To tap or not to tap: high likelihood of meningitis without sepsis among very low birth weight infants

Epidemiology, microbiology and antibiotic treatment of bacterial and fungal meningitis among very preterm infants in China: a cross-sectional study

OBJECTIVE

Neonatal meningitis significantly contributes to neonatal morbidity and mortality, yet large-scale epidemiological data in developing countries, particularly among very preterm infants (VPIs), remain sparse. This study aimed to describe the epidemiology of meningitis among VPIs in China.

DESIGN

Cross-sectional study using the Chinese Neonatal Network database from 2019 to 2021.

SETTING

79 tertiary neonatal intensive care units in China.

PATIENTS

Infants with gestational age <32 weeks or birth weight <1500 g.

MAIN OUTCOME MEASURES

Incidence, pathogen distribution, antimicrobial use and outcomes of bacterial and fungal meningitis.

RESULTS

Of 31 915 VPIs admitted, 122 (0.38%) infants were diagnosed with culture-confirmed meningitis, with 14 (11.5%) being early-onset (≤6 days of age) and 108 (88.5%) being late-onset (>6 days of age). The overall in-hospital mortality was 18.0% (22/122). A total of 127 pathogens were identified, among which 63.8% (81/127) were Gram-negative bacteria, 24.4% (31/127) were Gram-positive bacteria and 11.8% (15/127) were fungi. In terms of empirical therapy (on the day of the first lumbar puncture), the most commonly used antibiotic was meropenem (54.9%, 67/122). For definitive therapy (on the sixth day following the first lumbar puncture, 86 cases with available antibiotic data), meropenem (60.3%, 35/58) and vancomycin (57.1%, 16/28) were the most used antibiotics for Gram-negative and Gram-positive bacterial meningitis, respectively. 44% of infants with Gram-positive bacterial meningitis and 52% with Gram-negative bacterial meningitis received antibiotics for more than 3 weeks.

CONCLUSION

0.38% of VPIs in Chinese neonatal intensive care units were diagnosed with meningitis, experiencing significant mortality and inappropriate antibiotic therapy. Gram-negative bacteria were the predominant pathogens, with fungi emerging as a significant cause.

Epidemiology and outcomes of bacterial meningitis in the neonatal intensive care unit

OBJECTIVE

Examine pathogen distribution, antibiotic resistance patterns, and hospital outcomes of infants with bacterial meningitis in neonatal intensive care units (NICUs) in the US from 2013-2018.

STUDY DESIGN

Infants were divided into 2 groups based on age at the time of meningitis: early-onset (0-3 days) and late-onset (>3 days). We compared demographics, clinical characteristics, epidemiology, hospital outcomes, distribution of organisms and resistance, and blood culture timing relative to cerebrospinal fluid culture.

RESULTS

From 345 NICUs, 659 infants were diagnosed with bacterial meningitis. The cumulative incidence was 1.1-1.3 cases/1000 NICU discharges. Median gestational age was 33 weeks, median birth weight was 1910 grams, 12% failed hearing screening, and 9% died prior to discharge. Of 141 cases of E. coli meningitis, 53% were resistant to ampicillin.

CONCLUSIONS

Significant morbidities occur in infants with culture-proven meningitis in NICUs. Culture and subsequent discernment of sensitivity are crucial to guide definitive therapy.

Characterization of Clinical Presentation, Etiology, and Antibiotic Sensitivity Patterns in Neonatal Septicemia: A Comprehensive Analysis of Bacterial Isolates

BACKGROUND

Neonatal septicemia remains a significant healthcare challenge, particularly in resource-limited settings, with both early-onset neonatal septicemia (EONS) and late-onset neonatal septicemia (LONS) presentations contributing to morbidity and mortality. This study aimed to characterize the clinico-etiological profile and antibiotic susceptibility patterns of neonatal septicemia in a tertiary care setting in north India.

METHODOLOGY

An analytical cross-sectional study was conducted from March 2021 to February 2022, encompassing neonates admitted to the Department of Pediatrics with suspected neonatal septicemia, confirmed by positive blood cultures.

RESULTS

A total of 96 neonates were included, predominantly male (71.9%). Gram-negative bacteria constituted 61.6% of isolates, and the most common organism isolated was non-lactose fermenter group (38.4%) followed by coagulase-negative staphylococci (CoNS) (33.4%). Non-lactose fermenter group bacteria were prominent in EONS cases (44.6%), while CoNS predominated in LONS cases (51.6%). Birthplace, birth weight, and perinatal score were significantly associated with both EONS and LONS. Linezolid exhibited high efficacy against gram-positive bacteria, while ciprofloxacin and meropenem demonstrated effectiveness against various gram-negative pathogens. Methicillin-resistant Staphylococcus aureus (MRSA) strains exhibited resistance to all the antibiotics used in the study except for linezolid.

CONCLUSION

These findings underscore the importance of tailored empirical therapy guided by local epidemiological data to optimize clinical outcomes and mitigate antimicrobial resistance.

Diagnostic Utility of Cerebrospinal Fluid White Blood Cell Components for the Identification of Bacterial Meningitis in Infants

BACKGROUND

To evaluate the diagnostic and predictive utility of cerebrospinal fluid (CSF) white blood cell (WBC) components in the diagnosis of bacterial meningitis in infants discharged from the neonatal intensive care unit (NICU).

METHODS

We identified a cohort of infants discharged from a Pediatrix NICU between 1997 and 2020 who did not have an immunodeficiency, had at least 1 CSF culture collected within the first 120 days of life, and at least 1 CSF laboratory specimen obtained on the day of culture collection. We only included an infant's first CSF culture and excluded cultures from CSF reservoirs and those growing contaminants or nonbacterial organisms. We examined the utility of CSF WBC components to diagnose or predict bacterial meningitis by calculating sensitivity, specificity, positive and negative predictive values, likelihood ratios, and area under the receiver operating curve (AUC) at different cutoff values for each parameter. We performed subgroup analysis excluding infants treated with antibiotics the day before CSF culture collection.

RESULTS

Of the 20 756 infants that met the study inclusion criteria, 320 (2%) were diagnosed with bacterial meningitis. We found (AUC [95% CI]) CSF WBC count (0.76 [0.73-0.79]), CSF neutrophil count (0.74 [0.70-0.78]), and CSF neutrophil percent (0.71 [0.67-0.75]) had the highest predictive values for bacterial meningitis, even when excluding infants with early antibiotic administration.

CONCLUSIONS

No single clinical prediction rule had the optimal discriminatory power for predicting culture-proven bacterial meningitis, and clinicians should be cautious when interpreting CSF WBC parameters in infants with suspected meningitis.

Lumbar Puncture and Meningitis in Infants with Proven Early- or Late-Onset Sepsis: An Italian Prospective Multicenter Observational Study

Background: To evaluate the rates of lumbar puncture (LP) in infants with culture-proven sepsis. Study design: We prospectively enrolled 400 infants with early- or late-onset sepsis due to Group B streptococcus (GBS) or Eschericha coli, diagnosed within 90 days of life. Rates of LP and potential variables associated with LP performance were evaluated. Moreover, cerebrospinal fluid (CSF) characteristics and results of the molecular analysis were investigated. Results: LP was performed in 228/400 (57.0%) infants; 123/228 LPs (53.9%) were performed after antibiotic initiation, hampering the ability to identify the pathogen in the CSF culture. However, polymerase chain reaction increased the probability of positive results of CSF analysis compared to microbiological culture (28/79, 35.4% vs. 14/79, 17.7%, p = 0.001). Severe clinical presentation and GBS infection were associated with higher LP rates. The rate of meningitis was 28.5% (65/228). Conclusions: Rates of LP are low in culture-proven neonatal sepsis and antibiotics are frequently given before LP is carried out. Thus meningitis may be underestimated, and the chances of giving an effective therapy to the newborn are reduced. LP should be performed before the start of antibiotics when there is a clinical suspicion of infection.

Late-Onset Sepsis Mortality among Preterm Infants: Beyond Time to First Antibiotics

Objective: To investigate the impact of timing, in vitro activity and appropriateness of empirical antimicrobials on the outcome of late-onset sepsis among preterm very low birth weight infants that are at high risk of developing meningitis. Study design: This retrospective study included 83 LOS episodes in 73 very low birth weight infants born at ≤32 weeks' gestation with positive blood and/or cerebrospinal fluid culture or polymerase chain reaction at >72 h of age. To define the appropriateness of empirical antimicrobials we considered both their in vitro activity and their ideal delivery through the blood-brain barrier when meningitis was confirmed or not ruled out through a lumbar puncture. The primary outcome was sepsis-related mortality. The secondary outcome was the development of brain lesions. Timing, in vitro activity and appropriateness of empirical antimicrobials, were compared between fatal and non-fatal episodes. Uni- and multi-variable analyses were carried out for the primary outcome. Results: Time to antibiotics and in vitro activity of empirical antimicrobials were similar between fatal and non-fatal cases. By contrast, empirical antimicrobials were appropriate in a lower proportion of fatal episodes of late-onset sepsis (4/17, 24%) compared to non-fatal episodes (39/66, 59%). After adjusting for Gram-negative vs. Gram-positive pathogen and for other supportive measures (time to volume administration), inappropriate empirical antimicrobials remained associated with mortality (aOR, 10.3; 95% CI, 1.4-76.8, p = 0.023), while timing to first antibiotics was not (aOR 0.9; 95% CI, 0.7-1.2, p = 0.408; AUC = 0.88). The association between appropriate antimicrobials and brain sequelae was also significant (p = 0.024). Conclusions: The risk of sepsis-related mortality and brain sequelae in preterm very low birth weight infants is significantly associated with the appropriateness (rather than the timing and the in vitro activity) of empirical antimicrobials. Until meningitis is ruled out through lumbar puncture, septic very low birth weight infants at high risk of mortality should receive empiric antimicrobials with high delivery through the blood-brain barrier.

Incidence of and Neurodevelopmental Outcomes After Late-Onset Meningitis Among Children Born Extremely Preterm

Importance

Late-onset meningitis (LOM) has been associated with adverse neurodevelopmental outcomes in children born extremely preterm.

Objective

To report the incidence of LOM during birth hospitalization and neurodevelopmental outcomes at 18 to 26 months' corrected age.

Design, Setting, and Participants

This cohort study is a secondary analysis of a multicenter prospective cohort of children born at 22 to 26 weeks' gestation between 2003 and 2017 with follow-up from 2004 to 2021. The study was conducted at 25 Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network centers.

Exposures

Culture-confirmed LOM.

Main Outcomes and Measures

Incidence and microbiology of LOM (2003-2017); lumbar puncture (LP) performance in late-onset sepsis (LOS) evaluations (2011-2017); composite outcome of death or neurodevelopmental impairment (NDI; 2004-2021).

Results

Among 13 372 infants (median [IQR] gestational age, 25.4 [24.4-26.1] weeks; 6864 [51%] boys), LOM was diagnosed in 167 (1%); LOS without LOM in 4564 (34%); and neither LOS nor LOM in 8641 (65%). The observed incidence of LOM decreased from 2% (95% CI, 1%-3%) in 2003 to 0.4% (95% CI, 0.7%-1.0%) in 2017 (P < .001). LP performance in LOS evaluations decreased from 36% (95% CI, 33%-40%) in 2011 to 24% (95% CI, 21%-27%) in 2017 (P < .001). Among infants with culture-confirmed LOS, LP performance decreased from 58% (95% CI, 51%-65%) to 45% (95% CI, 38%-51%; P = .008). LP performance varied by center among all LOS evaluations (10%-59%, P < .001) and among those with culture-confirmed LOS (23%-79%, P < .001). LOM occurred in the absence of concurrent LOS in 27 of 167 cases (16%). The most common LOM isolates were coagulase-negative Staphylococcus (98 [59%]), Candida albicans (38 [23%]), and Escherichia coli (27 [16%]). Death or NDI occurred in 22 of 46 children (48%) with LOM due to coagulase-negative Staphylococcus, 43 of 67 (64%) due to all other bacterial pathogens, and 26 of 33 (79%) due to fungal pathogens. The adjusted relative risk of death or NDI was increased among children with LOM (aOR, 1.53; 95% CI, 1.04-2.25) and among those with LOS without LOM (aOR, 1.41; 95% CI, 1.29-1.54) compared with children with neither infection.

Conclusions and Relevance

In this cohort study, LP was performed with decreasing frequency, and the observed incidence of LOM also decreased. Both LOM and LOS were associated with increased risk of death or NDI; risk varied by LOM pathogen. The full association of LOM with outcomes of children born extremely preterm may be underestimated by current diagnostic practices.

Neonatal infections: Insights from a multicenter longitudinal research collaborative

For more than 30 years, the Neonatal Research Network (NRN) has conducted studies addressing the epidemiology of neonatal infections, including incidence, microbiology, maternal and neonatal risk factors, associated clinical findings, and outcomes. These studies have provided clinicians and policymakers critical data needed to inform national guidance for infection risk assessment and support daily practice. Further, NRN studies have prompted research into optimal approaches to infection diagnosis, treatment, and antimicrobial stewardship. In this article, we summarize the key findings of NRN infection-related studies, with an emphasis on those published in 2000 or later.

Updates in Late-Onset Sepsis: Risk Assessment, Therapy, and Outcomes

Neonatal late-onset sepsis (LOS) continues to threaten morbidity and mortality in the NICU and poses ongoing diagnostic and therapeutic challenges. Early recognition of clinical signs, rapid evaluation, and prompt initiation of treatment are critical to prevent life-threatening deterioration. Preterm infants-born at ever-decreasing gestational ages-are at particularly high risk for life-long morbidities and death. This changing NICU population necessitates continual reassessments of diagnostic and preventive measures and evidence-based treatment for LOS. The clinical presentation of LOS is varied and nonspecific. Despite ongoing research, reliable, specific laboratory biomarkers facilitating early diagnosis are lacking. These limitations drive an ongoing practice of liberal initiation of empiric antibiotics among infants with suspected LOS. Subsequent promotion of multidrug-resistant microorganisms threatens the future of antimicrobial therapy and puts preterm and chronically ill infants at even higher risk of nosocomial infection. Efforts to identify adjunctive therapies counteracting sepsis-driven hyperinflammation and sepsis-related functional immunosuppression are ongoing. However, most approaches have either failed to improve LOS prognosis or are not yet ready for clinical application. This article provides an overview of the epidemiology, risk factors, diagnostic tools, and treatment options of LOS in the context of increasing numbers of extremely preterm infants. It addresses the question of whether LOS could be identified earlier and more precisely to allow for earlier and more targeted therapy and discusses rational approaches to antibiotic therapy to avoid overuse. Finally, this review elucidates the necessity of long-term follow-up of infants with a history of LOS.

Quantitative proteomic analysis of cerebrospinal fluid reveals CD163, A2M and full-length APP as potential diagnostic biomarkers of paediatric bacterial meningitis

Background

Bacterial meningitis (BM) is a life-threatening infectious disease of the central nervous system in infants and children. To date, no diagnostic methods for the early and precise diagnosis of paediatric BM have been developed.

Methods

A label-free cerebrospinal fluid (CSF) quantitative proteomic analysis of 8 patients with confirmed or suspected BM, 9 patients with confirmed or suspected viral meningitis (VM) and 6 non-CNS-infected hospital patients was performed via high-resolution LC–MS/MS.

Results

Our CSF proteomic analysis allowed the identification of critical differences between the BM and non-BM groups. Compared to the proteomes of the non-BM groups, the proteome of the paediatric BM group was characterized by upregulation of complement and coagulation cascades, regulation of IGF transport, uptake by IGF-binding proteins and acute inflammatory response, downregulation of developmental growth, and metabolism of carbohydrates. Moreover, the levels of CD163, A2M and full-length APP in CSF showed excellent diagnostic performance for paediatric BM, with AUC values of 0.911 (95% CI: 0.839–0.984), 0.908 (95% CI: 0.816–1.000) and 0.944 (95% CI: 0.86, 1.000), respectively. Among them, A2M and full-length APP are reported here for the first time as potential diagnostic biomarkers of BM. The findings imply that peptidase regulator activity plays an important role in BM and provide potential novel targets for precision medicine in paediatric BM.

Conclusions

CD163, A2M and full-length APP are validated as potential diagnostic biomarkers of paediatric BM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12953-022-00191-5.

Cost Savings of Mother's Own Milk for Very Low Birth Weight Infants in the Neonatal Intensive Care Unit

OBJECTIVE

The study aim was to determine the relationship between hospitalization costs and mother's own milk (MOM) dose for very low birth weight (VLBW; < 1500 g) infants during the initial neonatal intensive care unit (NICU) stay. Additionally, because MOM intake during the NICU hospitalization is associated with a reduction in the risk of late-onset sepsis, necrotizing enterocolitis (NEC), and bronchopulmonary dysplasia (BPD), we aimed to quantify the incremental cost of these potentially preventable complications of prematurity.

METHODS

The study included 430 VLBW infants enrolled in the Longitudinal Outcomes of Very Low Birthweight Infants Exposed to Mothers' Own Milk prospective cohort study between 2008 and 2012 at Rush University Medical Center in Chicago, IL, USA. NICU hospitalization costs included hospital, feeding, and physician costs. The average marginal effect of MOM dose and prematurity-related complications known to be reduced by MOM intake on NICU hospitalization costs were estimated using generalized linear regression.

RESULTS

The mean NICU hospitalization cost was $190,586 (standard deviation $119,235). The marginal cost of sepsis was $27,890 (95% confidence interval [CI] $2934-$52,646), of NEC was $46,103 (95% CI $16,829-$75,377), and of BPD was $41,976 (95% CI $24,660-59,292). The cumulative proportion of MOM during the NICU hospitalization was not significantly associated with cost.

CONCLUSIONS

A reduction in the incidence of complications that are potentially preventable with MOM intake has significant cost implications. Hospitals should prioritize investments in initiatives to support MOM feedings in the NICU.

Group B Streptococcal Neonatal Meningitis

Neonatal bacterial meningitis is a devastating disease, associated with high mortality and neurological disability, in both developed and developing countries. Streptococcus agalactiae, commonly referred to as group B Streptococcus (GBS), remains the most common bacterial cause of meningitis among infants younger than 90 days. Maternal colonization with GBS in the gastrointestinal and/or genitourinary tracts is the primary risk factor for neonatal invasive disease. Despite prophylactic intrapartum antibiotic administration to colonized women and improved neonatal intensive care, the incidence and morbidity associated with GBS meningitis have not declined since the 1970s. Among meningitis survivors, a significant number suffer from complex neurological or neuropsychiatric sequelae, implying that the pathophysiology and pathogenic mechanisms leading to brain injury and devastating outcomes are not yet fully understood. It is imperative to develop new therapeutic and neuroprotective approaches aiming at protecting the developing brain. In this review, we provide updated clinical information regarding the understanding of neonatal GBS meningitis, including epidemiology, diagnosis, management, and human evidence of the disease's underlying mechanisms. Finally, we explore the experimental models used to study GBS meningitis and discuss their clinical and physiologic relevance to the complexities of human disease.

Short information: Bacterial meningitis in very low birthweight infants in Korea from 2013-2016

BACKGROUND

Neonatal bacterial meningitis (BM) has an incidence of 0.2-0.4 per 1,000 births and a mortality rate of 20-25%. Data from the Korean Neonatal Network (KNN) were evaluated to study the incidence, mortality, and risk factors associated with BM in very-low-birthweight (VLBW; <1,500 g) infants.

METHODS

We analyzed KNN data from 2013-2016 collected from 70 neonatal units.

RESULTS

The incidence of BM in VLBW infants was 40 out of 8,263 (0.5%). The 40 infants with BM had a mean gestational age of 27.1 ± 2.0 weeks and a mean birthweight of 1,036.8 ± 220.0 g. Mean age at diagnosis was 51.5 ± 38.3 days (range, 1-171). Infants with BM were divided into two groups: Group 1 (onset age ≤ 28 days) and Group 2 (onset age > 28 days). Coagulase-negative Staphylococcus (CONS) was the most common pathogen underlying meningitis in 11 of 40 cases (28%). BM co-occurred with bacteremia in 14 of 40) of cases (35%); bacteremia was significantly more common in Group 1 than Group 2 (P < 0.05). Seizure and intraventricular hemorrhage (≥grade 3) were significantly more prevalent in Group 2 than Group 1 (P < 0.05). The mortality rate of infants with BM was 4 out of 40 (10%), which was significantly lower than that of VLBW infants without BM (1,152/8,223, [14%]; P < 0.05).

CONCLUSIONS

The incidence of BM in VLBW infants was high, but the mortality rate was low. CONS was the most common pathogen of BM in VLBW infants.

Is Lumbar Puncture Avoidable in Low-Risk Neonates with Suspected Sepsis?

OBJECTIVE

Performing lumbar punctures (LP) in all clinically suspected neonatal sepsis, as per current recommendations, results in many "negative" LPs. LPs are not without their own risks. With the intention of minimizing unnecessary LPs among neonates, we aimed to identify a subgroup at extremely low risk of developing possible meningitis so that an LP could be safely avoided in it.

STUDY DESIGN

This was a prospective, observational, and cross-sectional study in a level III neonatal unit. We included 300 episodes, in which LP was performed for suspected sepsis. We recorded a comprehensive set of clinico-demographic variables, laboratory parameters, sickness score, organ dysfunction score, and organ localization and studied association of these factors with "definite (culture positive) or possible meningitis." "Possible" meningitis was defined with liberal criteria, intending not to miss any meningitis. A subgroup without a single factor associated with "definite or possible meningitis" was analyzed for incidence of meningitis.

RESULTS

There were 121 episodes of "definite or possible meningitis" among 300 episodes of sepsis. On unadjusted analysis, apnea, irritability, high-pitched cry, seizures, neutrophilia, high C-reactive protein (CRP), score for acute neonatal physiology and perinatal extension II (SNAPPE-II), urine output, and leukomalacia were associated with "definite or possible" meningitis (p < 0.05). On multivariate analysis, no apneas, no neutrophilia, and normal CRP were independently associated with "no definite or possible meningitis." Nevertheless, the subgroup that had a combination of no apneas, no neutrophilia, and normal CRP (n = 118) had a 29% probability of "definite or possible meningitis."

CONCLUSION

The lowest risk subgroup had a 29% chance of having "definite or possible" meningitis. There is no subgroup that we could identify among neonates with suspected sepsis, in which it is safe to avoid an LP.

KEY POINTS

· LP are performed in all cases of late onset neonatal sepsis.. · Previous authors unsuccessfully tried to identify high-risk groups for performing LP.. · We were unable to identify an extremely low-risk group in which LP could be safely avoided..

Epidemiology and Outcomes of Hospitalizations Due to Hepatocellular Carcinoma

Background Hepatocellular Carcinoma (HCC) is a severe complication of cirrhosis and the incidence of HCC has been increasing in the United States (US). We aim to describe the trends, characteristics, and outcomes of hospitalizations due to HCC across the last decade. Methods We derived a study cohort from the Nationwide Inpatient Sample (NIS) for the years 2008-2017. Adult hospitalizations due to HCC were identified using the International Classification of Diseases (9th/10th Editions) Clinical Modification diagnosis codes (ICD-9-CM/ICD-10-CM). Comorbidities were also identified by ICD-9/10-CM codes and Elixhauser Comorbidity Software (Agency for Healthcare Research and Quality, Rockville, Maryland, US). Our primary outcomes were in-hospital mortality and discharge to the facility. We then utilized the Cochran-Armitage trend test and multivariable survey logistic regression models to analyze the trends, outcomes, and predictors. Results A total of 155,436 adult hospitalizations occurred due to HCC from 2008-2017. The number of hospitalizations with HCC decreased from 16,754 in 2008 to 14,715 in 2017. Additionally, trends of in-hospital mortality declined over the study period but discharge to facilities remained stable. Furthermore, in multivariable regression analysis, predictors of increased mortality in HCC patients were advanced age (OR 1.1; 95%CI 1.0-1.2; p< 0.0001), African American (OR 1.3; 95%CI 1.1-1.4;p< 0.001), Rural/ non-teaching hospitals (OR 2.7; 95%CI 2.4-3.3; p< 0.001), uninsured (OR 1.9; CI 1.6-2.2; p< 0.0001) and complications like septicemia and pneumonia as well as comorbidities such as hypertension, diabetes mellitus, and renal failure. We observed similar trends in discharge to facilities. Conclusions In this nationally representative study, we observed a decrease in hospitalizations of patients with HCC along with in-hospital mortality; however, discharge to facilities remained stable over the last decade. We also identified multiple predictors significantly associated with increased mortality, some of which are potentially modifiable and can be points of interest for future studies.

Complete Genome Sequence of the Neonatal Meningitis Escherichia coli Serotype O18:K1 Strain NMEC15

Neonatal meningitis Escherichia coli (NMEC) is the second leading cause of sepsis and meningitis in neonates worldwide. Here, we report the genome sequence of NMEC15, belonging to serotype O18:K1, isolated from the cerebrospinal fluid (CSF) of an infant with neonatal bacterial meningitis (NBM) in the Netherlands.

Association of Infection in Neonates and Long-Term Neurodevelopmental Outcome

Perinatal and neonatal infection and associated inflammatory response may adversely affect brain development and lead to neurodevelopmental impairment. Factors that predict the risk of infection and subsequent adverse outcomes have been identified but substantial gaps remain in identifying mechanisms and interventions that can alter outcomes. This article describes the current epidemiology of neonatal sepsis, the pathogenesis of brain injury with sepsis, and the reported long-term neurodevelopment outcomes among survivors.

A sequential guide to identify neonates with low bacterial meningitis risk: a multicenter study

Objective

To derive and validate a predictive algorithm integrating clinical and laboratory parameters to stratify a full‐term neonate's risk level of having bacterial meningitis (BM).

Methods

A multicentered dataset was categorized into derivation (689 full‐term neonates aged ≤28 days with a lumbar puncture [LP]) and external validation (383 neonates) datasets. A sequential algorithm with risk stratification for neonatal BM was constructed.

Results

In the derivation dataset, 102 neonates had BM (14.8%). Using stepwise regression analysis, fever, infection source absence, neurological manifestation, C‐reactive protein (CRP), and procalcitonin were selected as optimal predictive sets for neonatal BM and introduced to a sequential algorithm. Based on the algorithm, 96.1% of BM cases (98 of 102) were identified, and 50.7% of the neonates (349 of 689) were classified as low risk. The algorithm’s sensitivity and negative predictive value (NPV) in identifying neonates at low risk of BM were 96.2% (95% CI 91.7%–98.9%) and 98.9% (95% CI 97.6%–99.6%), respectively. In the validation dataset, sensitivity and NPV were 95.9% (95% CI 91.0%–100%) and 98.8% (95% CI 97.7%–100%).

Interpretation

The sequential algorithm can risk stratify neonates for BM with excellent predictive performance and prove helpful to clinicians in LP‐related decision‐making.

Impact of bundle implementation on the incidence of peri/intraventricular hemorrhage among preterm infants: a pre-post interventional study

BACKGROUND

Peri/intraventricular hemorrhage (PIVH) is a frequent cause of death and morbidity among preterm infants. Few studies have addressed the use of bundles for preventing PIVH.

OBJECTIVE

To evaluate the efficacy of a bundle of interventions designed to decrease the incidence of intraventricular hemorrhage at hospital discharge among preterm infants.

DESIGN AND SETTING

Pre-post interventional study with retrospective and prospective data collection performed before and after bundle implementation in the neonatal intensive care unit of a university hospital.

METHODS

Infants with gestational age < 32 weeks without malformations, who survived > 6 days were included. The bundle consisted of the following actions during the first 72 hours of life: maintenance of head in neutral position with the body in supine position, minimal handling, including delay of lumbar puncture until after 72 hours and absence of respiratory therapy maneuvers. Cranial ultrasound was performed on days 3, 7 and 28, or later if needed. The effect of the bundle was analyzed through logistic regression and results were adjusted for confounding variables.

RESULTS

167 infants met the inclusion criteria; 146 (87%) were analyzed. Bundle implementation was associated with decreased chances of PIVH at hospital discharge (odds ratio 0.29; 95% confidence interval 0.13-0.65). Cerebrospinal fluid collection within the first 72 hours increased the odds of PIVH of any grade during the hospital stay fourfold, after adjustment for all variables included in the model.

CONCLUSION

Implementation of a bundle of interventions to avoid intraventricular hemorrhage was effective for decreasing the incidence of all grades of PIVH in preterm infants.

Infection control and other stewardship strategies in late onset sepsis, necrotizing enterocolitis, and localized infection in the neonatal intensive care unit

Suspected or proven late onset sepsis, necrotizing enterocolitis, urinary tract infections, and ventilator associated pneumonia occurring after the first postnatal days contribute significantly to the total antibiotic exposures in neonatal intensive care units. The variability in definitions and diagnostic criteria in these conditions lead to unnecessary antibiotic use. The length of treatment and choice of antimicrobial agents for presumed and proven episodes also vary among centers due to a lack of supportive evidence and guidelines. Implementation of robust antibiotic stewardship programs can encourage compliance with appropriate dosages and narrow-spectrum regimens.

Role of microbiological tests and biomarkers in antibiotic stewardship

Laboratory tests are critical in the detection and timely treatment of infection. Two categories of tests are commonly used in neonatal sepsis management: those that identify the pathogen and those that detect host response to a potential pathogen. Decision-making around antibiotic choice is related to the performance of tests that directly identify pathogens. Advances in these tests hold the key to progress in antibiotic stewardship. Tests measuring host response, on the other hand, are an indirect marker of potential infection. While an important measure of the patient's clinical state, in the absence of pathogen detection these tests cannot confirm the appropriateness of antibiotic selection. The overall impact these tests then have on antibiotic utilization depends the test's specificity for bacterial infection, clinical scenario where it is being used and the decision-rule it is being integrated into for use. In this review we discuss common and emerging laboratory tests available for assisting management of neonatal infection and specifically focus on the role they play in optimizing antibiotic utilization.

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.

Derivation of a metabolic signature associated with bacterial meningitis in infants

BACKGROUND

Diagnosis of bacterial meningitis (BM) is challenging in newborn infants. Presently, biomarkers of BM have limited diagnostic accuracy. Analysis of cerebrospinal fluid (CSF) metabolites may be a useful diagnostic tool in BM.

METHODS

In a nested case-control study, we examined >400 metabolites in CSF of uninfected infants and infants with culture-confirmed BM using gas and liquid chromatography mass spectrometry. Preterm and full-term infants in a Level III or IV Neonatal Intensive Care Unit were prospectively enrolled when evaluated for serious bacterial infection.

RESULTS

Over 200 CSF metabolites significantly differed in uninfected infants and infants with BM. Using machine learning, we found that as few as 6 metabolites distinguished infants with BM from uninfected infants in this pilot cohort. Further analysis demonstrated three metabolites associated with Group B Streptococcal meningitis.

CONCLUSIONS

We report the first comprehensive metabolic analysis of CSF in infants with BM. In our pilot cohort, we derived a metabolic signature that predicted the presence or absence of BM, irrespective of gestational age, postnatal age, sex, race and ethnicity, presence of neurosurgical hardware, white blood cell count in CSF, and red blood cell contamination in CSF. Metabolic analysis may aid diagnosis of BM and facilitate clinical decision-making in infants.

IMPACT

In a pilot cohort, metabolites in cerebrospinal fluid distinguished infants with bacterial meningitis from uninfected infants.We report the first comprehensive metabolic analysis of cerebrospinal fluid in infants with bacterial meningitis.Our findings may be used to improve diagnosis of bacterial meningitis and to offer mechanistic insights into the pathophysiology of bacterial meningitis in infants.

Meningitis, urinary tract, and bloodstream infections in very low birth weight infants enrolled in a heart rate characteristics monitoring trial

BACKGROUND

Displaying heart rate characteristic (HRC) scores was associated with lower sepsis-associated mortality in very low birth weight (VLBW) infants in a multicenter randomized controlled trial (HeRO trial). The aim of this study was to test whether HRC indices rise before diagnosis of urinary tract infection (UTI) or meningitis, with and without concomitant BSI.

METHODS

Blood, urine, and cerebrospinal fluid (CSF) culture data after 3 days of age and within 120 days of study enrollment were analyzed from 2989 VLBW infants. The HRC index was analyzed 12 h prior to positive cultures compared to 36 h prior, using paired signed-rank tests.

RESULTS

UTI, meningitis, and BSI were diagnosed in 10%, 2%, and 24% of infants, respectively. The mean hourly HRC index was significantly higher 12 h prior to diagnosis of UTI and BSI compared to 36 h prior (UTI 2.07 versus 1.81; BSI 2.62 versus 2.25, both p < 0.0001). The baseline HRC index was higher for meningitis, compared to UTI or BSI, but without a statistically significant rise in the day prior to meningitis diagnosis.

CONCLUSIONS

In a large cohort of VLBW infants enrolled in the HeRO trial, the HRC index increased in the 24-h period prior to diagnosis of UTI and BSI but not meningitis.

Fecal Volatile Organic Compound Profiles are Not Influenced by Gestational Age and Mode of Delivery: A Longitudinal Multicenter Cohort Study

Fecal volatile organic compounds (VOC) reflect human and gut microbiota metabolic pathways and their interaction. VOC behold potential as non-invasive preclinical diagnostic biomarkers in various diseases, e.g., necrotizing enterocolitis and late onset sepsis. There is a need for standardization and assessment of the influence of clinical and environmental factors on the VOC outcome before this technique can be applied in clinical practice. The aim of this study was to investigate the influence of gestational age (GA) and mode of delivery on the fecal VOC pattern in preterm infants born below 30 weeks of gestation. Longitudinal fecal samples, collected on days 7, 14, and 21 postnatally, were analyzed by an electronic nose device (Cyranose 320^®). In total, 58 preterm infants were included (29 infants born at GA 24–26 weeks vs. 29 at 27–29 completed weeks, 24 vaginally born vs. 34 via C-section). No differences were identified at any predefined time point in terms of GA and delivery mode (p > 0.05). We, therefore, concluded that correction for these factors in this population is not warranted when performing fecal VOC analysis in the first three weeks of life.

Neonatal sepsis in low-income countries: epidemiology, diagnosis and prevention

Introduction: Sepsis accounts for up to one-third of neonatal deaths in the world each year. The World Health Organization acknowledges neonatal sepsis as a major global health concern, and that the highest burden occurs in low- and middle-income countries (LMICs). Despite major research and clinical progress in this area, we still lack accurate diagnostic tools for neonatal sepsis, complicating the management of this condition.Areas covered: The purpose here is to review the latest data on the incidence, diagnosis, prevention, and management of neonatal sepsis in LMIC. We discuss the limitations of current diagnostic tests - including their lack of availability - and how this may influence global estimates of cases. We review the benefits of antenatal, intrapartum, and post-natal preventive measures. We briefly discuss the management, highlighting the emergence of antimicrobial resistance. Finally, we expose some high priority areas.Expert opinion: Neonatal sepsis is a challenging condition requiring a multifaceted approach to address the major diagnostic issues, but also the underlying socio-economic causes that nourish epidemic cases in LMIC. Focusing on antibiotics as a main pillar of intervention is likely to engender antimicrobial resistance, eventually hindering the appreciable gains LMICs have achieved in neonatal health outcomes.

Neonatal bacterial meningitis versus ventriculitis: a cohort-based overview of clinical characteristics, microbiology and imaging

Central nervous system (CNS) infections are potentially life threatening in neonates and can lead to the ill-defined diagnosis of ventriculitis. With this study we aimed to explore and describe ventriculitis regarding clinical, microbiological and ultrasonographic characteristics. We performed a retrospective cohort study including all neonates with a culture-proven CNS infection admitted to our tertiary NICU over a 12-year period (2004-2016). For each case clinical data was gathered, and three timed cranial ultrasounds were anonymized and retrospectively reviewed and assessed for signs of ventriculitis. Forty-five patients were included with 9 (20%) diagnosed with ventriculitis. Mortality in both ventriculitis and non-ventriculitis cases was one-third. Patients with pre-existing conditions as post-haemorrhagic hydrocephalus are at risk of developing ventriculitis. Most common pathogens were gram negative bacteria (68.9%). Ultrasonographic signs of ventriculitis developed over time, and interrater agreement was substantial.Conclusion: Neonatal ventriculitis is a serious entity in the continuum of meningitis. Early and correct diagnoses of ventriculitis are both important because of possible persisting or newly developing hydrocephalus or seizures. Sequential imaging should be performed. What is Known: • CNS infections in neonates lead to high mortality and morbidity. • Ventriculitis is a severe complication of meningitis. What is New: • High morbidity; the majority of ventriculitis patients have pre-existing PHVD and develop seizures and hydrocephalus. • Interrater agreement is good; bedside CUS is a useful tool for reaching a sustainable diagnosis of ventriculitis.

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.

Accuracy of Using a Point-of-Care Glucometer for Cerebrospinal Fluid Glucose Screening in Resource-Limited Countries

OBJECTIVES

To explore the accuracy of using a point-of-care (POC) glucometer for cerebrospinal fluid (CSF) glucose screening.

METHODS

A cross-sectional study was conducted. A glucose analysis of CSF samples collected from infants <90 days with suspected meningitis was paired between tests by using a POC glucometer (POC-CSF glucose) and a laboratory glucose analysis (laboratory-CSF glucose). Accuracy and limits of agreement were compared, as well as the glucometer performance to detect a laboratory-CSF glucose level <45 and 60 mg/dL.

RESULTS

Seventy-three CSF samples were analyzed. Subjects' mean gestational age was 32.2 (SD 4.0) weeks, the mean weight was 1947.7 (SD 814.5) g, and the median age was 8 (interquartile range: 2 to 19.5) days. POC-CSF glucose levels ranged from 26 to 126 mg/dL. The mean (±1.96 SD) difference between POC-CSF and laboratory-CSF glucose levels was -1.6 (interquartile range: -12.6 to 9.4) mg/dL. A POC-CSF glucose level <45 mg/dL has a sensitivity and negative predictive value (NPV) to detect a laboratory-CSF glucose level <45 mg/dL of 82% and 94%, respectively. For a laboratory-CSF glucose level <60 mg/dL, a POC glucose level <60 mg/dL provides a sensitivity and NPV of 96% and 90%, respectively, whereas sensitivity and NPV reach 100% at a POC glucose level <70 mg/dL.

CONCLUSIONS

A POC glucometer for CSF glucose can detect a potential abnormal glucose level with an appropriate cutoff level. This may facilitate rapid decisions for empirical antibiotics in suspected meningitis, pending laboratory results in limited-resource settings, but requires robust validation in future studies before implementation.

Role of beta-2-microglobulin as a biomarker in very preterm and extremely preterm infants with CNS inflammation

Background

Premature infants are at risk for severe sepsis and meningitis, both infections associated with high mortality and morbidity. Cerebro-spinal fluid (CSF) culture is the gold standard method for meningitis diagnosis, but interpretation of biochemical parameters of CSF is essential at the moment of the analysis in order to start the appropriate treatment. The main objective of this study was to determine whether levels of CSF beta-2-microglobulin (B2M) were elevated in preterm infants with CNS infections or other inflammatory processes, and to establish if there were differences in B2M concentrations amongst various inflammatory settings (sepsis, meningitis, and progressive post-hemorrhagic ventricular dilatation (PHVD)).

Methods

This is a retrospective study of all very preterm and extremely preterm infants (< 32 weeks of gestation) admitted to our NICU between 2012 and 2017. All those who underwent a lumbar puncture during their stay as part of a sepsis work-up or PHVD were considered for inclusion. CSF biochemical parameters and B2M were tested in all of the patients.

Results

Fifty-nine patients were included in the study. In patients with CNS infections, the median value of B2M was 8.69 mg/L (3.92–18.5). B2M levels above 3.92 mg/L showed greater sensitivity and specificity than leukocyte levels in discriminating between patients with CNS infections or other inflammatory processes and those without CNS inflammation.

Conclusions

In this population, CSF B2M proved to be an effective biomarker to discriminate between patients with CNS infections and other inflammatory processes and those without CNS inflammation.

Epidemiology of Meningitis in Canadian Neonatal Intensive Care Units

BACKGROUND

Meningitis is a serious disease that occurs more commonly in the neonatal period than in any other age group. Recent data from large national cohorts are needed to determine if the epidemiology of neonatal meningitis (NM) has changed.

AIM

To assess the rates, causative organisms, risk factors, temporal trends and short-term outcomes of NM in Canadian Neonatal Intensive Care Units (NICUs).

METHODS

A retrospective review of newborn infants admitted to NICUs participating in the Canadian Neonatal Network between January 2010 and December 2016. Patients with meningitis were reviewed. Outcomes of patients with meningitis were compared with 1:2 matched (for gestation, sex and birth weight) neonates without meningitis.

RESULTS

Rates of NM ranged between 2.2 and 3.5/1000 NICU admissions during the 7-year study period with the majority of patients (87%) having late-onset meningitis (at >3 days after birth). The most common bacterial organism for both early- and late-onset meningitis was Escherichia coli followed by group B streptococci. Only 31% [95% confidence interval (CI): 24.06-38.63) of neonates with meningitis had simultaneous bacteremia. NM was associated with increased seizures [odds ratio (OR): 8.63; 95% CI: 4.73-15.7], retinopathy of prematurity (OR: 3.23; 95% CI: 1.30-8.02), bronchopulmonary dysplasia (OR: 1.93; 95% CI: 1.11-3.35), days of mechanical ventilation (OR: 1.03; 95% CI: 1.02-1.04) and length of hospital stay (OR: 1.02; 95% CI: 1.01-1.02), but not with mortality before discharge (OR: 1.29; 95% CI: 0.74-2.23).

CONCLUSIONS

The rate of NM remains largely unchanged in Canadian NICUs. NM was associated with increased major morbidities and longer hospital stay but not with mortality before discharge.

Development of a TaqMan Array card to target 21 purulent meningitis-related pathogens

Background

Purulent meningitis (PM) is a serious life-threatening infection of the central nervous system (CNS) by bacteria or fungi and associated with high mortality and high incidence of CNS sequelae in children. However, the conventional cerebrospinal fluid (CSF) culture method is time-consuming and has a low sensitivity.

Methods

Our study developed a real-time PCR-based purulent meningitis-TaqMan array card (PM-TAC) that targeted 21 PM-related pathogens and could produce results within 3 h. Primers and probes were adapted from published sources possibly. The performance of them were evaluated and optimized and then they were spotted on TAC.

Results

The PM-TAC showed a sensitivity and specificity of 95 and 96%, respectively. For all of the 21 targeted pathogens, the PM-TAC assay had a LOD ranging from 5 copies/reaction to 100 copies/reaction, an intra-assay variation of 0.07–4.45%, and an inter-assay variation of 0.11–6.81%. Of the 15 CSF samples collected from patients with PM after empiric antibiotic therapies, the positive rate was 53.3% (8/15) for our PM-TAC assay but was only 13.3% (2/15) for the CSF culture method. Of the 17 CSF samples showing negative CSF culture, the PM-TAC assay identified a case of Neisseria meningitidis infection. Furthermore, all of the 10 CSF samples from patients without CNS infection showed negative for the PM-TAC assay.

Conclusions

Our PM-TAC assay also demonstrated that the pathogen loads in the CSF samples correlated with the severity of PM. Thus, the PM-TAC may be helpful to improve the prognosis of PM and clinical outcomes from antibiotic therapies.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3856-z) contains supplementary material, which is available to authorized users.

When to Include a Lumbar Puncture in the Evaluation for Neonatal Sepsis

Meningitis is a devastating infection in infants and is linked to adverse long-term outcomes. The prevalence of meningitis is variable and depends on gestational age, postnatal age, and clinical setting. Early diagnosis and treatment with appropriate antibiotics are crucial to decrease the risk of morbidity and mortality. Lumbar punctures are essential for the diagnosis of meningitis, but clinicians may defer lumbar puncture if the risk for meningitis is low or if there are substantial concerns regarding the risk associated with the procedure. Awareness of the epidemiology and microbiology of meningitis in infants, as well as valid contraindications to performing a lumbar puncture, is necessary to avoid missed diagnoses and procedure-related adverse effects.

C-reactive protein and immature-to-total neutrophil ratio have no utility in guiding lumbar puncture in suspected neonatal sepsis

AIM

Meningitis may complicate neonatal sepsis, but there is scant evidence to inform the decision to perform a lumbar puncture (LP) and considerable variation in practice. We investigated whether inflammatory markers - C-reactive protein (CRP) and immature-to-total neutrophil ratio (ITR) - were predictive of meningitis or significant cerebrospinal fluid (CSF) pleocytosis and useful in guiding the decision to perform a LP.

METHODS

We studied all inpatients in a single tertiary neonatal unit who were <6 months of age who had a LP performed between March 2011 and October 2014. We categorised CSF results as follows: (i) culture-positive meningitis; (ii) probable culture-negative meningitis but meeting a priori criteria for significant CSF leucocytosis; or (iii) no evidence of meningitis. CRP and ITR obtained within 48 h of LP were analysed. We assessed the test performance of CRP and ITR by area under receiver operating characteristic curves.

RESULTS

A total of 757 (male 471, 62.2%) infants were included. The median (interquartile range) gestational age was 38.4 weeks (30-40.3), and birthweight was 2940 g (1330-3560). Ten (1.3%) infants had culture-positive meningitis; 71 (9.4%) were classified as probable culture-negative meningitis and 676 (89.3%) as non-meningitis. The area under receiver operating characteristic curve for culture-positive and probable culture-negative meningitis was 0.43 for CRP (95% confidence interval 0.36-0.51) and 0.58 for ITR (0.51-0.65). At a CRP threshold of 30 mg/L, there was a positive likelihood ratio (LR) of 0.77 and a negative LR of 1.44.

CONCLUSIONS

CRP and ITR perform poorly in identifying infants with confirmed or probable meningitis. The decision to perform an LP should be more focused on clinical grounds and/or a positive blood culture and less on inflammatory or haematological markers in isolation.

Late onset sepsis: comparison between coagulase-negative staphylococci and other bacteria in the neonatal intensive care unit

OBJECTIVE

To compare demographic and clinical features of neonates with late-onset sepsis due to coagulase-negative-staphylococcus with those due to other bacterial pathogens.

STUDY DESIGN

Retrospective, population-based cohort study. Data on infants less than 90 days old diagnosed with late-onset bacterial sepsis in the neonatal intensive care unit were reviewed. Univariable and multivariable analysis were performed.

RESULTS

Two hundred and sixteen sepsis episodes were identified: coagulase-negative-staphylococcus caused 113 (52.3%) and other pathogen 103 (47.7%). Patients with coagulase-negative-staphylococcus sepsis had lower gestational age and younger age at onset, higher rates of parenteral nutrition exposure and normal temperature, lower rates of necrotizing enterocolitis, meningitis and neutropenia than patients with sepsis caused by other pathogens. In multivariable analysis, parenteral nutrition was the only independent risk factor for coagulase-negative-staphylococcus sepsis (odds ratio: 3.5, 95% confidence interval: 1.4-8.6).

CONCLUSIONS

Initial empiric treatment for suspected sepsis should be targeted for other pathogens than coagulase-negative-staphylococci and vancomycin treatment should be reserved for infants with specific risk factors and according to local antimicrobial susceptibility.

Pitfalls in the diagnosis of meningitis in neonates and young infants: the role of lumbar puncture

Meningitis occurs frequently in neonates and can lead to a number of acute, severe complications and long-term disabilities. An early diagnosis of neonatal meningitis is essential to reduce mortality and to improve outcomes. Initial clinical signs of meningitis are often subtle and frequently overlap with those of sepsis, and current haematologic tests do not distinguish sepsis from meningitis. Thus, lumbar puncture (LP) remains the gold standard for the diagnosis of meningitis in infants, and this procedure is recommended in clinical guidelines. Nevertheless, in clinical practice, LP is frequently deferred or omitted due to concerns regarding hypothetical adverse events or limited experience of the performer. Future studies should assess whether a combination of clinical findings and select haematologic tests at disease onset can identify those neonates with the highest risk of meningitis who should undergo LP. Furthermore, clinicians should be convinced that the actual benefits of an early diagnosis of meningitis far outweigh the hypothetical risks associated with LP.

Elevations of novel cytokines in bacterial meningitis in infants

Background

Bacterial meningitis is challenging to diagnose in infants, especially in the common setting of antibiotic pre-treatment, which diminishes yield of cerebrospinal fluid (CSF) cultures. Prior studies of diagnostic markers have not demonstrated sufficient accuracy. Interleukin-23 (IL-23), interleukin-18 (IL-18) and soluble receptor for advanced glycation end products (sRAGE) possess biologic plausibility, and may be useful as diagnostic markers in bacterial meningitis.

Methods

In a prospective cohort study, we measured IL-23, IL-18 and sRAGE levels in CSF. We compared differences between infected and non-infected infants, and conducted receiver operating characteristic (ROC) analyses to identify individual markers and combinations of markers with the best diagnostic accuracy.

Results

189 infants <6 months, including 8 with bacterial meningitis, 30 without meningitis, and 151 with indeterminate diagnosis (due to antibiotic pretreatment) were included. CSF IL-23, IL-18 and sRAGE levels were significantly elevated in infants with culture proven meningitis. Among individual markers, IL-23 possessed the greatest accuracy for diagnosis of bacterial meningitis (area under the curve (AUC) 0.9698). The combination of all three markers had an AUC of 1.

Conclusions

IL-23, alone and in combination with IL-18 and sRAGE, identified bacterial meningitis with excellent accuracy. Following validation, these markers could aid clinicians in diagnosis of bacterial meningitis and decision-making regarding prolongation of antibiotic therapy.

Early lumbar puncture and risk of intraventricular hemorrhage in very low birth weight infants

BACKGROUND

Lumbar puncture (LP) is the gold standard for diagnosing meningitis; however it is unknown whether early LP (≤3days of life) is associated with increased risk of intraventricular hemorrhage (IVH) in very low birth weight (VLBW) infants.

OBJECTIVE

To determine whether early LP in VLBW infants is associated with severe IVH.

METHODS

VLBW infants from a cohort of 1,158,789 infants discharged from 382 neonatal intensive care units (1997-2015) were enrolled.

EXCLUSION CRITERIA

infants with major congenital anomalies, outborns, died/transferred prior to day of life 3, and those who had an LP performed only after day of life 3. Logistic regression was used to determine the association between early LP and the incidence of severe IVH (IVH grades 3/4) by 28days of life for each day of life from day 0 (birth) to day 3, adjusting for clinical covariates.

RESULTS

106,461 infants were included: 754 received an LP on Day-0, 640 on Day-1, 559 on Day-2 and 483 on Day-3. Severe IVH occurred in 4% (4130/104,025) of the infants in the no LP group and 9% (217/2436) of the LP group. Severe IVH was higher for infants with early LP: adjusted OR (95% confidence interval)=2.64 (1.96-3.54) on Day-0; 2.21 (1.61-3.04) on Day-1; 1.55 (1.03-2.34) on Day-2; and 2.25 (1.50-3.38) on Day-3.

CONCLUSIONS

Early LP was associated with severe IVH in VLBW infants by 28days of life. LP is either a surrogate for an unrecognized factor or is itself associated with an increased risk of IVH.

Neonatal sepsis

Neonatal sepsis is the cause of substantial morbidity and mortality. Precise estimates of neonatal sepsis burden vary by setting. Differing estimates of disease burden have been reported from high-income countries compared with reports from low-income and middle-income countries. The clinical manifestations range from subclinical infection to severe manifestations of focal or systemic disease. The source of the pathogen might be attributed to an in-utero infection, acquisition from maternal flora, or postnatal acquisition from the hospital or community. The timing of exposure, inoculum size, immune status of the infant, and virulence of the causative agent influence the clinical expression of neonatal sepsis. Immunological immaturity of the neonate might result in an impaired response to infectious agents. This is especially evident in premature infants whose prolonged stays in hospital and need for invasive procedures place them at increased risk for hospital-acquired infections. Clinically, there is often little difference between sepsis that is caused by an identified pathogen and sepsis that is caused by an unknown pathogen. Culture-independent diagnostics, the use of sepsis prediction scores, judicious antimicrobial use, and the development of preventive measures including maternal vaccines are ongoing efforts designed to reduce the burden of neonatal sepsis.

Granulocytic myeloid-derived suppressor cells from human cord blood modulate T-helper cell response towards an anti-inflammatory phenotype

Infections are a leading cause of perinatal morbidity and mortality. The outstandingly high susceptibility to infections early in life is mainly attributable to the compromised state of the neonatal immune system. One important difference to the adult immune system is a bias towards T helper type 2 (Th2) responses in newborns. However, mechanisms regulating neonatal T-cell responses are incompletely understood. Granulocytic myeloid-derived suppressor cells (GR-MDSC) are myeloid cells with a granulocytic phenotype that suppress various functions of other immune cells and accumulate under physiological conditions during pregnancy in maternal and fetal blood. Although it has been hypothesized that GR-MDSC accumulation during fetal life could be important for the maintenance of maternal-fetal tolerance, the influence of GR-MDSC on the immunological phenotype of neonates is still unclear. Here, we investigated the impact of GR-MDSC isolated from cord blood (CB-MDSC) on the polarization of Th cells. We demonstrate that CB-MDSC inhibit Th1 responses and induced Th2 responses and regulatory T (Treg) cells. Th1 inhibition was cell-contact dependent and occurred independent of other cell types, while Th2 induction was mediated independently of cell contact through expression of ArgI and reactive oxygen species by CB-MDSC and partially needed the presence of monocytes. Treg cell induction by CB-MDSC also occurred cell-contact independently but was partially mediated through inducible nitric oxide synthase. These results point towards a role of MDSC in regulating neonatal immune responses. Targeting MDSC function in neonates could be a therapeutic opportunity to improve neonatal host defence.

Maternal human immunodeficiency virus status and morbidity and mortality in very low birthweight infants

BACKGROUND

Human immunodeficiency virus (HIV) remains a common cause of infection in pregnant women. The effect of HIV exposure on growth, morbidity and mortality in very low-birthweight infants (VLBWI) is under-reported.

AIM

To determine anthropometry at birth, morbidity during hospital stay and mortality at hospital discharge of VLBWI stratified according to HIV-exposure in a tertiary public government hospital in Johannesburg, South Africa.

METHODS

Retrospective descriptive study. Records of VLBWI were reviewed for maternal HIV status, infant characteristics, diagnosis and outcome to hospital discharge. Anthropometry, morbidity and mortality were compared according to HIV-exposure.

RESULTS

Of 302 VLBWI,103 (34.1%)were HIV-exposed. Among the 103mothers, 38 (36.9%)were on combined anti-retroviral therapy (cART), 41 (39.8%) were on zidovudine (AZT) and 24 (23%) were not on either. More HIV-exposed VLBWI weighed v1000 g (41.2 vs 23.1%, Pv0.01). There were no differences in incidence or number of episodes of sepsis between HIV-exposed and -unexposed. More HIV-exposed VLBWI had severe intraventricular haemorrhage (IVH) (57.1 vs 11.4%, Pv0.01). The overall mortality rate was 27%, with HIV-exposed VLBWI having a mortality rate of 38.6% compared with 21% of the HIV-unexposed (Pv0.01). On multivariate analysis, the predictor of mortality was birthweight (Pv0.01).

CONCLUSION

HIV-exposed VLBWI are more likely to have extremely low birthweights. Morbidity in VLBWI is not affected by HIV-exposure, except for severe IVH. Birthweight is a predictor of mortality in VLBWI, irrespective of maternal HIV status.

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.

Neonatal Meningitis: Overcoming Challenges in Diagnosis, Prognosis, and Treatment with Omics

Neonatal meningitis is a devastating condition. Prognosis has not improved in decades, despite the advent of improved antimicrobial therapy and heightened index of suspicion among clinicians caring for affected infants. One in ten infants die from meningitis, and up to half of survivors develop significant lifelong complications, including seizures, impaired hearing and vision, and delayed or arrested development of such basic skills as talking and walking. At present, it is not possible to predict which infants will suffer poor outcomes. Early treatment is critical to promote more favorable outcomes, though diagnosis of meningitis in infants is technically challenging, time-intensive, and invasive. Profound neuronal injury has long been described in the setting of neonatal meningitis, as has elevated levels of many pro- and anti-inflammatory cytokines. Mechanisms of the host immune response that drive clearance of the offending organism and underlie brain injury due to meningitis are not well understood, however. In this review, we will discuss challenges in diagnosis, prognosis, and treatment of neonatal meningitis. We will highlight transcriptomic, proteomic, and metabolomic data that contribute to suggested mechanisms of inflammation and brain injury in this setting with a view toward fruitful areas for future investigation.

Preventing group B streptococcal infections in newborns

Despite advances in intrapartum antibiotic prophylaxis (IAP), group B streptococcal infection continues to be a predominant cause of early-onset disease in neonates. About 2% of neonates exposed to group B Streptococcus develop clinical manifestations including sepsis, pneumonia, and meningitis. Screening in late pregnancy reduces the incidence of early-onset sepsis by more than 80%. Clinicians must be able to identify the risk factors and clinical manifestations of group B streptococcal infection and to understand management and prevention guidelines.