the differentially expressed genes (DEGs) were found with the use of the R program, and then gene set enrichment analysis was carried out. Subsequently, the DEGs were combined with the major module genes chosen using the weighted gene co-expression network. The hub genes were identified by the use of three machine-learning algorithms: random forest, support vector machine-recursive feature elimination, and least absolute shrinkage and selection operator. The receiver operating characteristic curve and nomogram model were used to verify the discrimination and efficacy of the hub genes. In addition, the inflammatory and immune status of pediatric sepsis was assessed using cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT). The relationship between the diagnostic markers and infiltrating immune cells was further studied. RESULTS: Overall, after overlapping key module genes and DEGs, we detected 402 overlapping genes. As pediatric sepsis diagnostic indicators, CYSTM1 (AUC = 0.988), MMP8 (AUC = 0.973), and CD177 (AUC = 0.986) were investigated and demonstrated statistically significant differences (P < 0.05) and diagnostic efficacy in the validation set. As indicated by the immune cell infiltration analysis, multiple immune cells may be involved in the development of pediatric sepsis. Additionally, all diagnostic characteristics may correlate with immune cells to varying degrees. CONCLUSIONS: The candidate hub genes (CD177, CYSTM1, and MMP8) were identified, and the nomogram was constructed for pediatric sepsis diagnosis. Our study could provide potential peripheral blood diagnostic candidate genes for pediatric sepsis patients.

Application of a sepsis flow chip (SFC) assay for the molecular diagnosis of paediatric sepsis.

A delay in detecting sepsis pathogens is a problematic issue for determining definitive antibiotic therapy for the causative pathogens. The gold standard method for sepsis is blood culture but this requires 3 days to detect the definitive pathogen. Molecular methods offer rapid identification of pathogens. We evaluated the use of sepsis flow chip (SFC) assay for identifying pathogens from children with sepsis. Blood samples from children with sepsis were collected and incubated in a culture device. Positive samples were subjected to amplification-hybridization using SFC assay and culture. A total of 94 samples from 47 patients were recovered, from which 25 isolates were recovered, including Klebsiella pneumoniae (11) and Staphylococcus epidermidis (6). From 25 positive blood culture bottles subjected to SFC assay, 24 genus/species and 18 resistance genes were detected. The sensitivity, specificity and conformity was 80, 94.2 and 94.68 % respectively. SFC assay offers promise to identify pathogens from positive blood culture in paediatric patients with sepsis and may support the antimicrobial stewardship programme in hospitals.

Emergence of mcr-8.2-harboring hypervirulent ST412 Klebsiella pneumoniae strain from pediatric sepsis: A comparative genomic survey.

Emerging mobile colistin resistance (mcr) genes pose a significant threat to public health for colistin was used as the last resort to treat multidrug-resistant (MDR) pathogenic bacterial infections. Hypervirulent Klebsiella pneumoniae (hvKP) is a clinically significant pathogen resulting in highly invasive infections, often complicated by devastating dissemination. Worryingly, the untreatable and severe infections caused by mcr-harbouring hvKP leave the selection of antibiotics for clinical anti-infective treatment in a dilemma. Herein, we screened 3,461 isolates from a tertiary teaching hospital from November 2018 to March 2021, and an mcr-8.2-harbouring hvKP FAHZZU2591 with a conjugative plasmid was identified from paediatric sepsis. This is the first report of MCR-8-producing hvKP from paediatric sepsis to our best knowledge. The susceptibility, genetic features, and plasmid profiles of the isolate were investigated. Further, we assessed the virulence potential of FAHZZU2591 and verified its pathogenicity and invasive capacity using a mouse model. The phylogenetic analysis of mcr-8-bearing K. pneumoniae revealed that China is the predominant reservoir of the mcr-8 gene, and the clinic is the primary source. Our work highlights the risk for the spread of mcr-positive hvKP in clinical, especially in paediatric sepsis, and the persistent surveillance of colistin-resistance hvKP is urgent.

Sepsis in children: state-of-the-art treatment.

Sepsis is a common, complex condition that requires early recognition and aggressive management to improve outcomes. There has been significant improvement in the management of sepsis and septic shock in the last decade; however, it continues to be a leading cause of mortality, morbidity and burden on healthcare services globally. Several guidelines with evidence-based recommendations for the management of children with septic shock and associated organ dysfunction have been produced with the objective of helping clinicians in various settings to provide standardised high-quality care. This article aims to increase awareness among all clinicians, including those working in emergency departments, general paediatric wards and primary care physicians, about the management of sepsis in children.

Protein C Pathway in Paediatric and Neonatal Sepsis.

Protein C plays a major role in the physiological regulation of coagulation pathways through inactivation of factor Va, factor VIIIa, and plasminogen activator inhibitor. Protein C is involved in the control of inflammation during sepsis, by inhibiting release of pro-inflammatory cytokines, thereby controlling neutrophil, and monocyte effects on injured tissue. Recombinant human activated protein C (rhAPC) reduced mortality in adult sepsis in earlier studies but had no significant benefit in more recent trials. Protein C levels are reduced during paediatric and neonatal sepsis, which may play a major role in the development of disseminated intravascular thrombosis, purpura fulminans, and multiorgan dysfunction. The role of protein C in paediatric sepsis requires further clinical and immunological evaluation to define the patient subgroups who may benefit from this therapy. Newer versions of rhAPC are under development with less risk of haemorrhage potentially broadening the scope of this intervention.

Individual and combined bioscore model of presepsin, procalcitonin, and high sensitive C - reactive protein as biomarkers for early diagnosis of paediatric sepsis.

BACKGROUND: Paediatric sepsis remains a major public health problem with significant morbidity and mortality especially in developing countries. Clinical symptoms associated with sepsis are unreliable and laboratory parameters unspecific, making an early diagnosis of paediatric sepsis difficult. The lack of definitive biomarker(s) for early diagnosis of sepsis further leads to the misuse of antibiotics. Diagnosis based on a single biomarker does not provide adequate accuracy. Subsequently, combining multiple biomarkers into a single score will help clinicians make a better diagnostic judgment. AIMS: This study for the first time evaluated the individual and combined diagnostic accuracy of procalcitonin (PCT), presepsin (sCD14-ST) and high sensitive C-reactive protein (hs-CRP) using a Bioscore model. MATERIALS AND METHODS: In a case control study conducted at the Paediatric Emergency Unit (PEU) and the Mother and Baby Unit (MBU) of Komfo Anokye Teaching Hospital (KATH), sixty (60) paediatric subjects aged zero to six (0-6) years, were diagnosed with sepsis using case-definition by the national neonatal bloodstream infection surveillance and Pediatric Sepsis Consensus Congress. Thirty (30) other paediatric subjects, aged and sex matched without sepsis or inflammatory conditions were used as controls. One-time blood sample was taken at the time of admission for blood culture and measurement of PCT, hs-CRP, and presepsin by ELISA. The Statistical Package for Social Sciences (SPSS release 20.0, Copyright ©SPSS Inc.) was used for analysis. RESULTS: Out of the sixty septic paediatric subjects, 14 patients (23.3%) had positive blood cultures (LCS) and 46 (76%) had negative for blood cultures (CS). Klebsiella spp. recorded the highest median levels of PCT, and hs-CRP while Pseudo. Aeruginasa recorded the highest of sCD14-ST levels. Significant elevations in PCT, sCD14-ST and hs-CRP levels were observed among septic cases in comparison to controls (p < 0.0001). Individually, PCT showed better accuracy (AUC = 78.7%) followed by hs-CRP (AUC = 78.4%) and sCD14-ST (AUC = 74.8%). Combination of PCT + hs-CRP had the highest accuracy (AUC = 80.1%) followed by hs-CRP + sCD14-ST (AUC = 77.2%), PCT + sCD14-ST + hs-CRP (AUC = 77.0%) and PCT + sCD14-ST (AUC = 75.9%).Conclusion: hs-CRP, PCT, and sCD14-ST are independent predictors of paediatric sepsis due to their high prognostic values. Moreover, Bioscore combination of these biomarkers was significantly associated with increased odds for sepsis. The incorporation of these biomarkers into routine diagnostic tests will aid in prompt diagnosis of paediatric sepsis.

[Paediatric sequential organ failure assessment (pSOFA) score: A new mortality prediction score in the paediatric intensive care unit]. / La escala pediátrica de evaluación del fallo multiorgánico secuencial (pSOFA): una nueva escala de predicción de la mortalidad en la unidad de cuidados intensivos pediátricos.

OBJECTIVES: To assess performance of the age-adapted SOFA score in children admitted into Paediatric Intensive Care Units (PICUs) and whether the SOFA score can compete with the systemic inflammatory response syndrome (SIRS) in diagnosing sepsis, as recommended in the Sepsis-3 consensus definitions. METHODS: Two-centre prospective observational study in 281 children admitted to the PICU. We calculated the SOFA, Pediatric Risk of Mortality (PRISM), and Pediatric Index of Mortality-2 (PIM2) scores and assessed for the presence of SIRS at admission. The primary outcome was 30-day mortality. RESULTS: The SOFA score was higher in nonsurvivors (P<.001) and mortality increased progressively across patient subgroups from lower to higher SOFA scores. The receiver operating characteristic (ROC) curve analysis revealed that the area under the curve (AUC) of the SOFA score for predicting 30-day mortality was 0.89, compared to AUCs of 0.84 and 0.79 for the PRISM and PIM2 scores, respectively. The AUC of the SOFA score for predicting a prolonged stay in the PICU was 0.67. The SOFA score was correlated to the PRISM score (rs=0.59) and the PIM2 score (rs=0.51). In children with infection, the AUC of the SOFA score for predicting mortality was 0.87 compared to an AUC of 0.60 using SIRS. The diagnosis of sepsis applying a SOFA cutoff of 3 points predicted mortality better than both the SIRS and the SOFA cutoff of 2 points recommended by the Sepsis-3 consensus. CONCLUSIONS: The SOFA score at admission is useful for predicting outcomes in the general PICU population and is more accurate than SIRS for definition of paediatric sepsis.