Systemic bacterial and fungal infections in infants in Australian neonatal units. Australian Study Group for Neonatal Infections

Anti-inflammatory and anti-biotic drug metronidazole loaded ZIF-90 nanoparticles as a pH responsive drug delivery system for improved pediatric sepsis management

Sepsis is a life-threatening disease caused by the dis-functioning of the immune response to pathogenic infections. Despite, the discovery of modern therapeutics and treatments of sepsis are lacking due to the resistance of pathogens. Metronidazole is an antibiotic commonly used to treat bacterial infections, but usage is limited and challenging by a short half-life period. In this research work, fabricate a pH-responsive drug delivery system for controlled release of metronidazole targeted molecules. We exemplified that, the encapsulation of hydrophilic metronidazole drug within a hydrophobic ZIF-90 framework can be enhanced the pH-responsive drug release under acidic conditions. The ZIF-90 frameworks only decompose in under acidic solutions, they are highly stable in physiological conditions. The pH-responsive protonation mechanism of ZIF-90 frameworks promotes the quick release of metronidazole within cells. The antimicrobial proficiency of zinc and metronidazole will expose a synergistic effect in ROS-mediated bacterial inhibition and auto-immunity boosting of normal cells. In vitro, antibacterial activity results revealed that the MI@ZIF-90 nano drug delivery system effectively eradicated human infectious pathogens at the lowest concentrations. In anti-fungal activity, studies show excellent growth inhibition against human pathogenic fungi Aspergillus fumigatus and Candida albicans. Finally, the PBMC cytocompatibility study concludes, that the fabricated MI@ZIF-90 drug delivery system is non-toxic to biomedical applications. The overall research findings highlight the design of a smart drug delivery system for sepsis treatment. In future it will be an efficient, low-cost, and biocompatible pharmaceutics for pediatric sepsis management processes.

Variation in hospital morbidities in an Australian neonatal intensive care unit network

OBJECTIVE

There is an expectation among the public and within the profession that the performance and outcome of neonatal intensive care units (NICUs) should be comparable between centres with a similar setting. This study aims to benchmark and audit performance variation in a regional Australian network of eight NICUs.

DESIGN

Cohort study using prospectively collected data.

SETTING

All eight perinatal centres in New South Wales and the Australian Capital Territory, Australia.

PATIENTS

All live-born infants born between 23⁺⁰ and 31⁺⁶ weeks gestation admitted to one of the tertiary perinatal centres from 2007 to 2020 (n=12 608).

MAIN OUTCOME MEASURES

Early and late confirmed sepsis, intraventricular haemorrhage, medically and surgically treated patent ductus arteriosus, chronic lung disease (CLD), postnatal steroid for CLD, necrotising enterocolitis, retinopathy of prematurity (ROP), surgery for ROP, hospital mortality and home oxygen.

RESULTS

NICUs showed variations in maternal and neonatal characteristics and resources. The unadjusted funnel plots for neonatal outcomes showed apparent variation with multiple centres outside the 99.8% control limits of the network values. The hierarchical model-based risk-adjustment accounting for differences in patient characteristics showed that discharged home with oxygen is the only outcome above the 99.8% control limits.

CONCLUSIONS

Hierarchical model-based risk-adjusted estimates of morbidity rates plotted on funnel plots provide a robust and straightforward visual graphical tool for presenting variations in outcome performance to detect aberrations in healthcare delivery and guide timely intervention. We propose using hierarchical model-based risk adjustment and funnel plots in real or near real-time to detect aberrations and start timely intervention.

Current understanding and future potential applications of cerebral microvascular imaging in infants

Microvascular imaging is an advanced Doppler ultrasound technique that detects slow flow in microvessels by suppressing clutter signal and motion-related artifacts. The technique has been applied in several conditions to assess organ perfusion and lesion characteristics. In this pictorial review, we aim to describe current knowledge of the technique, particularly its diagnostic utility in the infant brain, and expand on the unexplored but promising clinical applications of microvascular imaging in the brain with case illustrations.

C-reactive protein as a predictor of meningitis in early onset neonatal sepsis: a single unit experience

Objectives To determine whether there is a cut off value of serum C-reactive protein (CRP) associated with a higher risk of meningitis in suspected early onset sepsis (EOS) (onset birth to 7 days of life). Methods A retrospective cohort study on neonates admitted in neonatal intensive care unit at McMaster Children's Hospital from January 2010 to 2017 and had lumbar puncture (LP) and CRP for workup of EOS. Included subjects had either (a) non-traumatic LP or (b) traumatic LP with cerebral spinal fluid (CSF) polymerase chain reaction or gram stain or culture-positive or had received antimicrobials for 21 days. Excluded were CSF done for metabolic errors, before cytomegalovirus (CMV) treatment; from ventriculo-peritoneal (VP) shunts; missing data and contamination. Neonates were classified into definite and probable meningitis and on the range of CRP. We calculated sensitivity, specificity, and likelihood ratios for CRP values; and area under the receiver operating characteristic (AUROC) curve. Results Out of 609 CSF samples, 184 were eligible (28 cases of definite or probable meningitis and 156 controls). Sensitivity, specificity, predictive values, likelihood ratios, and AUROC were too low to be of clinical significance to predict meningitis in EOS. Conclusions Serum CRP values have poor discriminatory power to distinguish between subjects with and without meningitis, in symptomatic EOS.

Early-Onset Neonatal Sepsis

Despite the great progress made in neonatal and perinatal medicine over the last couple of decades, sepsis remains one of the main causes of morbidity and mortality. Sepsis in pediatric population was defined at the Pediatric Sepsis Consensus Conference in 2005. There is still no consensus on the definition of neonatal sepsis. Neonatal sepsis is a sepsis that occurs in the neonatal period. According to the time of occurrence, neonatal sepsis can be of early onset, when it occurs within the first 72 hours of birth and results from vertical transmission, and of late onset, in which the source of infection is found most often in the environment and occurs after the third day of life. The most common causes of early-onset sepsis are Group B Streptococcus (GBS) and E. coli. Risk factors can be mother-related and newborn-related. Clinical symptoms and signs of sepsis are quite unspecific. The dysfunction of different organs may imitate sepsis. On the other hand, infectious and non-infectious factors may exist simultaneously. The start of the antimicrobial therapy in any newborn with suspected sepsis should not be delayed. Pentoxifylline may have potential benefits in preterm newborns with sepsis. The only proven intervention that has been shown to reduce the risk of early-onset neonatal sepsis is intrapartum intravenous antibiotic administration to prevent GBS infection. It is still a great challenge to discontinue antibiotic treatment in non-infected newborns as soon as possible, because any extended antibiotic use may later be associated with other pathological conditions.

Neonatal Sepsis

Purpose of Review

Neonatal sepsis is a diagnosis made in infants less than 28 days of life and consists of a clinical syndrome that may include systemic signs of infection, circulatory shock, and multisystem organ failure.

Recent Findings

Commonly involved bacteria include Staphylococcus aureus and Escherichia coli. Risk factors include central venous catheter use and prolonged hospitalization. Neonates are at significant risk of delayed recognition of sepsis until more ominous clinical findings and vital sign abnormalities develop. Blood culture remains the gold standard for diagnosis.

Summary

Neonatal sepsis remains an important diagnosis requiring a high index of suspicion. Immediate treatment with antibiotics is imperative.

C-Reactive Protein (CRP) levels in neonatal meningitis in England: an analysis of national variations in CRP cut-offs for lumbar puncture

Background

Recent National Institute for Health and Care Excellence (NICE) CG149 guidelines suggest considering performing a lumbar puncture (LP) to investigate for meningitis in early-onset sepsis in a neonate when a C-reactive protein (CRP) level >10mg/L, but the evidence for this recommendation is poorly defined.

Methods

Data on trust-wide LP protocols, neonatal meningitis incidence, lumbar punctures, and CRP levels seen in cases of neonatal meningitis were asked of all 137 trusts in England that recorded a birth in 2017. Our local Kingston Hospital data on every LP performed was obtained to estimate the specificity of CRP rises.

Results

73/123 (59.3%) of trusts follow the NICE CG149 recommendation of considering an LP if the CRP >10mg/L. The national incidence of neonatal meningitis was 0.467/1,000 births, and an LP was performed in 1.37% of all babies, which was significantly higher in trusts considering the CRP > 10mg/L cut-off. A CRP > 10mg/L cut-off sensitivity was 88.9% based on the highest CRP level 4 days around the LP from national data of 199 cases; specificity was 78.8% based on our single-unit analysis.

Conclusions

Proposing a universal CRP > 10mg/L cut-off for a lumbar puncture has been counter-productive in England. Following it generates significantly more LPs, to the point that 40.7% of trusts have chosen not to follow it. It also has poor sensitivity missing over 11% of meningitis. We therefore do not recommend a universal cut-off, rather considering the whole clinical picture (including prematurity) when considering whether to do an LP.

Network-based analysis of diagnosis progression patterns using claims data

In recent years, several network models have been introduced to elucidate the relationships between diseases. However, important risk factors that contribute to many human diseases, such as age, gender and prior diagnoses, have not been considered in most networks. Here, we construct a diagnosis progression network of human diseases using large-scale claims data and analyze the associations between diagnoses. Our network is a scale-free network, which means that a small number of diagnoses share a large number of links, while most diagnoses show limited associations. Moreover, we provide strong evidence that gender, age and disease class are major factors in determining the structure of the disease network. Practically, our network represents a methodology not only for identifying new connectivity that is not found in genome-based disease networks but also for estimating directionality, strength, and progression time to transition between diseases considering gender, age and incidence. Thus, our network provides a guide for investigators for future research and contributes to achieving precision medicine.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effect of antibiotic use on antimicrobial antibiotic resistance and late-onset neonatal infections over 25 years in an Australian tertiary neonatal unit

BACKGROUND

Antibiotic resistance is a worldwide problem. We describe 25 years of responsible antibiotic use in a tertiary neonatal unit.

METHODS

Data on neonatal infections and antibiotic use were collected prospectively from 1990 to 2014 at a single tertiary Sydney neonatal intensive care unit attached to a maternity unit. There are approximately 5500 deliveries and 900 nursery admissions per year.

RESULTS

The mean annual rate of late-onset sepsis was 1.64 episodes per 100 admissions. The mean number of late-onset sepsis episodes per admission to the neonatal unit decreased by 4.0% per year (95% CI 2.6% to 5.4%; p<0.0001) and occurred particularly in infants born weighing <1500 g. No infants with negative cultures relapsed with sepsis when antibiotics were stopped after 48-72 hours. Antibiotic use decreased with time. The proportion of colonising methicillin-resistant Staphylococcus aureus isolates decreased by 7.4% per year (95% CI 0.2% to 14.1%; p=0.043). The proportion of colonising Gram-negative bacilli isolates resistant to either third-generation cephalosporins or gentamicin increased by 2.9% per year (95% CI 1.0% to 4.9%; p=0.0035). Most were cephalosporin-resistant; gentamicin resistance was rare. An average of one baby per year died from late-onset sepsis, the rate not varying significantly over time. The mortality from episodes of late-onset sepsis was 25 of 332 (7.5%).

CONCLUSION

Stopping antibiotics after 2-3 days if neonatal systemic cultures are negative is safe. However, it does not prevent the emergence of cephalosporin-resistant Gram-negative organisms.

Late-onset neonatal sepsis in Arab states in the Gulf region: two-year prospective study

OBJECTIVES

This study aimed to investigate the incidence of late-onset sepsis (LOS) in neonatal intensive care units (NICUs) in Arab states in the Gulf region and to describe the main causative organisms and their antibiotic resistance.

METHODS

This observational prospective cohort study was conducted over a 2-year period in five NICUs in Kuwait, Saudi Arabia, and the United Arab Emirates. LOS was defined as the growth of a single potentially pathogenic organism from blood or cerebrospinal fluid in infants >3days of age with clinical and laboratory findings consistent with infection.

RESULTS

Seven hundred and eighty-five cases of LOS occurred among 67 474 live births. The overall incidence of LOS was 11.63 (95% confidence interval (CI) 10.84-12.47) per 1000 live births, or 56.14 (95% CI 52.38-60.08) per 1000 admissions. Coagulase-negative staphylococci and Klebsiella spp were the most common organisms, causing 272 (34.65%) and 179 (22.80%) of LOS cases, respectively. No evidence of a seasonal variation in the incidence of Klebsiella spp or in the incidence of all Gram-negative organisms was found. More than half of the Klebsiella spp were resistant to third-generation cephalosporins.

CONCLUSION

LOS poses a major burden in this area, which could be due to the increasing care of premature babies. Gram-negative organisms, particularly Klebsiella spp, are having an increasing role in LOS in this region, with high levels of resistance to third-generation cephalosporins. NICUs in the area should create a platform through which to share experience in reducing neonatal sepsis and contribute to a common antibiotic stewardship program.

Culture-proven early-onset neonatal sepsis in Arab states in the Gulf region: two-year prospective study

OBJECTIVE

To investigate the incidence and the pattern of causative organisms of culture-proven early-onset sepsis (EOS) in Arab states in the Gulf region.

METHODS

Five neonatal care units participated in this 2-year prospective study in Kuwait, the United Arab Emirates, and Saudi Arabia. Data were collected prospectively using a standardized data collection form. EOS was defined as the growth of a single potentially pathogenic organism from blood or cerebrospinal fluid in infants within 72h of birth, with clinical and laboratory findings consistent with infection.

RESULTS

Out of 67 474 live births, 102 cases of EOS occurred. The overall incidence of EOS was 1.5 (95% confidence interval 1.2-1.8) per 1000 live-births, ranging from 2.64 per 1000 live-births in Kuwait to 0.40 per 1000 live-births in King Abdulaziz Hospital in Saudi Arabia. The most common causative organism of EOS was group B Streptococcus (GBS; 60.0%), followed by Escherichia coli (13%). The incidence of invasive GBS disease was 0.90 per 1000 live-births overall and ranged from 1.4 per 1000 live-births in Kuwait to 0.6 per 1000 live-births in Dubai Hospital.

CONCLUSIONS

The incidence of EOS and the patterns of the causative organisms in the Arab states in the Gulf region are similar to those in developed countries before the era of intrapartum antibiotic prophylaxis. Efforts should be made to improve intrapartum antibiotic prophylaxis in the Arab state setting, which could avert large numbers of GBS infections.

Early settlers: which E. coli strains do you not want at birth?

The intestinal microbiota exerts vital biological processes throughout the human lifetime, and imbalances in its composition have been implicated in both health and disease status. Upon birth, the neonatal gut moves from a barely sterile to a massively colonized environment. The development of the intestinal microbiota during the first year of life is characterized by rapid and important changes in microbial composition, diversity, and magnitude. The pioneer bacteria colonizing the postnatal intestinal tract profoundly contribute to the establishment of the host-microbe symbiosis, which is essential for health throughout life. Escherichia coli is one of the first colonizers of the gut after birth. E. coli is a versatile population including harmless commensal, probiotic strains as well as frequently deadly pathogens. The prevalence of the specific phylogenetic B2 group, which encompasses both commensal and extra- or intraintestinal pathogenic E. coli strains, is increasing among E. coli strains colonizing infants quickly after birth. Fifty percent of the B2 group strains carry in their genome the pks gene cluster encoding the synthesis of a nonribosomal peptide-polyketide hybrid genotoxin named colibactin. In this review, we summarize both clinical and experimental evidence associating the recently emerging neonatal B2 E. coli population with several pathology and discuss how the expression of colibactin by both normal inhabitants of intestinal microflora and virulent strains may darken the borderline between commensalism and pathogenicity.

Endocan and Soluble Triggering Receptor Expressed on Myeloid Cells-1 as Novel Markers for Neonatal Sepsis

BACKGROUND

Neonatal sepsis is an important cause of neonatal morbidity and mortality in the neonatal intensive care unit. Soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) has been evaluated in sepsis and septic shock, and it was found to be valuable in distinguishing septic cases from nonseptic cases. Endocan is constitutively expressed by endothelial cells, and high levels of endocan may be of relevance for the promotion of systemic inflammation. The aim of this study was to investigate whether the levels of sTREM-1 and endocan were increased in late-onset neonatal sepsis.

METHODS

Patients were classified into septic and nonseptic groups. Blood was collected from a peripheral vein of all septic newborns and healthy newborns at the time of initial laboratory evaluation before any treatment, and within 48-72 hours after initiation of treatment. Serum sTREM-1 and endocan measurements were performed when the study was finished.

RESULTS

The study population comprised of 50 neonates: 20 nonseptic neonates and 30 septic neonates. The groups were similar with regards to baseline characteristics. The initial measurements of interleukin-6 (IL-6), sTREM-1, endocan, and immature/total neutrophil ratio (I/T ratio) were significantly higher in septic neonates in comparison with nonseptic neonates. Receiver operating characteristic (ROC) curve analyses revealed that IL-6, sTREM-1, endocan, and I/T ratio resulted in significant areas under the curve (AUC) with respect to early identification of septic neonates. Soluble TREM-1 and IL-6 performed best to distinguish septic neonates from nonseptic neonates. Univariate logistic regression analysis showed that increased IL-6 and sTREM-1 were strong predictors of neonatal late-onset sepsis.

CONCLUSION

Serum sTREM-1, IL-6, endocan levels, and I/T ratio increased in septic neonates. However, the diagnostic accuracy of circulating sTREM-1 seemed to be better than endocan and I/T ratio, but lower than IL-6.

Reappraisal of guidelines for management of neonates with suspected early-onset sepsis

Since 1992, professional societies or public health agencies in the United States^– and elsewhere^– have issued several generations of recommendations for prevention or management of early-onset neonatal sepsis (EOS). Despite those efforts, recommendations remain inconsistent, clarifications are necessary, local adaptations are common, and compliance rates are low. We postulate that lack of consensus, especially regarding postnatal management of the neonate, is largely a result of two sets of factors. First, obstetrical prevention strategies have substantially reduced incidence of EOS, potentially changing the utility of predictive strategies based on risk factors. Second, recent data better delineate relationships among risk factors, clinical signs, and EOS, suggesting that risk predictors may have different utilities in different groups. The purpose of this commentary is to explore these questions and to suggest new approaches to management of newborns who may be at risk for EOS.

Early-onset neonatal sepsis

Early-onset sepsis remains a common and serious problem for neonates, especially preterm infants. Group B streptococcus (GBS) is the most common etiologic agent, while Escherichia coli is the most common cause of mortality. Current efforts toward maternal intrapartum antimicrobial prophylaxis have significantly reduced the rates of GBS disease but have been associated with increased rates of Gram-negative infections, especially among very-low-birth-weight infants. The diagnosis of neonatal sepsis is based on a combination of clinical presentation; the use of nonspecific markers, including C-reactive protein and procalcitonin (where available); blood cultures; and the use of molecular methods, including PCR. Cytokines, including interleukin 6 (IL-6), interleukin 8 (IL-8), gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α), and cell surface antigens, including soluble intercellular adhesion molecule (sICAM) and CD64, are also being increasingly examined for use as nonspecific screening measures for neonatal sepsis. Viruses, in particular enteroviruses, parechoviruses, and herpes simplex virus (HSV), should be considered in the differential diagnosis. Empirical treatment should be based on local patterns of antimicrobial resistance but typically consists of the use of ampicillin and gentamicin, or ampicillin and cefotaxime if meningitis is suspected, until the etiologic agent has been identified. Current research is focused primarily on development of vaccines against GBS.

Role of guidelines on length of therapy in chorioamnionitis and neonatal sepsis

BACKGROUND AND OBJECTIVE

Chorioamnionitis (CAM) is a major risk factor for neonatal sepsis. At our institution, neonates exposed to CAM and intrapartum antibiotics are treated with prolonged antimicrobial therapy if laboratory values are abnormal despite a sterile blood culture. Recently, the Committee on the Fetus and Newborn (COFN) recommended a similar strategy for treating neonates exposed to CAM. Our objective was to determine the frequency of abnormal laboratory parameters in term and late-preterm neonates exposed to CAM and evaluate the implication of recent COFN guidelines.

METHODS

This retrospective data analysis included late-preterm and term neonates exposed to CAM. Laboratory parameters, clinical symptoms and the number of infants treated with prolonged antibiotics were determined.

RESULTS

A total of 554 infants met the inclusion criteria. Eighty-three infants (14.9%) had an abnormal immature to total neutrophil ratio (>0.2) and 121 infants (22%) had an abnormal C-reactive protein level (>1 mg/dL) at 12 hours of age. A total of 153 infants (27.6%) had an abnormal immature to total neutrophil ratio and/or abnormal C-reactive protein level at 12 hours of age. Only 4 (0.7%) of 554 infants had a positive blood culture result. A total of 134 (24.2%) infants were treated with prolonged antibiotics (112 [20.2%] were treated solely based on abnormal laboratory data). Lumbar puncture was performed in 120 (21.6%) infants.

CONCLUSIONS

When managed by using a strategy similar to recent COFN guidelines, a large number of term and late-preterm infants exposed to CAM who had sterile blood culture findings were treated with prolonged antibiotic therapy due to abnormal laboratory findings. They were also subjected to additional invasive procedures and had a longer duration of hospitalization.

Inflammatory and haematological markers in the maternal, umbilical cord and infant circulation in histological chorioamnionitis

BACKGROUND

The relationship between histological chorioamnionitis and haematological and biochemical markers in mothers and infants at delivery, and in infants postnatally, is incompletely characterised. These markers are widely used in the diagnosis of maternal and neonatal infection. Our objective was to investigate the effects of histological chorioamnionitis (HCA) on haematological and biochemical inflammatory markers in mothers and infants at delivery, and in infants post-delivery.

METHODS

Two hundred and forty seven mothers, delivering 325 infants, were recruited at the only tertiary perinatal centre in Western Australia. Placentae were assessed for evidence of HCA using a semi-quantitative scoring system. Maternal high sensitivity C-reactive protein (hsCRP), procalcitonin, and umbilical cord hsCRP, procalcitonin, white cell count and absolute neutrophil count were measured at delivery. In infants where sepsis was clinically suspected, postnatal CRP, white cell count and absolute neutrophil count were measured up to 48 hours of age. The effect of HCA on maternal, cord and neonatal markers was evaluated by multivariable regression analysis.

RESULTS

The median gestational age was 34 weeks and HCA was present in 26 of 247 (10.5%) placentae. Mothers whose pregnancies were complicated by HCA had higher hsCRP (median 26 (range 2-107) versus 5.6 (0-108) mg/L; P<0.001). Histological chorioamnionitis was associated with higher umbilical cord hsCRP (75(th) percentile 2.91 mg/L (range 0-63.9) versus 75(th) percentile 0 mg/L (0-45.6); P<0.001) and procalcitonin (median 0.293 (range 0.05-27.37) versus median 0.064 (range 0.01-5.24) ug/L; P<0.001), with a sustained increase in neonatal absolute neutrophil count (median 4.5 (0.1-26.4)×10(9)/L versus 3.0 (0.1-17.8)×10(9)/L), and CRP up to 48 hours post-partum (median 10 versus 6.5 mg/L) (P<0.05 for each).

CONCLUSION

Histological chorioamnionitis is associated with modest systemic inflammation in maternal and cord blood. These systemic changes may increase postnatally, potentially undermining their utility in the diagnosis of early-onset neonatal infection.

Inflammatory and haematological markers in the maternal, umbilical cord and infant circulation in histological chorioamnionitis

Background

The relationship between histological chorioamnionitis and haematological and biochemical markers in mothers and infants at delivery, and in infants postnatally, is incompletely characterised. These markers are widely used in the diagnosis of maternal and neonatal infection. Our objective was to investigate the effects of histological chorioamnionitis (HCA) on haematological and biochemical inflammatory markers in mothers and infants at delivery, and in infants post-delivery.

Methods

Two hundred and forty seven mothers, delivering 325 infants, were recruited at the only tertiary perinatal centre in Western Australia. Placentae were assessed for evidence of HCA using a semi-quantitative scoring system. Maternal high sensitivity C-reactive protein (hsCRP), procalcitonin, and umbilical cord hsCRP, procalcitonin, white cell count and absolute neutrophil count were measured at delivery. In infants where sepsis was clinically suspected, postnatal CRP, white cell count and absolute neutrophil count were measured up to 48 hours of age. The effect of HCA on maternal, cord and neonatal markers was evaluated by multivariable regression analysis.

Results

The median gestational age was 34 weeks and HCA was present in 26 of 247 (10.5%) placentae. Mothers whose pregnancies were complicated by HCA had higher hsCRP (median 26 (range 2–107) versus 5.6 (0–108) mg/L; P<0.001). Histological chorioamnionitis was associated with higher umbilical cord hsCRP (75^th percentile 2.91 mg/L (range 0–63.9) versus 75^th percentile 0 mg/L (0–45.6); P<0.001) and procalcitonin (median 0.293 (range 0.05–27.37) versus median 0.064 (range 0.01–5.24) ug/L; P<0.001), with a sustained increase in neonatal absolute neutrophil count (median 4.5 (0.1–26.4)×10⁹/L versus 3.0 (0.1–17.8)×10⁹/L), and CRP up to 48 hours post-partum (median 10 versus 6.5 mg/L) (P<0.05 for each).

Conclusion

Histological chorioamnionitis is associated with modest systemic inflammation in maternal and cord blood. These systemic changes may increase postnatally, potentially undermining their utility in the diagnosis of early-onset neonatal infection.

Assisting women to make informed choices about screening for Group B Streptococcus in pregnancy: a critical review of the evidence

The approach to the prevention of early onset GBS disease in the newborn varies considerably from country to country. The Centre for Disease Control in the United States advocates universal culture based screening with the administration of intra-partum antibiotics, usually benzylpenicillin or ampicillin, to women who are colonised with GBS. National groups in the UK and New Zealand advocate a risk-based approach where intra-partum antibiotics are given to women with identified risk factors. The Canadian Taskforce on preventive health care has identified a third approach; where intra-partum antibiotics are given to women with a positive GBS culture and an identified risk factor. There are no national guidelines or consensus in Australia. The aim of this paper is to explore the evidence for screening and intrapartum prophylaxis for GBS. The three main methods of detection and management of GBS in pregnancy are described and the implications for women and midwifery practice are addressed. It is hoped that this discussion will provide women, midwives and other clinicians with a summary of the evidence, risks and benefits to enable informed decision making.

Prevention of neonatal group B streptococcus disease in the 21st century

There have been significant reductions in early-onset neonatal group B streptococcus (GBS) disease following implementation of maternal intrapartum antibiotic prophylaxis (IAP) policies. Nevertheless, GBS remains a leading cause of neonatal sepsis in Australia and New Zealand resulting in considerable morbidity and mortality, particularly among preterm infants. In the United States, the universal screening-based approach for identifying women for IAP results in apparently lower rates of early-onset neonatal GBS infection than risk-based assessment. In addition, IAP has altered the profile of newborn infants who develop early-onset disease. Many affected infants lack the typical intrapartum risk factors for GBS infection, are born to mothers with a negative GBS screen or represent missed opportunities for prevention. Clinicians should remain alert for signs of sepsis in any newborn infant. We provide an update of GBS preventative management strategies in the perinatal period taking into account recent United States, Australian and New Zealand guidelines.

Incidence, aetiology and resistance of late-onset neonatal sepsis: a five-year prospective study

AIM

Investigate the incidence, etiological pattern and the antimicrobial resistance of late-onset neonatal infections over a period of 5 years.

METHODS

Longitudinal audit of neonatal sepsis from January 2005 to December 2009, in the main maternity hospital in Kuwait. Late-onset neonatal infection was defined as the culture of a single potentially pathogenic organism from blood or cerebrospinal fluid from an infant older than 6 days in association with clinical or laboratory findings consistent with infection.

RESULTS

The overall incidence was 16.9 (95% confidence interval: 15.8-18.0) episodes per 1000 live births. The commonest pathogen was coagulase-negative Staphylococcus, 339 (35.7%), while Klebsiella was the most common gram-negative infection, 178 (18.8%). Escherichia coli, Enterococcus and Enterobacter spp were each responsible for 6% of all infections. Candida caused 104 (11.0%) infections. The general pattern of infection remained unchanged over the study period. Case fatality was 11.7% (95% confidence interval: 9.7-13.9%) and was high for Pseudomonas (18.4%) and Candida (22.1%) infections. Approximately 24 and 20% of Klebsiella infections were resistant to cefotaxime and gentamicin, respectively, while 28 and 24% of Escherichia coli infections were resistant to cefotaxime and gentamicin, respectively.

CONCLUSION

The incidence of late-onset infection in Kuwait is high, resembling that in resource-poor countries. The high incidence coupled with low case fatality provides an example for settings where tertiary care is introduced without strict measures against nosocomial infections. Prevention against nosocomial infections in neonatal units has the potential to further reduce neonatal mortality in these settings.

Management of neonates with suspected or proven early-onset bacterial sepsis

With improved obstetrical management and evidence-based use of intrapartum antimicrobial therapy, early-onset neonatal sepsis is becoming less frequent. However, early-onset sepsis remains one of the most common causes of neonatal morbidity and mortality in the preterm population. The identification of neonates at risk for early-onset sepsis is frequently based on a constellation of perinatal risk factors that are neither sensitive nor specific. Furthermore, diagnostic tests for neonatal sepsis have a poor positive predictive accuracy. As a result, clinicians often treat well-appearing infants for extended periods of time, even when bacterial cultures are negative. The optimal treatment of infants with suspected early-onset sepsis is broad-spectrum antimicrobial agents (ampicillin and an aminoglycoside). Once a pathogen is identified, antimicrobial therapy should be narrowed (unless synergism is needed). Recent data suggest an association between prolonged empirical treatment of preterm infants (≥5 days) with broad-spectrum antibiotics and higher risks of late onset sepsis, necrotizing enterocolitis, and mortality. To reduce these risks, antimicrobial therapy should be discontinued at 48 hours in clinical situations in which the probability of sepsis is low. The purpose of this clinical report is to provide a practical and, when possible, evidence-based approach to the management of infants with suspected or proven early-onset sepsis.

MR imaging of neonatal brain infections

Infections of the brain in the postnatal period differ from those in older children as a result of a combination of distinct epidemiologic factors in general, and immaturity of neonatal brain and immunologic host response in particular. It has been recognized that clinical and neurologic signs are often nonspecific, sometimes scarce, and seldom correlate with the extent of neuroimaging findings, thus warranting an early MR imaging examination in the course of the disease, enabling rapid therapy institution and better clinical outcome. This article reviews most of postnatal pathogen agents involved in neonatal brain infections, related physiopathology, and neuroimaging findings.

Granulocyte transfusions for neonates with confirmed or suspected sepsis and neutropenia

BACKGROUND

Neonates have immature granulopoiesis, which frequently results in neutropenia after sepsis. Neutropaenic septic neonates have a higher mortality than non-neutropenic septic neonates. Therefore, granulocyte transfusion to septic neutropenic neonates may improve outcomes.

OBJECTIVES

The primary objective was to determine the effect of granulocyte or buffy coat transfusions as adjuncts to antibiotics, after confirmed or suspected sepsis in neutropenic neonates, on all-cause mortality during hospital stay and neurological outcome at ≥ year of age. Secondary objectives were to determine the effects of granulocyte transfusions on length of hospital stay in survivors to discharge, adverse effects and immunologic outcomes at ≥ year of age.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (The Cochrane Library), MEDLINE, EMBASE and CINAHL, proceedings of the PAS conferences and ongoing trials at clinicaltrials.gov and clinical-trials.com were searched in July 2011.

SELECTION CRITERIA

Studies where neutropenic neonates with suspected or confirmed sepsis were randomised or quasi-randomised to granulocyte or buffy coat transfusions at any dose or duration, and reporting any outcome of interest were included.

DATA COLLECTION AND ANALYSIS

Relative risk (RR) and risk difference (RD) with 95% confidence intervals using the fixed effects model were reported for dichotomous outcomes. Pre-specified subgroup analyses were performed.

MAIN RESULTS

Four trials were eligible for inclusion. Forty-four infants with sepsis and neutropenia were randomised in three trials to granulocyte transfusions or placebo/no transfusion. In another trial, 35 infants with sepsis and neutropenia on antibiotics were randomised to granulocyte transfusion or IVIG.When granulocyte transfusion was compared with placebo or no transfusion, there was no significant difference in 'all-cause mortality' (three trials; typical RR 0.89, 95% CI 0.43 to 1.86; typical RD -0.05, 95% CI -0.31 to 0.21).When granulocyte transfusion was compared with intravenous immunoglobulin (one trial), there was a reduction in 'all-cause mortality' of borderline statistical significance (RR 0.06, 95% CI 0.00 to 1.04; RD -0.34, 95% CI -0.60 to -0.09; NNT 2.7, 95% CI 1.6 to 9.1).Pulmonary complications were the only adverse effect reported in the trials that used buffy coat transfusions. None of the trials reported on neurological outcome at one year of age or later, length of hospital stay in survivors to discharge or immunological outcome at one year of age or later.

AUTHORS' CONCLUSIONS

Currently, there is inconclusive evidence from randomised controlled trials (RCTs) to support or refute the routine use of granulocyte transfusions in neutropenic, septic neonates. Researchers are encouraged to conduct adequately powered multi-centre trials of granulocyte transfusions in neutropenic septic neonates.

Healthcare-associated infections in a neonatal intensive care unit in Turkey in 2008: incidence and risk factors, a prospective study

In this study, we have prospectively recorded healthcare-associated infections (HAIs) in NICU and found incidence density as 18 infections per 1000 patient days. Of the infections, 51.3% was bacteriemia (BSI), and 45.1% was ventilator-associated pneumonia (VAP). Gram-negative microorganisms were predominant in VAP and Staphylococcus epidermidis was the leading microorganism (53.0% of BSIs) in BSIs. Multivariate logistic regression analysis showed the importance of hood O(2) use in days (RR: 1.3) and total parenteral nutrition use in days (RR: 1.09) for BSIs. Umbilical arterial catheterization in days (RR: 1.94), ventilator use in days (RR: 1.05), chest tube (RR: 12.55), orogastric feeding (RR: 3.32) and total parenteral nutrition in days (RR: 1.05) were found to be significantly associated with VAP. In conclusion, incidence density in our unit is high and Gram-negative rods are predominant similar to developing countries. These results strongly suggest improving measures of prevention and control of HAIs in the unit.

Neonatal brain infections

Infections of the brain in the neonatal period differ considerably from infections in the older child, due to a variety of age-specific factors that are related not only to the child, but also to the mother, and to specific pathogenic organisms. It has been recognized that clinical and neurological signs are often non-specific, sometimes scarce, and seldom correlate with the extent of neuroimaging findings, thus warranting early imaging to ensure timely therapy and improved outcome.

Phagocytic ability of neutrophils and monocytes in neonates

Background

Infections by a variety of pathogens are a significant cause of morbidity and mortality during perinatal period. The susceptibility of neonates to bacterial infections has been attributed to immaturity of innate immunity. It is considered that one of the impaired mechanisms is the phagocytic function of neutrophils and monocytes. The purpose of the present study was to investigate the phagocytic ability of neonates at birth.

Methods

The phagocytic ability of neutrophils and monocytes of 42 neonates was determined using the Phagotest flow cytometry method, that assesses the intake of E. Coli by phagocytes, in cord blood and in peripheral blood 3 days after birth. Fifteen healthy adults were included in the study as controls.

Results

The phagocytic ability of neutrophils in the cord blood of neonates was significantly reduced compared to adults. The 3^rd postnatal day the reduction of phagocytic ability of neutrophils was no longer significant compared to adults. The phagocytic ability of monocytes did not show any difference from that of adults either at birth or the 3^rd postnatal day.

Conclusions

Our findings indicate that the intake of E. Coli by phagocytes is impaired at birth in both preterm and full term neonates compared to adults. This defect is transient, with the phagocytic ability in neonates reaching that of the adults 3 days after birth.

Systematic review: neonatal meningitis in the developing world

Meningitis is more common in the neonatal period than any other time in life and is an important cause of morbidity and mortality globally. Despite the majority of the burden occurring in the developing world, the majority of the existing literature originates from wealthy countries. Mortality from neonatal meningitis in developing countries is estimated to be 40-58%, against 10% in developed countries. Important differences exist in the spectrum of pathogens isolated from cerebrospinal fluid cultures in developed versus developing countries. Briefly, while studies in developed countries have generally found Group B streptococcus (GBS), Escherichia coli and Listeria monocytogenes as important organisms, we describe how in the developing world results have varied; particularly regarding GBS, other Gram negatives (excluding E. coli), Listeria and Gram-positive organisms. The choice of empiric antibiotics should take into consideration local epidemiology if known, early versus late disease, resistance patterns and availability within resource constraints. Gaps in knowledge, the role of adjuvant therapies and future directions for research are explored.

International perspective on early-onset neonatal sepsis

Infections are a major cause of neonatal death in developing countries. High-quality information on the burden of early-onset neonatal sepsis and sepsis-related deaths is limited in most of these settings. Simple preventive and treatment strategies have the potential to save many newborns from sepsis-related death. Implementation of public health programs targeting newborn health will assist attainment of Millennium Development Goals of reduction in child mortality.

[Audit "Toys and incubators in neonatology"]

Owing to an increase in nosocomial septicaemias in the Neonatalogy department, we've judged it necessary to consider the role of items not linked to the nursing procedures, and nevertheless present in the incubators, as well as the hygiene techniques applied to them. In November 2007, we've made a longitudinal prospective study consisting in an observation audit during 3 successive days, observing every single incubator with a newborn baby. In each incubator, we've checked whether there were or not items that weren't required by the nursing activities, along with their characteristics and the hygiene procedures applied to them. We've inquired as well whether the parents and the nursing staff knew and applied the required hygiene procedures. In 13 among the 17 incubators under survey, at least one item not strictly required by the nursing procedures could be found. The number of toys in each incubator varied from seven to one. Among the 33 toys surveyed, 24 (73%) of them showed a score of maximum fluffiness (4 out of 4), and only 10 wore labels giving cleansing advice from the manufacturers. Without any record about the cleaning/disinfecting of the toys brought in hospital, we have observed that the parents were given varied advice about how to clean the toys at home before putting them in the incubators (only four parents had washed the toys in their washing machines at more than 30 degrees C). From the six samples under scrutiny, all the culture results were tested positive. In particular two of the soft toys sampled were found infected by a Pseudomonas oryzihabitans. These particular toys belonged to a baby who had been diagnosed with a septicaemia characterized by hemocultures positive to a P. oryzihabitans of a different strain. Our audit has been an efficient reminder that any item put in an incubator is a potential vector and reservoir of pathogen organisms. After a general feedback towards the department staff, the medical staff then prescribed to permanently ban all the items not strictly required by the nursing activities from all the incubators of the department.

The INIS Study. International Neonatal Immunotherapy Study: non-specific intravenous immunoglobulin therapy for suspected or proven neonatal sepsis: an international, placebo controlled, multicentre randomised trial

BACKGROUND

Sepsis is an important cause of neonatal death and perinatal brain damage, particularly in preterm infants. While effective antibiotic treatment is essential treatment for sepsis, resistance to antibiotics is increasing. Adjuvant therapies, such as intravenous immunoglobulin, therefore offer an important additional strategy. Three Cochrane systematic reviews of randomised controlled trials in nearly 6,000 patients suggest that non-specific, polyclonal intravenous immunoglobulin is safe and reduces sepsis by about 15% when used as prophylaxis but does not reduce mortality in this situation. When intravenous immunoglobulin is used in the acute treatment of neonatal sepsis, however, there is a suggestion that it may reduce mortality by 45%. However, the existing trials of treatment were small and lacked long-term follow-up data.This study will assess reliably whether treatment of neonatal sepsis with intravenous immunoglobulin reduces mortality and adverse neuro-developmental outcome.

METHODS AND DESIGN

A randomised, placebo controlled, double blind trial. Babies with suspected or proven neonatal sepsis will be randomised to receive intravenous immunoglobulin therapy or placebo.

ELIGIBILITY CRITERIA

Babies must be receiving antibiotics and have proven or suspected serious infection AND have at least one of the following: birthweight less than 1500 g OR evidence of infection in blood culture, cerebrospinal fluid or usually sterile body fluid OR be receiving respiratory support via an endotracheal tube AND there is substantial uncertainty that intravenous immunoglobulin is indicated.

EXCLUSION CRITERIA

Babies are excluded if intravenous immunoglobulin has already been given OR intravenous immunoglobulin is thought to be needed OR contra-indicated. Trial treatment: Babies will be given either 10 ml/kg of intravenous immunoglobulin or identical placebo solution over 4-6 hours, repeated 48 hours later.

PRIMARY OUTCOME

Mortality or major disability at two years, corrected for gestational age.

DATA COLLECTION

Data will be collected at discharge from hospital and at 2 years of age (corrected for gestation) using a parental questionnaire and a health status questionnaire completed during a face-to-face follow-up appointment with the child's paediatrician.

TRIAL REGISTRATION

Current Controlled Trials ISCRTN94984750.

Nosocomial Gram-positive bacterial infections in children: results of a 7 year study

BACKGROUND

The aim of the present paper was to determine the rate of culture-proven nosocomial infections and evaluate the episodes of nosocomial Gram-positive (GP) bacterial infections in pediatric patients.

METHODS

The data of children with positive culture, who were diagnosed as having nosocomial infection on the Centers for Disease Control and Prevention criteria, were examined and only the patients with nosocomial GP bacterial infections were included in the study.

RESULTS

Between January 1997 and January 2004 a total of 836 episodes of nosocomial GP bacterial infections were observed. The most frequently seen nosocomial GP bacterial infections were primary bloodstream infections (BSI; 43%), ventriculoperitoneal shunt infections (18%), and nosocomial pneumonias (11%). Coagulase-negative staphylococci (CONS; 46%) were the most common nosocomial GP bacteria isolated, followed by Staphylococcus aureus (33%). Methicillin resistance rates for CONS and S. aureus were 85% and 25.2%; respectively. The mortality rate was 4% of all children with nosocomial GP bacterial infections in the present study.

CONCLUSION

In the present patients primary BSI were the most common nosocomial GP bacterial infections and CONS were the most frequent GP pathogen isolated. Antimicrobial resistance in GP isolates is an increasing problem.

Perinatal infections and cerebral palsy

Infections of the mother, the intrauterine environment, the fetus, and the neonate can cause cerebral palsy through a variety of mechanisms. Each of these processes is reviewed. The recently proposed theory of cytokine-induced white matter brain injury and the systemic inflammatory response syndrome with multiple organ dysfunction syndrome is critically evaluated.

Late onset neonatal Gram-negative bacillary infection in Australia and New Zealand: 1992-2002

BACKGROUND

Late onset neonatal Gram-negative bacillary infection is a significant cause of morbidity and mortality.

OBJECTIVE

To determine the incidence and mortality from late onset Gram-negative bacillary infections in neonatal units.

METHODS

An 11-year longitudinal prospective surveillance study. Clinicians in 20 neonatal units in Australia and New Zealand collected data. Late onset sepsis was defined as clinical signs of infection starting more than 48 hours after birth, with laboratory evidence supporting sepsis and pure growth of a pathogen from blood and/or cerebrospinal fluid.

RESULTS

Overall, 702 of 3113 (22.5%) episodes of late onset sepsis in 681 infants were from Gram-negative bacilli. Overall mortality was 20.8% (142 of 681 infants) and significantly related to maturity, birth weight and infecting organism. Mortality was 25% for infants <30 weeks compared with 11.5% for infants > or =30 weeks gestation (P < 0.0001) and 24.2% for infants with birth weights <1500 g versus 12.7% if > or =1500 g (P < 0.0001). Infection by Pseudomonas aeruginosa was associated with 52.3% mortality (46 of 88 infants), significantly higher than the 13.7% to 23.8% fatality from other Gram-negative bacilli (P < 0.0001). During the surveillance, the late onset Gram-negative bacillary infection rate remained stable at 1.14 per 1000 live births (range 0.87-1.5). Similarly, mortality was unchanged, being 0.25 per 1000 live births (range 0.12-0.43).

CONCLUSIONS

Gram-negative bacilli remain important causes of late onset neonatal sepsis, especially among very low birth weight infants, and result in a high mortality, particularly with P. aeruginosa infections.

Population structure of group B streptococcus from a low-incidence region for invasive neonatal disease

The population structure of group B streptococcus (GBS) from a low-incidence region for invasive neonatal disease (Israel) was investigated using multilocus genotype data. The strain collection consisted of isolates from maternal carriage (n=104) and invasive neonatal disease (n=50), resolving into 46 sequence types. The most prevalent sequence types were ST-1 (17.5 %), ST-19 (10.4 %), ST-17 (9.7 %), ST-22 (8.4 %) and ST-23 (6.5 %). Serotype III was the most common, accounting for 29.2 % of the isolates. None of the serotypes was significantly associated with invasive neonatal disease. burst analysis resolved the 46 sequence types into seven lineages (clonal complexes), from which only lineage ST-17, expressing serotype III only, was significantly associated with invasive neonatal disease. Lineage ST-22 expressed mainly serotype II, and was significantly associated with carriage. The distribution of the various sequence types and lineages, and the association of lineage ST-17 with invasive disease, are consistent with the results of analyses from a global GBS isolate collection. These findings could imply that the global variation in disease incidence is independent of the circulating GBS populations, and may be more affected by other risk factors for invasive GBS disease, or by different prevention strategies.

Early onset neonatal meningitis in Australia and New Zealand, 1992-2002

OBJECTIVES

To study the epidemiology of early onset neonatal bacterial meningitis (EONBM) in Australasia.

DESIGN

Prospective surveillance study, 1992-2002, in 20 neonatal units in Australia and New Zealand. EONBM was defined as meningitis occurring within 48 hours of delivery.

RESULTS

There were 852 babies with early onset sepsis, of whom 78 (9.2%) had EONBM. The incidence of early onset group B streptococcal meningitis fell significantly from a peak of 0.24/1000 live births in 1993 to 0.03/1000 in 2002 (p trend = 0.002). There was no significant change over time in the incidence of Escherichia coli meningitis. The rate of EONBM in very low birthweight babies was 1.09/1000 compared with the rate in all infants of 0.11/1000. The overall rate of EONBM was 0.41/1000 in 1992 and 0.06 in 2001, but this trend was not significant (p trend = 0.07). Case-fatality rates for EONBM did not change significantly with time. Birth weight <1500 g (odds ratio (OR) 7.2 (95% confidence interval (CI) 4.8 to 10.9)) and Gram negative bacillary meningitis (OR 3.3 (95% CI 2.2 to 4.9)) were significant risk factors for mortality. Sixty two percent of the 129 babies who died from early onset sepsis or suspected sepsis did not have a lumbar puncture performed.

CONCLUSION

The incidence of early onset group B streptococcal meningitis has fallen, probably because of maternal intrapartum antibiotic prophylaxis, without a corresponding change in E. coli meningitis. Gram negative bacillary meningitis still carries a worse prognosis than meningitis with a Gram positive organism.

Escherichia coli: a growing problem in early onset neonatal sepsis

AIMS

To review the demographic characteristics, antecedents and outcome for early neonatal Escherichia coli sepsis. Secondary aims were to identify antenatal antibiotic use and to review the antimicrobial susceptibility.

METHODS

A retrospective chart review was performed for all infants with a positive culture for E. coli from either blood or CSF samples obtained between January 1998 and October 2002.

RESULTS

Nineteen liveborn infants with early onset sepsis and one stillborn baby with a positive maternal blood culture for E. coli were identified. Pregnancy complications included multiple pregnancy in five (25%), preterm rupture of membranes 10 (50%) and maternal urinary tract infection in five (25%). Eighteen of the cases were born preterm and two at term. The mortality was 8/20 (40%), and for nine cases with developmental outcome data available, 67% were within normal limits and 33% were abnormal. Of the 20 E. coli isolates 11 (55%) were resistant to amoxycillin and 1 (5%) was resistant to gentamicin.

CONCLUSIONS

Infants with early onset E. coli sepsis had a poor outcome with high mortality and a third of the survivors manifesting neurodevelopmental impairment. Although amoxycillin resistance is common, there is a low prevalence of gentamicin resistance in local isolates.

Does human milk reduce infection rates in preterm infants? A systematic review

One of the reasons for advocating human milk (HM) feeding for preterm infants is the belief that this provides the infant with a degree of protection from infection. Providing fresh HM for such infants is challenging for mothers and staff, and consequently it is important that its benefits are rigorously evaluated. Therefore a systematic review was undertaken to assess all publications concerned with human milk feeding and infection in very low birth weight (VLBW) preterm infants. Nine studies--six cohort and three randomised controlled trials (RCT)--were assessed using predefined criteria. Methodological problems included poor study design, inadequate sample size, failure to adjust for confounding variables, and inadequate definitions of HM feeding and outcome measures. In conclusion, the advantage of HM in preventing infection in preterm, (VLBW) infants is not proven by the existing studies. Recommendations are made regarding the methodology required for further study of this important topic.

Staphylococcus aureus infections in Australasian neonatal nurseries

OBJECTIVE

To study the incidence and outcome of systemic infections with methicillin sensitive (MSSA) and methicillin resistant Staphylococcus aureus (MRSA) infections in Australasian neonatal nurseries.

METHODS

Prospective longitudinal study of systemic infections (clinical sepsis plus positive cultures of blood and/or cerebrospinal fluid) in 17 Australasian neonatal nurseries.

RESULTS

The incidence of early onset sepsis with S aureus, mainly MSSA, was 19 cases per 244 718 live births or 0.08 per 1000. From 1992 to 1994, MRSA infections caused only 8% of staphylococcal infections. From 1995 to 1998, there was an outbreak of MRSA infection, in two Melbourne hospitals. The outbreak resolved, after the use of topical mupirocin and improved handwashing. Babies with MRSA sepsis were significantly smaller than babies with MSSA sepsis (mean birth weight 1093 v 1617 g) and more preterm (mean gestation 27.5 v 30.3 weeks). The mortality of MRSA sepsis was 24.6% compared with 9.9% for MSSA infections. The mortality of early onset MSSA sepsis, however, was 39% (seven of 18) compared with 7.3% of late onset MSSA infection presenting more than two days after birth.

CONCLUSIONS

S aureus is a rare but important cause of early onset sepsis. Late onset MRSA infections carried a higher mortality than late onset MSSA infections, but babies with early onset MSSA sepsis had a particularly high mortality.

Ten-year study on the effect of intrapartum antibiotic prophylaxis on early onset group B streptococcal and Escherichia coli neonatal sepsis in Australasia

BACKGROUND

Intrapartum antibiotics have reduced the incidence of neonatal early onset (EO) group B streptococcal (GBS) disease. Some surveillance data suggest that this success may be at the cost of increasing rates of non-GBS infection, especially in premature neonates.

OBJECTIVE

To examine rates of EOGBS infection and EO Escherichia coli neonatal sepsis in Australasia.

METHODOLOGY

Analysis of trends in EO (<48 h age) GBS and E. coli sepsis from longitudinal prospective surveillance data collected from representative tertiary obstetric hospitals in each state of Australia and selected centers in New Zealand during a 10-year period from 1992 through 2001. Statistical analysis used Poisson regression.

RESULTS

206 GBS and 96 E. coli cases occurred in 298,319 live births during the study period. The EOGBS sepsis rate fell from a peak of 1.43/1000 live births in 1993 to 0.25/1000 in 2001 (P < 0.001). The overall EO E. coli sepsis rate was 0.32/1000. In babies with birth weight <1500 g, it was 6.20/1000. There was an overall trend to decreasing EO E. coli sepsis (P = 0.07), and there was no significant change in E. coli sepsis in babies <1500 g (P = 0.60). Sixty-nine percent of E. coli cases occurred in the <1500 g cohort; the case fatality rate in this group was 50%. The overall case fatality rate from E. coli sepsis was 36%, and this rate remained stable during the study period (P = 0.47).

CONCLUSIONS

The increasing use of intrapartum antibiotics produced a steady decline in EOGBS disease in Australasia. There was also a trend to decreasing EO E. coli sepsis in all babies, and the rate in very low birth weight infants remained stable.

Late-onset infection and the role of antibiotic prescribing policies

PURPOSE OF REVIEW

Late-onset infection is a significant cause of morbidity and mortality in low-birth-weight and premature infants. Empirical antibiotic treatment is used as infants can deteriorate rapidly without treatment. Current data on the epidemiology of late-onset infection, the types of antibiotics used, duration of antibiotic use, and antibiotic prescribing policies are reviewed.

RECENT FINDINGS

Epidemiological data on late-onset sepsis is dominated by information concerning developed countries; large prospective data collections have been set up in many such countries. Recent data indicate that late-onset sepsis occurs in one-fifth of very-low-birth-weight infants. There are increasing concerns regarding antibiotic resistance. Antibiotic regimens that do not include third-generation cephalosporins produce less resistance. Strategies of antibiotic rotation have not been documented as producing a marked effect on the development of resistant micro-organisms, but there is a lack of randomized trials. Recommendations for preventing the spread of vancomycin-resistant enterococci, produced by the Hospital Infection Control Practices Advisory Committee, have been shown to be effective in a number of situations. Recent reports have documented the success of multidisciplinary, systems-orientated approaches for reducing neonatal nosocomial infection.

SUMMARY

Antibiotic prescribing policies have an important role to play in the treatment of late-onset neonatal infection. There is enough evidence to state that narrow-spectrum antibiotics should be used wherever possible and that potent broad-spectrum antibiotics should be kept in reserve. Ongoing prospective surveillance of infection rates, micro-organisms, resistance and antibiotic use is essential.

Management of septic shock in childhood

OBJECTIVE

The object of this review is to discuss the recognition and treatment of septic shock in children based on principles of resuscitation, antibiotic use and recent therapeutic advances.

METHODS

A comprehensive literature search combining these

METHODS

on-line searches of Ovid, PubMed, and Medline; hand searches of 25 international journals; a trawl of 26 textbooks; searches of reference lists of pertinent articles; and scans of abstracts of recent international meetings. Various national and international units were contacted with regard to current research therapeutic strategies, both published and unpublished.

CONCLUSIONS

Septic shock remains a leading cause of morbidity and mortality in children. Early administration of empirical antibiotic therapy reduces mortality. The keystone of resuscitation is aggressive volume replacement. Adjunctive therapies to modulate the inflammatory response may further enhance outcome, but do not replace principles of resuscitation.

Neonatal meningitis

Twelve years ago an annotation was published in Archives of Disease in Childhood regarding the antibiotic treatment of suspected neonatal meningitis. The authors recommended the use of cephalosporins rather than chloramphenicol and advocated intraventricular aminoglycoside treatment in selected cases. They noted the absence of clinical trials with third generation cephalosporins that showed an improvement in mortality or neurological outcome.