Epidemiology and trends of necrotizing enterocolitis in Sweden: 1987-2009

Single-Immunoglobulin Interleukin-1-Related Receptor regulates vulnerability to TLR4-mediated necrotizing enterocolitis in a mouse model

BackgroundThe mechanisms underlying aberrant activation of intestinal Toll-like receptor 4 (TLR4) signaling in necrotizing enterocolitis (NEC) remain unclear. In this study, we examined the role of single-immunoglobulin interleukin-1 receptor-related molecule (SIGIRR), an inhibitor of TLR signaling, in modulating experimental NEC vulnerability in mice.MethodsExperimental NEC was induced in neonatal wild-type and SIGIRR-/- mice using hypoxia, formula-feeding, and lipopolysaccharide administration. Intestinal TLR canonical signaling, inflammation, apoptosis, and severity of experimental NEC were examined at baseline and after NEC induction in mice.ResultsSIGIRR is developmentally regulated in the neonatal intestine with a restricted expression after birth and a gradual increase by day 8. At baseline, breast-fed SIGIRR-/- mouse pups exhibited low-grade inflammation and TLR pathway activation compared with SIGIRR+/+ pups. With experimental NEC, SIGIRR-/- mice had significantly more intestinal interleukin (IL)-1β, KC (mouse homolog to IL-8), intercellular adhesion molecule-1 (ICAM-1), and interferon-beta (IFN-β) expression in association with the amplified TLR pathway activation. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining, cleaved caspase 3, and severity of intestinal injury with NEC were worse in SIGIRR-/- mice in comparison with SIGIRR+/+ mice.ConclusionSIGIRR is a negative regulator of TLR4 signaling in the developing intestine, and its insufficiency results in native intestinal TLR hyper-responsiveness conducive to the development of severe experimental NEC in mice.

Pediatric Chronic Intestinal Failure in Italy: Report from the 2016 Survey on Behalf of Italian Society for Gastroenterology, Hepatology and Nutrition (SIGENP)

Background: Intestinal failure (IF) is the reduction in functioning gut mass below the minimal level necessary for adequate digestion and absorption of nutrients and fluids for weight maintenance in adults or for growth in children. There is a paucity of epidemiologic data on pediatric IF. The purpose of this study was to determine the prevalence, incidence, regional distribution and underlying diagnosis of pediatric chronic IF (CIF) requiring home parenteral nutrition (HPN) in Italy. Methods: Local investigators were selected in 19 Italian centers either of reference for pediatric HPN or having pediatric gastroenterologists or surgeons on staff and already collaborating with the Italian Society for Pediatric Gastroenterology, Hepatology and Nutrition with regard to IF. Data requested in this survey for children at home on Parenteral Nutrition (PN) on 1 December 2016 included patient initials, year of birth, gender, family’s place of residence and underlying diagnosis determining IF. Results: We recorded 145 CIF patients on HPN aged ≤19 years. The overall prevalence was 14.12/million inhabitants (95% CI: 9.20–18.93); the overall incidence was 1.41/million inhabitant years (95% CI: 0.53–2.20). Conclusion: Our survey provides new epidemiological data on pediatric CIF in Italy; these data may be quantitatively useful in developing IF care strategy plans in all developed countries.

Infections following surgical patent ductus arteriosus ligation in very-low-birthweight neonates

BACKGROUND

Very-low-birthweight (VLBW) neonates (<1500g) comprise approximately 1% of liveborn infants in Poland. Patent ductus arteriosus (PDA) is a common complication of prematurity. This study aimed to determine how many VLBW neonates treated in the participating units needed surgical correction of PDA, and to evaluate the incidence of various types of postoperative infections and their microbiology.

METHODS

Observational study in five neonatology departments by the Polish Neonatology Surveillance Network, involving 2039 VLBW newborns of whom 103 (5.1%) required surgical PDA ligation. Continuous infection surveillance was conducted between 2009 and 2013; infections were defined based on Gastmeier's criteria.

RESULTS

PDA surgery was required significantly more frequently in infants from multiple pregnancies, and where labour was complicated by amnionitis. Surgical PDA correction was performed, on average, at 19 days of life. The incidence of infection was 48.5% (N = 50), and the most common infections were bloodstream infection (26.2%) and pneumonia (22.3%). A correlation was observed between the day on which the procedure was performed and the time of infection: the earlier the neonate underwent PDA surgery, the earlier the infection manifested (P = 0.032). A high CRIB score and chorioamnionitis contributed significantly to the presence of infection.

CONCLUSION

The later the PDA surgery was performed, the later the infection occurred. The incidence of infection after correction of PDA among VLBW neonates was comparable with the incidence of infection among all hospitalized VLBW neonates.

Population-based study showed that necrotising enterocolitis occurred in space-time clusters with a decreasing secular trend in Sweden

Aim

This study investigated space–time clustering of neonatal necrotising enterocolitis over three decades.

Methods

Space–time clustering analyses objects that are grouped by a specific place and time. The Knox test and Kulldorff's scan statistic were used to analyse space–time clusters in 808 children diagnosed with necrotising enterocolitis in a national cohort of 2 389 681 children born between 1987 and 2009 in Sweden. The municipality the mother lived in and the delivery hospital defined closeness in space and the time between when the cases were born – seven, 14 and 21 days – defined closeness in time.

Results

The Knox test showed no indication of space–time clustering at the residential level, but clear indications at the hospital level in all the time windows: seven days (p = 0.026), 14 days (p = 0.010) and 21 days (p = 0.004). Significant clustering at the hospital level was found during 1987–1997, but not during 1998–2009. Kulldorff's scan statistic found seven significant clusters at the hospital level.

Conclusion

Space–time clustering was found at the hospital but not residential level, suggesting a contagious environmental effect after delivery, but not in the prenatal period. The decrease in clustering over time may reflect improved routines to minimise the risk of contagion between patients receiving neonatal care.

Risk Factors for Necrotizing Enterocolitis in Neonates: A Retrospective Case-Control Study

BACKGROUND

Necrotizing enterocolitis (NEC) in neonates is devastating, and risk-factor identification is crucial. This study aimed to evaluate risk factors for NEC in different gestational age (GA) groups.

METHODS

Risk factors associated with NEC were investigated using a retrospective case-control design. Patients with Bell's Stage NEC≥II were divided into three groups based on GA: I, <34 weeks; II, ≥34 weeks but <37 weeks; III, ≥37 weeks. Each case was paired with two GA- and weight-matched controls. Data were collected from medical records, and univariate and conditional logistic regression analyses employed.

RESULTS

A total of 238 cases and 476 controls were enrolled. Variation in the months when NEC was diagnosed was noted, with a peak in January and a trough in August. Intrahepatic cholestasis of pregnancy and transfusion with packed red blood cells were significantly associated with NEC in preterm infants. Meconium aspiration syndrome was an independent risk factor for a greater chance of NEC development in full-term infants. Postnatal asphyxia and sepsis were associated with an increased risk of NEC in all groups. Probiotic use was associated with a reduced risk of NEC. Patients aged >34 weeks with congenital heart disease were more likely than controls to have NEC.

CONCLUSION

Intrahepatic cholestasis of pregnancy and meconium aspiration syndrome may be new risk factors for NEC.

Necrotizing enterocolitis symposium: Epidemiology and early diagnosis

Despite decades of research on necrotizing enterocolitis (NEC), the outlook for infants afflicted by this devastating disease is all too often bleak. The aim of this symposium at the BAPS conference in Amsterdam was to highlight recent advances in the knowledge of the epidemiology and diagnosis of NEC. There were important contributions on the disease in the United Kingdom, both from a neonatal and from a surgical point of view, whereas colleagues from the Netherlands and elsewhere in Europe shared their insights into novel diagnostic tools, both biofluid and imaging based.

LEVEL OF EVIDENCE

Level V.

Current Research on the Epidemiology, Pathogenesis, and Management of Necrotizing Enterocolitis

Despite decades of research on necrotizing enterocolitis, we still do not fully understand the pathogenesis of the disease, or how to prevent or how to treat it. However, as a result of recent significant advances in the microbiology, molecular biology, and cell biology of the intestine of preterm infants and infants with necrotizing enterocolitis, there is some hope that research into this devastating disease will yield some important translation into effective prevention, more rapid diagnosis, and novel therapies.

Incidence and enteral feed antecedents of severe neonatal necrotising enterocolitis across neonatal networks in England, 2012-13: a whole-population surveillance study

BACKGROUND

Necrotising enterocolitis is a neonatal gastrointestinal inflammatory disease with high mortality and severe morbidity. This disorder is growing in global relevance as birth rates and survival of babies with low gestational age improve. Population data are scant and pathogenesis is incompletely understood, but enteral feed exposures are believed to affect risk. We aimed to quantify the national incidence of severe necrotising enterocolitis, describe variation across neonatal networks, and investigate enteral feeding-related antecedents of severe necrotising enterocolitis.

METHODS

We undertook a 2-year national surveillance study (the UK Neonatal Collaborative Necrotising Enterocolitis [UKNC-NEC] Study) of babies born in England to quantify the burden of severe or fatal necrotising enterocolitis confirmed by laparotomy, leading to death, or both. Data on all liveborn babies admitted to neonatal units between Jan 1, 2012, and Dec 31, 2013, were obtained from the National Neonatal Research Database. In the subgroup of babies born before a gestational age of 32 weeks, we did a propensity score analysis of the effect of feeding in the first 14 postnatal days with own mother's milk, with or without human donor milk and avoidance of bovine-origin formula, or milk fortifier, on the risk of developing necrotising enterocolitis.

FINDINGS

During the study period, 118 073 babies were admitted to 163 neonatal units across 23 networks, of whom 14 678 were born before a gestational age of 32 weeks. Overall, 531 (0·4%) babies developed severe necrotising enterocolitis, of whom 247 (46·5%) died (139 after laparotomy). 462 (3·2%) of 14 678 babies born before a gestational age of 32 weeks developed severe necrotising enterocolitis, of whom 222 (48·1%) died. Among babies born before a gestational age of 32 weeks, the adjusted network incidence of necrotising enterocolitis ranged from 2·51% (95% CI 1·13-3·60) to 3·85% (2·37-5·33), with no unusual variation from the adjusted national incidence of 3·13% (2·85-3·42), despite variation in feeding practices. The absolute risk difference for babies born before a gestational age of 32 weeks who received their own mother's milk within 7 days of birth was -0·88% (95% CI -1·15 to -0·61; relative risk 0·69, 95% CI 0·60 to 0·78; number needed to treat to prevent one case of necrotising enterocolitis 114, 95% CI 87 to 136). For babies who received no compared with any bovine-origin products within 14 days of birth, the absolute risk difference was -0·65% (-1·01 to -0·29; relative risk 0·61, 0·39 to 0·83; number needed to treat 154, 99 to 345). We were unable to assess the effect of human donor milk as use was low.

INTERPRETATION

Early feeding of babies with their own mother's milk and avoidance of bovine-origin products might reduce the risk of necrotising enterocolitis, but the absolute reduction is small. Owing to the rarity of severe necrotising enterocolitis, international collaborations are needed for adequately powered preventive trials.

FUNDING

National Institute for Health Research.

Necrotising enterocolitis and mortality in preterm infants after introduction of probiotics: a quasi-experimental study

Evidence on the clinical effectiveness of probiotics in the prevention of necrotising enterocolitis (NEC) in preterm infants is conflicting and cohort studies lacked adjustment for time trend and feeding type. This study investigated the association between the introduction of routine probiotics (Lactobacillus acidophilus and Bifidobacterium bifidum; Infloran(®)) on the primary outcome 'NEC or death'. Preterm infants (gestational age <32 weeks or birth weight <1500 gram) admitted before (Jan 2008-Sep 2012; n = 1288) and after (Oct 2012-Dec 2014; n = 673) introduction of probiotics were compared. Interrupted time series logistic regression models were adjusted for confounders, effect modification by feeding type, seasonality and underlying temporal trends. Unadjusted and adjusted analyses showed no difference in 'NEC or death' between the two periods. The overall incidence of NEC declined from 7.8% to 5.1% (OR 0.63, 95% CI 0.42-0.93, p = 0.02), which was not statistically significant in the adjusted models. Introduction of probiotics was associated with a reduced adjusted odds for 'NEC or sepsis or death' in exclusively breastmilk-fed infants (OR 0.43, 95% CI 0.21-0.93, p = 0.03) only. We conclude that introduction of probiotics was not associated with a reduction in 'NEC or death' and that type of feeding seems to modify the effects of probiotics.

Bowel Perforation in Premature Infants with Necrotizing Enterocolitis: Risk Factors and Outcomes

We aim to determine risk factors and clinical outcomes for bowel perforation in premature infants with NEC. We analyzed clinical data of 57 cases of premature infants with NEC at our NICU between January 2010 and December 2012. Based on the presence of bowel perforation, we divided these infants into two groups: perforated NEC group (n = 10) and nonperforated NEC group (n = 47). We compared general information, clinical characteristics, and laboratory findings between groups. The perforated NEC group, compared to the nonperforated NEC group, had significantly lesser gestational age, lower birth weight, higher prevalence of apnea, mechanical ventilation, sepsis and shock, lower blood pH, higher levels of blood glucose, abnormal WBC count and thrombocytopenia, and elevated CRP (all P < 0.05). Moreover, the perforated NEC group had significantly longer durations of fasting and TPN usage, higher incidences of EUGR and cholestasis, longer duration of antibiotics, higher frequency of advanced antibiotics use, and poorer prognosis than the nonperforated NEC group (all P < 0.05). Bowel perforation in premature infants with NEC was associated with multiple risk factors. Early identification of some of these risk factors in premature infants with NEC may help implement early intervention to reduce the incidence of bowel perforation and thereby improve the prognosis.

Short- and Long-Term Outcomes for Extremely Preterm Infants

Prematurity is the leading cause of infant mortality worldwide. In developed countries, extremely preterm infants contribute disproportionately to both neonatal and infant mortality. Survival of this high-risk population has incrementally improved in recent years. Despite these improvements, approximately one in four extremely preterm infants dies during the birth hospitalization. Among those who survive, respiratory and other morbidities are common, although their effect on quality of life is variable. In addition, long-term neurodevelopmental impairment is a large concern for patients, clinicians, and families. However, the interplay of multiple factors contributes to neurodevelopmental impairment, with measures that change over time and outcomes that can be difficult to define and predict. Understanding outcomes of extremely preterm infants can help better counsel families regarding antenatal and postnatal care and guide strategies to improve survival without morbidity. This review summarizes recent evidence to provide an overview into the short- and long-term outcomes for extremely preterm infants.

Working group reports: evaluation of the evidence to support practice guidelines for nutritional care of preterm infants-the Pre-B Project

The "Evaluation of the Evidence to Support Practice Guidelines for the Nutritional Care of Preterm Infants: The Pre-B Project" is the first phase in a process to present the current state of knowledge and to support the development of evidence-informed guidance for the nutritional care of preterm and high-risk newborn infants. The future systematic reviews that will ultimately provide the underpinning for guideline development will be conducted by the Academy of Nutrition and Dietetics' Evidence Analysis Library (EAL). To accomplish the objectives of this first phase, the Pre-B Project organizers established 4 working groups (WGs) to address the following themes: 1) nutrient specifications for preterm infants, 2) clinical and practical issues in enteral feeding of preterm infants, 3) gastrointestinal and surgical issues, and 4) current standards of infant feeding. Each WG was asked to 1) develop a series of topics relevant to their respective themes, 2) identify questions for which there is sufficient evidence to support a systematic review process conducted by the EAL, and 3) develop a research agenda to address priority gaps in our understanding of the role of nutrition in health and development of preterm/neonatal intensive care unit infants. This article is a summary of the reports from the 4 Pre-B WGs.

Impacts of β-estradiol on intestinal injury in newborn rats

OBJECTIVE

Necrotizing enterocolitis has been investigated and debated extensively in recent years; however, there is still no effective treatment. The aim of this study was thus to examine the effects of β-estradiol on intestinal injury in rats.

METHODS

Twenty-four newborn female rat pups were divided into three groups. In group 1 (sham), hypoxia-re-oxygenation was not performed. In group 2 (saline), the rats were injected with saline after hypoxia-re-oxygenation, and the process was repeated for 5 d. In group 3 (β-estradiol treatment), the rats were subjected to hypoxia-re-oxygenation and then given β-estradiol intraperitoneally once a day for 5 d. After these procedures, the terminal ileum was removed for analysis.

RESULTS

Statistically significant differences in histological grades were found between groups 1 and 2 (p = 0.000), groups 1 and 3 (p = 0.028), and groups 2 and 3 (p = 0.021). There were also differences in TNF-α and IL-6 levels between groups 2 and 3 (p = 0.000 and p = 0.038, respectively) and between groups 1 and 2 (p = 0.000 and p = 0.000); there was no difference between groups 1 and 3 (p = 0.574 and p = 0.195, respectively). Electron microscopy examination revealed a decrease in lipid droplets at the apical cytoplasm of the columnar cells in group 2; in group 3, the absorption of the lipids as lipid droplets was similar to that of group 1.

CONCLUSION

In this study, β-estradiol was found to decrease the intensity of intestinal injury significantly by inhibiting TNF-α and IL-6.

Trends in infant mortality rates in Hungary between 1963 and 2012

AIM

This study investigated annual and seasonal death trends for infants of <1 year of age in Hungary between 1963 and 2012 and analysed commonly accepted risk factors.

METHODS

Data on the numbers of live births and infant deaths were obtained from the published nationwide population register. Negative binomial regression was applied to investigate the yearly trends in rates and also the effect of possible risk factors - low birthweight, maternal education and sex - on infant mortality. Cyclic trends were investigated using logistic regression.

RESULTS

Annual infant mortality declined significantly (p < 0.001) from 42.9 to 4.9 per 1000 live births per year during the study period and significantly increased (p < 0.001) in the low birthweight group and lower maternal education groups. A significant (p < 0.001) cyclic trend in mortality was revealed, with a peak in deaths in late February for all infants and a double peak, in May and November, in the group of cases who died during the early neonatal period.

CONCLUSION

This Hungarian study suggests that there was a significant seasonal effect on neonatal and infant mortality at the end of winter between 1963 and 2012. We speculate that this may have been related to respiratory infections.

Necrotizing enterocolitis: a clinical review on diagnostic biomarkers and the role of the intestinal microbiota

Necrotizing enterocolitis (NEC) remains one of the most frequent gastrointestinal diseases in the neonatal intensive care unit, with a continuing unacceptable high mortality and morbidity rates. Up to 20% to 40% of infants with NEC will need surgical intervention at some point. Although the exact pathophysiology is not yet elucidated, prematurity, use of formula feeding, and an altered intestinal microbiota are supposed to induce an inflammatory response of the immature intestine. The clinical picture of NEC has been well described. However, an early diagnosis and differentiation against sepsis is challenging. Besides, it is difficult to timely identify NEC cases that will deteriorate and need surgical intervention. This may interfere with the most optimal treatment of infants with NEC. In this review, we discuss the pathogenesis, diagnosis, and treatment of NEC with a focus on the role of microbiota in the development of NEC. An overview of different clinical prediction models and biomarkers is given. Some of these are promising tools for accurate diagnosis of NEC and selection of appropriate therapy.

Causes and timing of death in extremely premature infants from 2000 through 2011

BACKGROUND

Understanding the causes and timing of death in extremely premature infants may guide research efforts and inform the counseling of families.

METHODS

We analyzed prospectively collected data on 6075 deaths among 22,248 live births, with gestational ages of 22 0/7 to 28 6/7 weeks, among infants born in study hospitals within the National Institute of Child Health and Human Development Neonatal Research Network. We compared overall and cause-specific in-hospital mortality across three periods from 2000 through 2011, with adjustment for baseline differences.

RESULTS

The number of deaths per 1000 live births was 275 (95% confidence interval [CI], 264 to 285) from 2000 through 2003 and 285 (95% CI, 275 to 295) from 2004 through 2007; the number decreased to 258 (95% CI, 248 to 268) in the 2008-2011 period (P=0.003 for the comparison across three periods). There were fewer pulmonary-related deaths attributed to the respiratory distress syndrome and bronchopulmonary dysplasia in 2008-2011 than in 2000-2003 and 2004-2007 (68 [95% CI, 63 to 74] vs. 83 [95% CI, 77 to 90] and 84 [95% CI, 78 to 90] per 1000 live births, respectively; P=0.002). Similarly, in 2008-2011, as compared with 2000-2003, there were decreases in deaths attributed to immaturity (P=0.05) and deaths complicated by infection (P=0.04) or central nervous system injury (P<0.001); however, there were increases in deaths attributed to necrotizing enterocolitis (30 [95% CI, 27 to 34] vs. 23 [95% CI, 20 to 27], P=0.03). Overall, 40.4% of deaths occurred within 12 hours after birth, and 17.3% occurred after 28 days.

CONCLUSIONS

We found that from 2000 through 2011, overall mortality declined among extremely premature infants. Deaths related to pulmonary causes, immaturity, infection, and central nervous system injury decreased, while necrotizing enterocolitis-related deaths increased. (Funded by the National Institutes of Health.).

Probiotics and necrotizing enterocolitis

One of the most controversial areas in neonatology is whether probiotics should be provided routinely to preterm infants to prevent necrotizing enterocolitis (NEC). This review provides the reader with a brief overview of NEC and current concepts of its pathophysiology, discusses the microbial ecology of the intestine in preterm infants and factors that may lead to a "dysbiosis", summarizes studies of probiotics in preterm infants, elaborates on the need for regulation in this area, and discusses alternatives to probiotics and what is the future for the prevention of NEC.

Risk factors for necrotising enterocolitis in an HIV-endemic region

BACKGROUND

Several risk factors have been implicated in the development of necrotising enterocolitis (NEC). However, little has been reported on the risk factors for NEC in infants born in a setting where exposure to maternal human immunodeficiency virus (HIV) is prevalent.

OBJECTIVES

To determine maternal and infant characteristics associated with NEC in a setting with a high prevalence of HIV infection and to compare clinical presentation and mortality of NEC in HIV-exposed and unexposed infants.

METHODS

This was a retrospective, case-control study. Infants with a confirmed diagnosis of NEC, admitted between January 2005 and December 2008 were identified as cases. Two controls for each case were selected by matching them for birthweight, gestational age and date of birth. Hospital records were reviewed for maternal and infant characteristics.

RESULTS

One hundred and ten infants with confirmed NEC were identified and 220 were selected as controls. Median birthweight and gestational age were similar between cases and controls, (1370 and 1380 g, P = 0·96, and 31 weeks each, P = 0·62, respectively). Lack of use of antenatal corticosteroids (ANS) (OR 2·77, 95% CI 1·42-5·38, P = 0·003), presence of chorio-amnionitis (OR 7·28, 95% CI 2·16-24·51, P = 0·001) and not mechanically ventilated at birth (OR 3·54, 95% CI 1·29-9·69, P = 0·01) were independently associated with NEC. Maternal HIV status was not associated with NEC. Clinical presentation and mortality from NEC were similar between HIV-exposed and unexposed infants.

CONCLUSIONS

Infants who develop NEC were less likely to have received mechanical ventilation at birth, suggesting that they were less critically ill when born. Use of ANS should be encouraged as it is protective against NEC. Infants born to HIV-infected mothers were not at increased risk of NEC.

Necrotizing enterocolitis: the mystery goes on

Necrotizing enterocolitis (NEC) has largely been present in neonatal intensive care units for the past 60 years. NEC prevalence has corresponded with the continued development and sophistication of neonatal intensive care. Despite major efforts towards its eradication, NEC has persisted and appears to be increasing in some centers. The pathophysiology of this disease remains poorly understood. Several issues have hampered our quest to develop a better understanding of this disease. These include the fact that what we have historically termed 'NEC' appears to be several different diseases. Animal models that are commonly used to study NEC pathophysiology and treatment do not directly reflect the most common form of the disease seen in human infants. The pathophysiology appears to be multifactorial, reflecting several different pathways to intestinal necrosis with different inciting factors. Spontaneous intestinal perforations, ischemic bowel disease secondary to cardiac anomalies as well as other entities that are clearly different from the most common form of NEC seen in preterm infants have been put into the same database. Here I describe some of the different forms of what has been called NEC and make some comments on its pathophysiology, where available studies suggest involvement of genetic factors, intestinal immaturity, hemodynamic instability, inflammation and a dysbiotic microbial ecology. Currently utilized approaches for the diagnosis of NEC are presented and innovative technologies for the development of diagnostic and predictive biomarkers are described. Predictions for future strategies are also discussed.