Late-onset sepsis caused by Gram-negative bacteria in very low birth weight infants: a systematic review

Late-Onset Sepsis among Extremely Preterm Infants of 24-28 Weeks Gestation: An International Comparison in 10 High-Income Countries

INTRODUCTION

Despite advances in neonatal care, late-onset sepsis remains an important cause of preventable morbidity and mortality. Neonatal late-onset sepsis rates have decreased in some countries, while in others they have not. Our objective was to compare trends in late-onset sepsis rates in 9 population-based networks from 10 countries and to assess the associated mortality within 7 days of late-onset sepsis.

METHODS

We performed a retrospective population-based cohort study. Infants born at 24-28 weeks' gestation between 2007 and 2019 were eligible for inclusion. Late-onset sepsis was defined as a positive blood or cerebrospinal fluid culture. Late-onset sepsis rates were calculated for 3 epochs (2007-11, 2012-15, and 2016-19). Adjusted risk ratios (aRRs) for late-onset sepsis were calculated for each network.

RESULTS

Of a total of 82,850 infants, 16,914 (20.4%) had late-onset sepsis, with Japan having the lowest rate (7.1%) and Spain the highest (44.6%). Late-onset sepsis rates decreased in most networks and remained unchanged in a few. Israel, Sweden, and Finland showed the largest decrease in late-onset sepsis rates. The aRRs for late-onset sepsis showed wide variations between networks. The rate of mortality temporally related to late-onset sepsis was 10.9%. The adjusted mean length of stay for infants with late-onset sepsis was increased by 5-18 days compared to infants with no late-onset sepsis.

CONCLUSIONS

One in 5 neonates of 24-28 weeks' gestation develops late-onset sepsis. Wide variability in late-onset sepsis rates exists between networks with most networks exhibiting improvement. Late-onset sepsis was associated with increased mortality and length of stay.

Impact of Physician Characteristics on Late-Onset Sepsis (LOS) Evaluation in the NICU

The threshold for a late-onset sepsis (LOS) evaluation varies considerably across NICUs. This unexplained variability is probably related in part to physician bias regarding when sepsis should be "ruled out". The aim of this study is to determine if physician characteristics (race, gender, immigration status, years of experience and academic rank) effect LOS evaluation in the NICU. This study includes a retrospective chart review of all Level III NICU infants who had a LOS evaluation over 54 months. Physician characteristics were compared between positive and negative blood culture groups and whether CBC and CRP were obtained at LOS evaluations. There were 341 LOS evaluations performed during the study period. Two patients were excluded due to a contaminant. Patients in this study had a birth weight of [median (Q1, Q3)]+ 992 (720, 1820) grams and birth gestation of [median (Q1, Q3)] 276/7 (252/7, 330/7) weeks. There are 10 neonatologists in the group, 5/10 being female and 6/10 being immigrant physicians. Experienced physicians were more likely to obtain a CBC at the time of LOS evaluation. Physician characteristics of race, gender and immigration status impacted whether to include a CRP as part of a LOS evaluation but otherwise did not influence LOS evaluation, including the likelihood of bacteremia.

Burden of antibiotic resistance in infections among very-low-birthweight infants in Singapore

Introduction

Recent reports have described the increasing predominance of Gram-negative organisms among invasive bacterial infections affecting preterm infants. This changing pattern of infections is concerning due to the spread of antibiotic resistance among Gram-negatives.

Method

We conducted a single-centre, retrospective cohort study involving very-low-birthweight (VLBW) (<1500 grams) infants born <32 weeks gestation, with culture-proven infections (blood, urine, cerebrospinal fluid [CSF]) in the neonatal intensive care unit from 1 January 2005 to 31 October 2017.

Results

A total of 278 out of 2431 (11.4%) VLBW infants born <32 weeks gestation developed 334 infections, i.e. 52 (15.6%) early-onset infections (EOIs) and 282 (84.4%) late-onset infections (LOIs). The overall incidence decreased from 247 to 68 infections per 1000 infants over the study period, corresponding to reductions in LOI (211 to 62 infections per 1000 infants). A total of 378 bacteria were isolated, i.e. Gram-negatives accounted for 70.9% (45 of 59 [76.3%] EOI; 223 of 319 [69.9%] LOI). Specific resistant organisms were noted, i.e. Methicillin-resistant Staphylococcus aureus (8 of 21 S. aureus infections [38.1%]); Cephalosporin-resistant Klebsiella (18 of 62 isolates [29.0%]) and multidrug-resistant [MDR] Acinetobacter (10 of 27 isolates [37.0%]). MDR organisms accounted for 85 of 195 (43.6%) Gram-negative infections from the bloodstream and CSF. Based on laboratory susceptibility testing, only 63.5% and 49.3% of infecting bacteria isolated in blood were susceptible to empiric antibiotic regimens used for suspected EOI and LOI, respectively.

Conclusion

Gram-negative bacteria are the predominant causative organisms for EOI and LOI and are frequently MDR. Understanding the pattern of antimicrobial resistance is important in providing appropriate empiric coverage for neonatal infections.

Late-Onset Sepsis in Very Low Birth Weight Infants

BACKGROUND AND OBJECTIVES

Late-onset sepsis is associated with significant morbidity and mortality among very low birth weight (VLBW) infants. Our objective was to determine risk factors associated with late-onset sepsis and to present temporal trends in overall and pathogen-specific rates.

METHODS

Population-based study by the Israel Neonatal Network on VLBW infants (≤1500 g) born between 1995 and 2019. Late-onset sepsis required clinical symptoms and microbiologic confirmation. Bivariate and multivariable analyses were performed to identify risk factors. The study period was divided into 4 epochs. Overall and pathogen-specific late-onset sepsis rates for each epoch were compared.

RESULTS

The study population comprised 31 612 VLBW infants, of whom 7423 (23.5%) had late-onset sepsis. An increased adjusted risk of late-onset sepsis was associated with gestational age <27 w (odds ratio [OR] 8.90, 95% confidence interval [CI] 7.85-10.09) and delivery room resuscitation (OR 1.43, 95% CI 1.34-1.52) and a decreased adjusted risk among infants born between 2013 and 2019 (OR 0.32, 95% CI 0.29-0.35). Late-onset sepsis rates declined from 29.5% in 1995 to 2000 to 13.0% in 2013 to 2019. Gram-negative and fungal rates decreased in all epochs, whereas gram-positive rates decreased only in the last epoch. The adjusted hazard ratios (95% CI) decreased in the 2013 to 2019 versus 1995 to 2000 epochs and were: all late-onset sepsis, 0.40 (0.37-0.43); gram-positive, 0.47 (0.37-0.59); gram- negative, 0.54 (0.48-0.61); fungal, 0.17 (0.12-0.22).

CONCLUSIONS

The strongest risk factor for late-onset sepsis was gestational age <27 w. Over a 25-year period, the pathogen-specific rates of late-onset sepsis among VLBW infants decreased approximately twofold for gram-positive and gram-negative bacterial infections and sixfold for fungal infections.

Commensal Bacteria Impact on Intestinal Toll-like Receptor Signaling in Salmonella-Challenged Gnotobiotic Piglets

Gnotobiotic (GN) animals with simple and defined microbiota can help to elucidate host-pathogen interferences. Hysterectomy-derived germ-free (GF) minipigs were associated at 4 and 24 h post-hysterectomy with porcine commensal mucinolytic Bifidobacterium boum RP36 (RP36) strain or non-mucinolytic strain RP37 (RP37) or at 4 h post-hysterectomy with Lactobacillus amylovorus (LA). One-week-old GN minipigs were infected with Salmonella Typhimurium LT2 strain (LT2). We monitored histological changes in the ileum, mRNA expression of Toll-like receptors (TLRs) 2, 4, and 9 and their related molecules lipopolysaccharide-binding protein (LBP), coreceptors MD-2 and CD14, adaptor proteins MyD88 and TRIF, and receptor for advanced glycation end products (RAGE) in the ileum and colon. LT2 significantly induced expression of TLR2, TLR4, MyD88, LBP, MD-2, and CD14 in the ileum and TLR4, MyD88, TRIF, LBP, and CD14 in the colon. The LT2 infection also significantly increased plasmatic levels of inflammatory markers interleukin (IL)-6 and IL-12/23p40. The previous colonization with RP37 alleviated damage of the ileum caused by the Salmonella infection, and RP37 and LA downregulated plasmatic levels of IL-6. A defined oligo-microbiota composed of bacterial species with selected properties should probably be more effective in downregulating inflammatory response than single bacteria.

Device-associated infections in neonatal care units in a middle-income country, 2016-2018

OBJECTIVE

Describe the device-associated infections in the NICUs in Cali - Colombia, a middle-income country, between August 2016 to December 2018.

METHODS

Observational cross-sectional study evaluating reports of device-associated infections in 10 NICUs in Cali, Colombia, between August 2016 and December 2018. Socio-demographic and microbiological data were obtained from the National Public Health surveillance system, through a specialized notification sheet. The relationship of device-associated infections with several outcomes including birth weight, microorganisms, and mortality was evaluated using OR CI95%, using the logistic regression model. Data processing was performed using the statistical program STATA 16.

RESULTS

226 device-associated infections were reported. The rate of infection with central line-associated bloodstream infections was 2.62 per 1000 days of device use and 2.32 per 1000 days for ventilator-associated pneumonia. This was higher in neonates under 1000 g; 4.59 and 4.10, respectively. 43.4% of the infections were due to gram-negative bacteria and 42.3% were due to gram-positive bacteria. Time from hospitalization to diagnosis of all device-associated infections had a median of 14 days. When compared by weight, infants with a weight lower than 1000 g had a greater chance of death (OR 3.61; 95% CI 1.53-8.49, p = 0.03). Infection by gram-negative bacteria was associated with a greater chance of dying (OR 3.06 CI 95 1.33-7.06, p = 0.008).

CONCLUSIONS

These results highlight the need to maintain epidemiological surveillance processes in neonatal intensive care units, especially when medical devices are used.

Clinical and laboratory findings to differentiate late-onset sepsis caused by Gram-negative vs Gram-positive bacteria among perterm neonates: A retrospective cohort study

PURPOSE

Late-onset sepsis (LOS) is a clinical condition that results in serious morbidity and mortality in preterm neonates. The aim of this study was to identify differences in clinical and laboratory findings of LOS caused by Gram-negative vs Gram-positive bacteria among perterm neonates and to evaluate the diagnostic accuracy of biomarkers.

METHODS

The retrospective cohort study included 649 preterm neonates with LOS assigned to either the Gram-positive group (n = 194, 29.89 %) or the Gram-negative group (n = 455, 70.11 %). Demographic data, serum levels of C-reactive protein (CRP), and complete blood counts at 0-24 h (T1), 24-48 h (T2), and 48-72 h (T3) were retrieved and compared.

RESULTS

At T1, T2, and T3, serum CRP levels were higher (p < 0.001), while platelet (PTL) counts were significantly lower (p < 0.001) in the Gram-negative group vs Gram-positive group. The area under the curve (AUC) of the PLT count was 0.688 (95 % confidence interval [CI] = 0.644-0.731) at T1, 0.795 (95 % CI = 0.743-0.848) at T2, and 0.785 (95 % CI = 0.739-0.831) at T3, indicating good discriminatory power, while the AUC of serum CRP was 0.654 (95 % CI = 0.61-0.697) at T1, 0.831 (95 % CI = 0.781-0.888) at T2, and 0.94 (95 % CI = 0.744-0.843) at T3.

CONCLUSIONS

Neonatal LOS caused by Gram-negative bacteria was associated with higher CRP and lower PLT levels. These results suggested that PLT and CRP values may be useful biomarkers to differentiate sepsis caused by Gram-negative vs Gram-positive bacteria among perterm neonates.

Healthcare-associated Infections in Very Low Birth-weight Infants in a South African Neonatal Unit: Disease Burden, Associated Factors and Short-term Outcomes

BACKGROUND

Infection is a leading cause of death among very low birth-weight (VLBW) infants in resource-limited settings.

METHODS

We performed a retrospective review of healthcare-associated infection (HAI) episodes among VLBW infants from January 1, 2016, to December 31, 2017. The epidemiology, causative organisms and short-term outcomes were analyzed. Logistic regression was used to investigate for factors associated with development of HAI.

RESULTS

During the study period, 715 VLBW infants with suspected HAI were investigated, including 162/715 (22.7%) proven and 158/715 (22.1%) presumed HAI. Of the proven infections, 99/162 (61.1%) contained at least one Gram-negative organism per blood culture; 84/162 (51.9%) single Gram-negative organisms and 15/162 (9.3%) polymicrobial growth. Independent factors associated with development of any HAI included low gestational age, small for gestational age, indwelling central venous catheter and invasive ventilation. Compared with infants in whom HAI had been excluded, infants with HAI were more likely to be diagnosed with necrotizing enterocolitis (5.6% vs. 23.1%; P &lt; 0.001) and bronchopulmonary dysplasia (1.0% vs. 4.4%; P = 0.007). Infants with any HAI also had a longer hospital stay [44 (25-65) vs. 38 (26-53) days; P &lt; 0.001] and increased mortality [90/320 (28.1%) vs. 21/395 (5.3%); P &lt; 0.001] compared with infants who did not develop HAI episodes.

CONCLUSIONS

Proven and presumed HAI are a major contributor to neonatal morbidity and mortality; further research is urgently needed to better understand potential targets for prevention and treatment of HAI in resource-limited neonatal units.

Neonatal sepsis and the skin microbiome

Neonatal sepsis is a major cause of morbidity and mortality in preterm infants. Preterm and very low birth weight infants are particularly susceptible to sepsis due to their immature skin barrier, naive immune system, exposure to broad-spectrum antibiotics, and insertion of medical devices. Neonatal intestinal dysbiosis has been linked to neonatal sepsis; however, the cutaneous microbiome likely plays a role as well, as common sepsis pathogens also dominate the skin flora. This review summarizes our current understanding of the infant skin microbiome and common causative pathogens in neonatal sepsis, as well as the relationship between the two. A better understanding of the role of the skin microbiome in the pathogenesis of neonatal sepsis may guide future prophylaxis and treatment.

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.

Mortality Risk Factors of Early Neonatal Sepsis During COVID-19 Pandemic

Purpose

This study aimed to determine predisposing factors for negative outcome in infants with early neonatal sepsis during COVID-19.

Patients and Methods

A prospective cohort study of 172 newborns up to 4 days diagnosed with neonatal sepsis was carried out in Karaganda (Kazakhstan). The microbiological examination was used to identify a causative agent of bloodstream infection. ELISA was performed to determine the total anti-SARS-CoV-2 antibodies. Gestational age, mode of delivery, birth weight, C-reactive protein and procalcitonin levels, comorbidities, type of pathogen, duration of hospitalization and mother’s infection diseases were used for statistical analysis.

Results

Mortality in infants with neonatal sepsis was 22% (38/172). Anti-SARS-CoV-2 antibodies were detected in 68.3% of the newborns. Culture-negative ELBW infants have a 5.3-fold higher risk of death (p<0.001). Low gestational age and a shorter period of hospitalization were statistically associated with fatality. CRP is generally higher in deceased children (p=0.002). Necrotizing enterocolitis (p<0.001), pneumonia (p=0.009) and anemia (p=0.016) were significantly associated with negative outcome. And, 31.4% of the infants with sepsis had positive blood cultures. The leading cause of sepsis in newborns was CoNS – 57%.

Conclusion

During COVID-19 pandemic neonatal sepsis mortality was associated with low birth weight, gestational age, and comorbidities as in non-pandemic time. The relationship between COVID-19 in the mother and neonatal mortality was not found. However, anti-SARS-CoV-2 antibodies were detected in more than half of newborns.

Effect of TLR-4 gene polymorphisms on sepsis susceptibility in neonates: a systematic review and meta-analysis

Aim: To clarify the role of polymorphisms rs4986790 and rs4986791 in TLR-4 with susceptibility to neonatal sepsis. Methods: To evaluate the possible correlation of polymorphisms rs4986790 and rs4986791 with sepsis risk, odds ratios (ORs) were calculated. The heterogeneity was evaluated by χ²-based Q-test. Results: For rs4986790, ORs were 1.36 (95% CI: 1.05-1.79, p = 0.017) and 1.84 (95% CI: 0.04-7.9, p = 0.410) under AG+GG versus AA and G vs. A models, respectively. For rs4986791, ORs were 2.22 (95% CI: 1.25-3.94, p = 0.006) and 2.20 (95% CI: 1.26-3.85, p = 0.005) under CT+TT versus CC and of T versus C models, respectively. Conclusion: The rs4986790 and rs4986791 polymorphisms in TLR-4 could influence the sepsis susceptibility in neonates.

Probiotics, their prophylactic and therapeutic applications in human health development: A review of the literature

Antibiotics do not differentiate between good and bad germs, disrupting normal microflora and causing vitamin deficiency in the human body. They also kill healthy bacteria in the gut and genital tract on a large scale, weakening the host's defense mechanism. Probiotics are a colony of bacteria that live in our intestines and are regarded as a metabolic 'organ' due to their beneficial effects on human health, including metabolism and immunological function. They are used in clinical settings to prevent and treat conditions such as diarrhoea, colon cancer, hypertension, diabetes, acute pancreatitis, Helicobacter pylori infection, ventilator-associated pneumonia, migraine and autism. Probiotics may modify immunological activity by increasing innate and adaptive immune responses, altering microbial habitat in the intestine, improving gut barrier function, competitive adherence to the mucosa and epithelium, and producing antimicrobial compounds. The aim of this study is to index that further in depth researches to be conducted on probiotics pivotal role in the prophylaxis and therapeutic usage for a variety of disease that may or may not have treatment alternatives. Key words such as probiotics, microbiota, prophylactics, and therapeutic applications were searched extensively in research databases such as PubMed, PubMed Central (PMC), Scopus, Web of Science, Research Gate, Google Scholar, and Cochrane Library. This concise narrative review article summarized primarily the history, selection, mechanism/mode of action, recent advances in prophylactic and therapeutic applications, and future directions in the use of probiotics for prophylactic and therapeutic applications.

Risk Factors for Mortality From Late-Onset Sepsis Among Preterm Very-Low-Birthweight Infants: A Single-Center Cohort Study From Singapore

OBJECTIVE

To determine the risk factors for mortality associated with late onset sepsis (LOS) among preterm very-low-birthweight (VLBW) infants.

STUDY DESIGN

We performed a retrospective cohort study of infants born <32 weeks gestation and <1,500 gm admitted to a Singaporean tertiary-level neonatal intensive care unit. We determined the clinical, microbial, and laboratory risk factors associated with mortality due to culture-positive LOS in this cohort.

RESULTS

A total of 1,740 infants were admitted, of which 169 (9.7%) developed LOS and 27 (16%) died. Compared to survivors, those who died had lower birth gestational age (median 24 vs. 25 weeks, p = 0.02) and earlier LOS occurrence (median 10 vs. 17 days, p = 0.007). There was no difference in the incidence of meningitis (11.1 vs. 16.9%, p = 0.3), NEC (18.5 vs. 14.8%, p = 0.6), or intestinal surgery (18.5 vs. 23.3%, p = 0.6) among infants who died compared to survivors. Gram-negative bacteria accounted for 21/27 (77.8%) LOS-associated deaths and almost all (13/14, 93%) fulminant episodes. The presence of multiorgan failure, as evidenced by the need for mechanical ventilation (100 vs. 79.0%, p = 0.008), elevated lactate (12.4 vs. 2.1 mmol/L, p < 0.001), and inotropic support (92.6 vs. 37.5%, p < 0.001), was significantly associated with mortality. Infants who died had significantly lower white blood cell (WBC) counts (median 4.2 × 109/L vs. 9.9 × 109/L, p = 0.001), lower platelet count (median 40 × 109/L vs. 62 × 109/L, p = 0.01), and higher immature to total neutrophil (I: T) ratio (0.2 vs. 0.1, p = 0.002). Inotrope requirement [AOR 22.4 (95%CI 2.9, 103.7)], WBC <4 × 109/L [AOR 4.7 (1.7, 13.2)], and I: T ratio >0.3 [AOR 3.6 (1.3, 9.7)] were independently associated with LOS mortality.

CONCLUSIONS

In a setting with predominantly Gram-negative bacterial infections, the need for inotropic support, leukopenia, and elevated I: T ratio were significantly associated with LOS mortality among preterm VLBW infants.

Look Who's Talking: Host and Pathogen Drivers of Staphylococcus epidermidis Virulence in Neonatal Sepsis

Preterm infants are at increased risk for invasive neonatal bacterial infections. S. epidermidis, a ubiquitous skin commensal, is a major cause of late-onset neonatal sepsis, particularly in high-resource settings. The vulnerability of preterm infants to serious bacterial infections is commonly attributed to their distinct and developing immune system. While developmentally immature immune defences play a large role in facilitating bacterial invasion, this fails to explain why only a subset of infants develop infections with low-virulence organisms when exposed to similar risk factors in the neonatal ICU. Experimental research has explored potential virulence mechanisms contributing to the pathogenic shift of commensal S. epidermidis strains. Furthermore, comparative genomics studies have yielded insights into the emergence and spread of nosocomial S. epidermidis strains, and their genetic and functional characteristics implicated in invasive disease in neonates. These studies have highlighted the multifactorial nature of S. epidermidis traits relating to pathogenicity and commensalism. In this review, we discuss the known host and pathogen drivers of S. epidermidis virulence in neonatal sepsis and provide future perspectives to close the gap in our understanding of S. epidermidis as a cause of neonatal morbidity and mortality.

Performance Comparison of Infection Prediction Scores in a South African Neonatal Unit: A Retrospective Case-Control Study

BACKGROUND AND OBJECTIVES

Infection prediction scores are useful ancillary tests in determining the likelihood of neonatal hospital-acquired infection (HAI), particularly in very low birth weight (VLBW; <1,500 g) infants who are most vulnerable to HAI and have high antibiotic utilization rates. None of the existing infection prediction scores were developed for or evaluated in South African VLBW neonates.

METHODS

We identified existing infection prediction scores through literature searches and assessed each score for suitability and feasibility of use in resource-limited settings. Performance of suitable scores were compared using a retrospective dataset of VLBW infants (2016-2017) from a tertiary hospital neonatal unit in Cape Town, South Africa. Sensitivity, specificity, predictive values, and likelihood ratios were calculated for each score.

RESULTS

Eleven infection prediction scores were identified, but only five were suitable for use in resource-limited settings (NOSEP1, Singh, Rosenberg, and Bekhof scores). The five selected scores were evaluated using data from 841 episodes of HAI in 659 VLBW infants. The sensitivity for the scores ranged between 3% (NOSEP1 ≥14; proven and presumed infection), to a maximum of 74% (Singh score ≥1; proven infection). The specificity of these scores ranged from 31% (Singh score ≥1; proven and presumed infection) to 100% (NOSEP1 ≥11 and ≥14, NOSEP-NEW-1 ≥11; proven and presumed infection).

CONCLUSION

Existing infection prediction scores did not achieve comparable predictive performance in South African VLBW infants and should therefore only be used as an adjunct to clinical judgment in antimicrobial decision making. Future studies should develop infection prediction scores that have high diagnostic accuracy and are feasible to implement in resource-limited neonatal units.

The Role of Low 25-Hydroxyvitamin D Levels in Preterm Infants with Late-Onset Sepsis

IntroductionWe investigated the association between low 25-hydroxyvitamin D (25-OHD) levels and late-onset sepsis (LOS) in preterm infants (<37 weeks). Methods: Infants with culture-proven LOS were the study group, infants without LOS were the controls. 25-OHD levels were compared between these groups. Low vitamin D was defined as 25-OHD ≤15 ng/ml. Maternal 25-OHD levels were compared to their infant's level. Results: 108 infants were included. The study group was significantly younger (p = 0.02) with significantly lower 25-OHD levels (p < 0.001). Multivariable logistic regression analyses revealed that infants with low 25-OHD levels were 7.159 (95%CI: 1.402-36.553, p = 0.018) times more likely to develop LOS. A positive correlation was detected between maternal and neonatal 25-OHD levels for both study and control groups (r = 0.425, p = 0.009; r = 0.739, p < 0.001, respectively). Conclusions: Low 25-OHD levels are associated with an increased risk of developing LOS development in preterm infants.

Late-onset sepsis in very low birth weight preterm infants: 7 years' experience at a tertiary hospital in China

OBJECTIVE

Studies about the epidemiology and risk factors of late onset of sepsis (LOS) in preterm very low birth weight (PVLBW) infants of developing countries are limited and variable. The objective of this study was to explore the epidemiology, risk factors and pathogens of LOS in VLBW infants in a Chinese tertiary hospital.

METHODS

Data concerning demographies, pathogens, risk factors and outcomes of LOS were collected in a cohort of 710 VLBW infants discharged from January 2012 to December 2018. Chi-square, t-test and multivariable logistic regression analysis were used to identify risk factors.

RESULTS

The overall incidence of LOS was 24.08% and blood culture-proven sepsis was 19.58%. Gram-negative bacteria accounted for 57.93%, and 32.41% of the isolates were Klebsiella pneumoniae. LOS led to a longer hospital stay, higher hospitalization cost and higher mortality compared to infants without LOS. Mortality in Gram-negative or fungi LOS was higher than in Gram-positive LOS. The factor of PVLBW infants with registered permanent residence (PR) was associated with 80% lower likelihood of LOS compared to those without registered PR (P = 0.000, 95% CI 0.096-0.420). Infants with thrombocytopenia had 2.5 times LOS of control (P = 0.014, CI 1.210-5.132). Duration of parenteral nutrition was a risk of LOS (P = 0.009, CI 1.010-1.069).

CONCLUSION

Gram-negative bacteria, especially Klebsiella pneumonia, were the dominant pathogens in this study. Social factors might be a risk of LOS in PVLBW infants in developing countries. Taking measures to reduce the duration of parenteral nutrition may be helpful in decreasing the incidence of LOS. Awareness of thrombocytopenia may help to recognized diagnosis of LOS.

Neonatal sepsis: within and beyond China

Supplemental Digital Content is available in the text

Sepsis remains a significant cause of neonatal morbidity and mortality in China. A better understanding of neonatal sepsis in China as compared with other industrialized and non-industrialized countries may help optimize neonatal health care both regionally and globally. Literature cited in this review was retrieved from PubMed using the keywords “neonatal sepsis,” “early-onset (EOS)” and “late-onset (LOS)” in English, with the focus set on population-based studies. This review provides an updated summary regarding the epidemiology, pathogen profile, infectious work-up, and empirical treatment of neonatal sepsis within and beyond China. The incidence of neonatal EOS and the proportion of Group B Streptococcus (GBS) within pathogens causing EOS in China seem to differ from those in developed countries, possibly due to different population characteristics and intrapartum/postnatal health care strategies. Whether to adopt GBS screening and intrapartum antibiotic prophylaxis in China remains highly debatable. The pathogen profile of LOS in China was shown to be similar to other countries. However, viruses as potential pathogens of neonatal LOS have been underappreciated. Growing antimicrobial resistance in China reflects limitations in adapting antibiotic regimen to local microbial profile and timely cessation of treatment in non-proven bacterial infections. This review stresses that the local epidemiology of neonatal sepsis should be closely monitored in each institution. A prompt and adequate infectious work-up is critically important in diagnosing neonatal sepsis. Adequate and appropriate antibiotic strategies must be overemphasized to prevent the emergence of multi-resistant bacteria in China.

Neonatal Sepsis: A Review of Pathophysiology and Current Management Strategies

BACKGROUND

Early-onset sepsis, occurring within 72 hours of birth, and late-onset sepsis, occurring after this time period, present serious risks for neonates. While culture-based screening and intrapartum antibiotics have decreased the number of early-onset cases, sepsis remains a top cause of neonatal morbidity and mortality in the United States.

PURPOSE

To provide a review of neonatal sepsis by identifying its associated risk factors and most common causative pathogens, reviewing features of the term and preterm neonatal immune systems that increase vulnerability to infection, describing previous and the most current management recommendations, and discussing relevant implications for the neonatal nurse and novice neonatal nurse practitioner.

METHODS/SEARCH STRATEGY

An integrative review of literature was conducted using key words in CINAHL, Google Scholar, and PubMed.

FINDINGS/RESULTS

Group B streptococcus and Escherichia coli are the most common pathogens in early-onset sepsis, while Coagulase-negative staphylococci comprise the majority of cases in late-onset. The neonatal immune system is vulnerable due to characteristics including decreased cellular activity, underdeveloped complement systems, preferential anti-inflammatory responses, and insufficient pathogenic memory. Blood cultures remain the criterion standard of diagnosis, with several other adjunct tests under investigation for clinical use. The recent development of the sepsis calculator has been a useful tool in the management of early-onset cases.

IMPLICATIONS FOR PRACTICE

It is vital to understand the mechanisms behind the neonate's elevated risk for infection and to implement evidence-based management.

IMPLICATIONS FOR RESEARCH

Research needs exist for diagnostic methods that deliver timely and sensitive results. A tool similar to the sepsis calculator does not exist for preterm infants or late-onset sepsis, groups for which antibiotic stewardship is not as well practiced.Video Abstract available athttps://journals.lww.com/advancesinneonatalcare/Pages/videogallery.aspx?autoPlay=false&videoId=40.

Diagnostic Value of Assessment of Serum Cortisol, Hepcidin and Thyroid Hormones Levels in Neonates with Late-Onset Sepsis

Neonatal sepsis is a clinical syndrome characterized by symptoms and signs of infection in the first twenty-eight days of life. Serum thyroid, cortisol and hepcidin are affected by neonatal sepsis. ; Aim of the Work: The aim of this study was to assess the diagnostic value of serum thyroid hormones including free triiodothyronine (free TT3) and free tetraiodothyronine (free TT4), serum cortisol and hepcidin levels through comparison of their concentrations between normal neonates and neonates with high probable late-onset sepsis. ; Patients and Methods: This case-control study was carried out on 40 neonates with suspected high probable late-onset neonatal sepsis based on clinical and laboratory finding who were admitted to NICU of Pediatric Department, Tanta University, Egypt in the period from April 2017 to May 2019 (group I) and 40 healthy neonates matched in age and sex as a control group (group II). For patients and controls, blood culture, highly sensitive C-reactive protein (H-s CRP), serum hepcidin, serum cortisol and thyroid hormones levels including free TT3 and free TT4 were assessed. ; Results: There were no significant differences between studied groups regarding weight, gestational age, sex and mode of delivery. H-s CRP, serum cortisol and hepcidin were significantly higher in group I than group II while serum-free TT3 and free TT4 were significantly lower in group I compared with controls (group II). There was significantly lower H-s CRP, serum hepcidin and cortisol and significantly higher serum-free TT3 and free TT4 in group I after antibiotic therapy compared to the same group before treatment while there were no significant differences between group I after antibiotic therapy and control group (group II) regarding the same parameters. There was a significant positive correlation between H-s CRP and serum hepcidin and cortisol in group I while there was a significant negative correlation between H-s CRP and free TT3 and free TT4. ROC curve of specificity and sensitivity of H-s CRP, serum hepcidin, cortisol, free TT3 and free TT4 in the prediction of neonatal sepsis shows that serum hepcidin had the highest sensitivity and specificity with 95% and 90% respectively followed by serum cortisol, H-s CRP, free TT3 and lastly free TT4. ; Conclusion and Recommendations: Neonates with high probable sepsis had significantly higher serum cortisol and hepcidin and significantly lower free TT3 and free TT4 compared with healthy neonates. These findings may draw our attention about the use of these markers in the diagnosis of neonatal sepsis which can help in early treatment and subsequently better prognosis.

Ralstonia Mannitolilytica, an Unusual Pathogen in the Neonatal Intensive Care Unit: A Case of Neonatal Sepsis and Literature Review

BACKGROUND

Premature infants are considered high-risk subgroup for neonatal sepsis due to yet defective immune system, interventions practised and synergy of factors favoring multiple resistance of Gram-positive and Gram-negative pathogens to antimicrobial agents.

CASE PRESENTATION

We present a case of late-onset neonatal sepsis in a premature infant caused by an uncommon pathogen; a premature infant of extremely low birth weight had in his 4th week of life severe clinical deterioration with lethargy, fever, pallor, mottling, abdominal distention, tachycardia, and worsening respiratory impairment. Full septic screen was performed, broad-spectrum antibiotic therapy was initiated and supportive care per needs was provided. Blood cultures (endotracheal tube tip cultures) isolated meropenem- and gentamicin-resistant strain of rare pathogen Ralstonia mannitolilytica. Ralstonia spp. are aerobic, Gram-negative, lactose non-fermenting, oxidaseand catalase-positive bacilli, thriving in water and soil. Ralstonia spp. are identified only sporadically as causative agents of neonatal sepsis; to our knowledge, this is the second report of neonatal sepsis due to R. mannitolilytica in the literature so far. Our patient was eventually treated (per sensitivity pattern) with intravenous ciprofloxacin and recovered well from the infection.

CONCLUSION

We intend to raise awareness among neonatologists with regard to early detection of unusual pathogens, the emergence of antibiotic resistance patterns, and the obligation for adherence to infection control policies.

Red cell distribution width as a predictor of late-onset Gram-negative sepsis

BACKGROUND

Late-onset sepsis (LOS) remains an important cause of morbidity and mortality in preterm infants. In this study, our aim was to investigate the red-cell distribution width (RDW) levels during a LOS episode, and its association with the type of growing microorganism and mortality.

METHODS

Preterm infants with culture-proven sepsis during their neonatal intensive care unit stay were enrolled. Red-cell distribution width levels were obtained in the first 4 h of postnatal life and at the onset of the LOS episode, and compared for these time frames. The study cohort was divided into two groups according to the type of the growing microorganism. The RDW levels were then assessed in intra- and inter-group analyses.

RESULTS

Eighty-six infants were included in the final analysis. RDW levels were increased in the study cohort after a LOS attack (P < 0.001). Infants with Gram-negative sepsis showed a significant increase in their RDW levels, but they remained unchanged in infants with Gram-positive sepsis (P < 0.001 and P = 0.4, respectively). An RDW cut-off of >19.50% was related with a sensitivity of 87% and a specificity of 81% for predicting late-onset Gram-negative sepsis (P < 0.001). Logistic regression analysis showed a positive association of RDW with mortality when adjusted for covariants (adjusted odds ratio: 1.40; 95% confidence interval: 1.02-1.80; P = 0.03).

CONCLUSIONS

Our findings show that RDW levels increased during a LOS episode in preterm infants, which was especially evident in Gram-negative infections. We believe that these findings may be of importance in the early diagnosis and prognosis of LOS in preterm infants.

Practice variations and rates of late onset sepsis and necrotizing enterocolitis in very preterm born infants, a review

The burden of late onset sepsis (LOS) and necrotizing enterocolitis (NEC) remains high for newborns in low- and high-income countries. Very preterm born infants born below 32 weeks gestation are at highest risk because their immune system is not yet adapted to ex-utero life, providing intensive care frequently compromises their skin or mucosa and they require a long duration of hospital stay. An epidemiological overview is difficult to provide because there is no mutually accepted definition available for either LOS or NEC. LOS incidence proportions are generally reported based on identified blood culture pathogens. However, discordance in minimum day of onset and whether coagulase negative staphylococci or fungi should be included into the reported proportions lead to variation in reported incidences. Complicating the comparison are the absence of biomarkers, ancillary lab tests or prediction models with sufficiently high positive and/or negative predictive values. The only high negative predictive values result from negative blood culture results with negative lab results allowing to discontinue antibiotic treatment. Similar difficulties exist in reporting and diagnosing NEC. Although most publications base their proportions on a modified version of Bell's stage 2 or 3, comparisons are made difficult by the multifactorial nature of the disease reflecting several pathways to intestinal necrosis, the absence of a reliable biomarker and the unclear differentiation from spontaneous intestinal perforations. Comparable reports in very low birthweight infants range between 5% and 30% for LOS and 1.6% to 7.1% for NEC. Evidence based guidelines to support treatment are missing. Treatment for LOS remains largely empirical and focused mainly on antibiotics. In the absence of a clear diagnosis, even unspecific early warning signals need to be met with antibiotic treatment. Cessation after negative blood culture is difficult unless the child was asymptomatic from the beginning. As a result, antibiotics are the most commonly prescribed medications, but unnecessary exposure may result in increased risk for mortality, NEC, further infections and childhood obesity or asthma. Finding ways to limit antibiotic use are thus important and have shown a large potential for improvement of care and limitation of cost. Over recent decades, none of the attempts to establish novel therapies have succeeded. LOS and NEC proportions remained mostly stable. During the past 10 years however, publications emerged reporting a reduction, sometimes by almost 50%. Most concern units participating in a surveillance system using quality improvement strategies to prevent LOS or NEC (e.g., hand hygiene, evidence based "bundles", feeding onset, providing own mother's milk). We conclude that these approaches display a potential for wider spread reduction of LOS and NEC and for a subsequently more successful development of novel therapies as these often address the same pathways as the prevention strategies.

Perinatal Ureaplasma Exposure Is Associated With Increased Risk of Late Onset Sepsis and Imbalanced Inflammation in Preterm Infants and May Add to Lung Injury

Background: Controversy remains concerning the impact of Ureaplasma on preterm neonatal morbidity.

Methods: Prospective single-center study in very low birth weight infants <30 weeks' gestation. Cord blood and initial nasopharyngeal swabs were screened for Ureaplasma parvum and U. urealyticum using culture technique and polymerase chain reaction. Neonatal outcomes were followed until death or discharge. Multi-analyte immunoassay provided cord blood levels of inflammatory markers. Using multivariate regression analyses, perinatal Ureaplasma exposure was evaluated as risk factor for the development of bronchopulmonary dysplasia (BPD), other neonatal morbidities until discharge and systemic inflammation at admission.

Results: 40/103 (39%) infants were positive for Ureaplasma in one or both specimens, with U. parvum being the predominant species. While exposure to Ureaplasma alone was not associated with BPD, we found an increased risk of BPD in Ureaplasma-positive infants ventilated ≥5 days (OR 1.64; 95% CI 0.12–22.98; p = 0.009). Presence of Ureaplasma was associated with a 7-fold risk of late onset sepsis (LOS) (95% CI 1.80–27.39; p = 0.014). Moreover, Ureaplasma-positive infants had higher I/T ratios (b 0.39; 95% CI 0.08–0.71; p = 0.014), increased levels of interleukin (IL)-17 (b 0.16; 95% CI 0.02–0.30; p = 0.025) and matrix metalloproteinase 8 (b 0.77; 95% CI 0.10–1.44; p = 0.020), decreased levels of IL-10 (b −0.77; 95% CI −1.58 to −0.01; p = 0.043) and increased ratios of Tumor necrosis factor-α, IL-8, and IL-17 to anti-inflammatory IL-10 (p = 0.003, p = 0.012, p < 0.001).

Conclusions: Positive Ureaplasma screening was not associated with BPD. However, exposure contributed to BPD in infants ventilated ≥5 days and conferred an increased risk of LOS and imbalanced inflammatory cytokine responses.