Improving survival of vulnerable infants increases neonatal intensive care unit nosocomial infection rate

Evaluating the Use of Neonatal Colonization Screening for Empiric Antibiotic Therapy of Sepsis and Pneumonia

(1) Background: Since 2013, weekly screening for multidrug-resistant Gram-negative (MDRGN) bacteria has been performed in German neonatal intensive care units (NICU). National guidelines recommend considering these colonization analyses for antibiotic treatment regimens. Our retrospective single center study provides insight into the clinical dichotomy of bacterial colonization and infection rates in neonates. (2) Methods: We analyzed microbiological data of neonates admitted to our tertiary level NICU over nine years. Colonization with MDRGN/Serratia marcescens (SERMA) was compared to microbiological findings in sepsis and pneumonia. (3) Results: We analyzed 917 blood and 1799 tracheal aspirate samples. After applying criteria from the Nosocomial Infection Surveillance for Neonates (NEO-KISS), we included 52 and 55 cases of sepsis and pneumonia, respectively; 19.2% of sepsis patients and 34.5% of pneumonia patients had a prior colonization with MDRGN bacteria or SERMA. In these patients, sepsis was not attributable to MDRGN bacteria yet one SERMA, while in pneumonias, ten MDRGN bacteria and one SERMA were identified. We identified late-onset pneumonia and cesarean section as risk factors for MDRGN/SERMA acquisition. (4) Conclusions: Colonization screening is a useful tool for hygiene surveillance. However, our data suggest that consideration of colonization with MDRGN/SERMA might promote extensive use of last resort antibiotics in neonates.

Risk Factors of Nosocomial Infection for Infants in Neonatal Intensive Care Units: A Systematic Review and Meta-Analysis

Background

The aim of this study was to identify the nosocomial infection (NI) risk factors in neonatal Intensive Care Units (NICU).

Material/Methods

Databases (PubMed, Embase, Cochrane, VANFUN, CNKI, and VTTMS) were searched using index words to find relevant studies published before November 2018. Meta-analyses of relative risk (RR) were performed for the identification of risk factors.

Results

Data from 22 cohort studies (2270 infants with and 21 605 infants without NI) were included in the meta-analysis. Infant weight of <2500 g (RR: 3.44, 95% CI: 2.31–5.11), gestational age of <37 weeks (RR: 3.85, 95% CI: 1.87–7.92), mechanical ventilation use (RR: 3.16, 95% CI: 2.21–4.50), venipuncture (RR: 3.01, 95% CI: 1.20–7.57), the incidence of asphyxia (RR: 1.68, 95% CI: 1.04–2.71), and feeding intolerance (RR: 2.12, 95% CI: 1.60–2.81) were identified as the risk factors for the incidence of NI. There was no significant publication bias.

Conclusions

This study shows that <2500 g infant body weight, gestational age of <37 weeks, mechanical ventilation utility, venipuncture, asphyxia incidence, and feeding intolerance are the risk factors for NI nosocomial infection in infants in NICU. Appropriate preventive measures and targeted interventions are needed.

Neonate Bloodstream Infections in Organization for Economic Cooperation and Development Countries: An Update on Epidemiology and Prevention

The term neonatal sepsis is used to describe a generalized bloodstream infection of bacterial, viral, or fungal origin which is associated with hemodynamic changes and other clinical symptoms and signs, however, there is no unified definition. There are no basic criteria regarding differentiation of early-onset sepsis (EOS) versus late-onset sepsis (LOS). Stratification used in studies on neonatal sepsis also rarely includes the general condition of the newborn according to unambiguous assessment at birth, which hampers the establishment of a clear, uniform epidemiological description of neonatal sepsis. We aim to review the published data about the epidemiology and microbiology of sepsis in Organization for Economic Cooperation and Development (OECD) countries. Data was also collected on sepsis prevention programs that can be implemented in neonatal units. The outcomes of interest were incidence or incidence density of EOS and LOS, microbiology of EOS and LOS, and data on the methodology of the research, in particular the criteria for inclusion and exclusion of newborns from the study. Pubmed, EMBASE, LILACS Embase, Scopus, and Google Scholar were used. For the preselection step, inclusion criteria included: "bloodstream infection" or "neonatal sepsis" (MesH), "very low birth weight", and "country" full-text studies, human, and English language. Exclusion criteria included: studies published in languages other than English and studies available only as an abstracts. For proper selection, inclusion criteria included: information about epidemiology or microbiology bloodstream infection (BSI), study population and case definitions, exclusion criteria, narrative reviews, commentaries, case studies, pilot studies, study protocols, pediatric studies, and only clinical data (without microbiology or epidemiology) or studies with only one etiological factor analysis. The data review indicated the lack of an unequivocal, unified definition and no unambiguous basic criteria with regard to differentiation of EOS versus LOS. Among infants <1500 g, studies reported an EOS rate from 7% to 2%. For studies using other definitions (mostly all inborn babies), the rate of EOS ranged from 1% to 3%. The LOS incidences were much more varied among countries; the highest rates were in the multicenter studies focused on very low birth weight (VLBW) infants. The main pathogens in EOS are GBS and Gram-negative bacteria in LOS. Our review data shows that LOS microbiology is very diverse and that Gram-positive cocci, especially staphylococci, predominate versus Gram-negative rods. Unfortunately, the lack of uniform, international prevention programs results in high newborn morbidity and insufficient postnatal prevention of late-onset infections.

[Pathogen distribution, risk factors, and outcomes of nosocomial infection in very premature infants]

OBJECTIVE

To study the pathogen distribution and risk factors of nosocomial infection in very preterm infants, as well as the risk of adverse outcomes.

METHODS

A retrospective analysis was performed for the clinical data of 111 very preterm infants who were born between January and December, 2016 and had a gestational age of <32 weeks and a birth weight of <1 500 g. According to the presence or absence of nosocomial infection after 72 hours of hospitalization, the infants were divided into infection group and non-infection group. The infection group was analyzed in terms of pathogenic bacteria which caused infection and their drug sensitivity. A multivariate logistic regression analysis was used to investigate the potential risk factors and risk of adverse outcomes of nosocomial infection in very preterm infants.

RESULTS

Gram-negative bacteria were the main pathogens for nosocomial infection in very preterm infants and accounted for 54%, among which Pseudomonas aeruginosa was the most common one; the following pathogens were fungi (41%), among which Candida albicans was the most common one. The drug sensitivity test showed that Gram-negative bacteria were highly resistant to β-lactam and carbapenems and highly sensitive to quinolones, while fungi had low sensitivity to itraconazole and high sensitivity to 5-fluorocytosine and amphotericin B. Early-onset sepsis, duration of peripherally inserted central catheter, steroid exposure, and duration of parenteral nutrition were risk factors for nosocomial infection in very preterm infants (P<0.05). Compared with the non-infection group, the infection group had significantly higher risks of pulmonary complications (P<0.05), as well as a significantly longer length of hospital stay and a significantly higher hospital cost (P<0.001).

CONCLUSIONS

Nosocomial infection in very preterm infants is affected by various factors and may increase the risk of adverse outcomes. In clinical practice, reasonable preventive and treatment measures should be taken with reference to drug sensitivity, in order to improve the prognosis of very premature infants.

Reducing ventilator-associated pneumonia in neonatal intensive care unit using "VAP prevention Bundle": a cohort study

BACKGROUND

Ventilator-associated pneumonia (VAP) is a serious health care-associated infection, resulting in high morbidity and mortality. It also prolongs hospital stay and drives up hospital costs. Measures employed in preventing ventilator-associated pneumonia in developing countries are rarely reported. In this study we tried to assess the efficacy of our designed "VAP prevention bundle" in reducing VAP rate in our neonatal intensive care unit (NICU).

METHOD

This prospective before-and-after study was conducted at university hospital NICU, all neonates who had mechanical ventilation for ≥ 48 h were eligible. VAP rates were evaluated before (phase-I) and after (phase-II) full implementation of comprehensive preventive measures specifically designed by our infection control team.

RESULTS

Of 143 mechanically ventilated neonates, 73 patients developed VAP (51%) throughout the study period (2500 mechanical ventilation days). The rate of VAP was significantly reduced from 67.8% (42/62) corresponding to 36.4 VAP episodes/1000 mechanical ventilation days (MV days) in phase-I to 38.2% (31/81) corresponding to 23 VAP/1000 MV days (RR 0.565, 95% confidence interval 0.408-0.782, p = 0.0006) after VAP prevention bundle implementation (phase-II). Parallel significant reduction in MV days/case were documented in post-intervention period (21.50 ± 7.6 days in phase-I versus 10.36 ± 5.2 days in phase-II, p = 0.000). There were a trend toward reduction in NICU length of stay (23.9 ± 10.3 versus 22.8 ± 9.6 days, p = 0.56) and overall mortality (25% versus 17.3%, p = 0.215) between the two phases but didn't reach statistical significance. The commonest micro-organisms isolated throughout the study were gram-negative bacteria (63/66, 95.5%) particularly Klebsilla pneumonia (55/66, 83.4%).

CONCLUSION

Implementation of multifaceted infection control bundle resulted in reduction of VAP rate, length of stay in our NICU.

Infections and risk-adjusted length of stay and hospital mortality in Polish Neonatology Intensive Care Units

BACKGROUND

The objectives of this study were to analyze the impact of infections on prolonging hospital stay with consideration of underlying risk factors and determining the mortality rates and its association with infections.

METHODS

An electronic database developed from a continuous prospective targeted infection surveillance program was used in the study. Data were collected from 2009 to 2012 in five Polish tertiary academic neonatal intensive care units (NICUs). The length of stay (LOS) of 2,003 very low birth weight (VLBW) neonates was calculated as the sum of the number of days since birth until death or until reaching a weight of 1,800g.

RESULTS

The median LOS for neonates with infections was twice as high as for neonates without infection. LOS was significantly affected by the overall general condition of the neonate, as expressed by both gestational age and birth weight as well as by the Clinical Risk Index for Babies (CRIB) score; another independent factor was presence of at least one infection. Risk of in-hospital mortality was significantly increased by male sex and vaginal birth and was lower among breastfed neonates. Deaths were significantly more frequent in neonates without infection.

CONCLUSIONS

The general condition of VLBW infants statistically increase both their risk of mortality and LOS; this is in contrast to the presence of infection, which significantly prolonged LOS only.

Mortality due to bloodstream infections and necrotizing enterocolitis in very low birth weight infants

BACKGROUND

We evaluated the mortality due to nosocomial bloodstream infection (BSI) and necrotizing enterocolitis (NEC) in very low birth weight (VLBW) infants in 229 neonatal departments participating in the German national neonatal infection surveillance system between 2000 and 2011.

METHODS

For each infection type, we conducted a retrospective cohort study and a case-control study. In the cohort studies, the mortality risk due to BSI and/or NEC was estimated by calculating adjusted hazard ratios (AHRs) with 95% confidence intervals (CIs) using Cox proportional hazard regression with time the dependent variable infection. In the matched case-control studies, the attributable mortality was calculated.

RESULTS

A total of 43,116 VLBW infants, of which 6911 patients had at least 1 BSI and 1271 patients had at least 1 NEC, were analyzed. Overall mortality was 6.6%. Patients with at least 1 BSI had a mortality of 5.6%, and patients with at least 1 NEC had a mortality of 19.2%. The cohort studies revealed that BSI (AHR=1.83; 95% CI: 1.61-2.08) and NEC (AHR=6.35; 95% CI: 5.47-7.37) are independently associated with increased mortality. In the case-control study for BSI, 5187 (75.1%) patients with BSI were matched. Attributable mortality was 1.4% (95% CI: 0.7-2.2). In the case-control study for NEC, 1092 (85.9%) patients with NEC were matched. Attributable mortality was 14.7% (95% CI: 12.2-17.1).

CONCLUSIONS

Nosocomial BSI and NEC increased mortality in VLBW infants. BSI, however, was associated with a relatively small attributable mortality of 1.4%, whereas NEC had a high attributable mortality of 14.7%.

Bloodstream infections: epidemiology and resistance

Bloodstream infections in the neonatal intensive care unit (NICU) are associated with many adverse outcomes in infants, including increased length of stay and cost, poor neurodevelopmental outcomes, and death. Attention to the insertion and maintenance of central lines, along with careful review of when the catheters can be safely discontinued, can minimize central-line-associated bloodstream infections rates. Good antibiotic stewardship can further decrease the incidence of bloodstream infections, minimize the emergence of drug-resistant organisms or Candida as pathogens in the NICU, and safeguard the use of currently available antibiotics for future infants.

Surveillance of health care-associated infections in a tertiary hospital neonatal intensive care unit in Egypt: 1-year follow-up

BACKGROUND

Reported rates of neonatal health care-associated infections (HAIs) in neonatal intensive care units (NICUs) have risen rapidly in recent years. Little data are available in Egypt, however. The aim of the present study was to determine the incidence of and risk factors for HAIs in the NICU of Ain Shams University Hospital of Obstetrics and Gynecology.

METHODS

A prospective study was carried out on all neonates admitted in the NICU of Ain Shams University Hospital of Obstetrics and Gynecology in 2012. Centers for Disease Control and Prevention criteria were followed for identifying HAIs.

RESULTS

A total of 434 neonates were enrolled in the study. The cumulative incidence of HAIs in the NICU was 28%. Bloodstream infections accounted for 85% of HAI episodes; pneumonia, for 10%. The most common organism isolated was Klebsiella spp. The main risk factors identified on multivariable analysis were gestational age <38 weeks (relative risk [RR], 1.63), birth weight <1,500 g (RR, 1.39), mechanical ventilation (RR, 1.74), and surgical procedures (RR, 1.65). The mortality rate attributed to HAIs was 11.75%, and the extra hospital length of stay attributed to HAIs was 8 days.

CONCLUSION

The high incidence of HAI identified in the study NICU mandates more vigorous infection control interventions.

Incidence and risk factors of ventriculoperitoneal shunt infections in children: a study of 333 consecutive shunts in 6 years

The major aims of this study were to estimate the infection rate and recognize the risk factor for ventriculoperitoneal (VP) shunt infections in children. To analyze shunt infection rate and identify risk factors, a retrospective cohort analysis of 333 consecutive VP shunt series was performed at Seoul National University Children's Hospital in Korea between January 2005 and February 2011. Overall, 35 shunts (10.5%) were infected, which represented an infection rate of 0.075 infection cases per shunt per year. VP shunt infection occurred at a median of 1 month (range, 6 days to 8 months) after insertion. An independent risk factor for shunt infection was undergoing an operation before the first year of life (relative risk 2.31; 95% confidence interval, 1.19-4.48). The most common causative microorganism was coagulase-negative staphylococci in 16 (45.7%) followed by Staphylococcus aureus in 8 (22.9%). Methicillin resistance rate was 83.3% among coagulase-negative staphylococci and S. aureus. In this study, cerebrospinal fluid shunt infection rate was 10.5%. Infection was frequently caused by methicillin-resistant coagulase-negative staphylococci and S. aureus within two months after shunt surgery. Vancomycin may be considered as the preoperative prophylaxis for shunt surgery in a situation where methicillin resistance rate is very high.

Early-onset infections of very-low-birth-weight infants in Polish neonatal intensive care units

AIM

The objective of this study was to investigate the incidence, causes, the risk factors, etiologic agents and the outcomes of early-onset infections (EOIs) in very-low-birth-weight newborns in Polish neonatal intensive care units.

METHODS

Continuous prospective infection surveillance conducted during 2009 at 6 Polish neonatal intensive care units and included 910 newborns whose birth weight was lower than 1500 g. Infections were defined according to the Gastmeier's criteria. EOIs were diagnosed <3 days after delivery.

RESULTS

The frequency of early-onset septicemia (EOS) was 7.0% and of early-onset pneumonia (EO-pneumonia) 8.6%. The factors significantly increasing the risk of EOS were low gestational age, small birth weight, low score in the Clinical Risk Index for Babies and Apgar score as well as maternal chorioamnionitis. The perinatal prophylaxis did not have an influence on the occurrence of EOS. The factors considerably increasing the risk of EO-pneumonia were low scores in the Clinical Risk Index for Babies and Apgar scores, a low gestational age and bacterial vaginosis in the child's mother during pregnancy. The most important etiologic organisms were Gram-positive cocci (39.7% of all the infections, 47.8% in EOS), Streptococcus agalactiae (20% of the EOS), Gram-negative bacilli (33.3% isolates), yeast-like fungi (isolated in 7.9% of cases) and atypical bacteria (22% of the cases of EO-pneumonia).

CONCLUSIONS

The observed frequency of EOS did not differ from the one described in the literature, whereas the frequency of EO-pneumonia was higher. The bacterial etiologies suggest the vertical transmission of the pathogens and a close relationship between the observed EOIs with maternal environment. The applied perinatal antibiotic prophylaxis was ineffective.

Simple strategies to reduce healthcare associated infections in the neonatal intensive care unit: line, tube, and hand hygiene

This article describes strategies to prevent 2 important healthcare associated infections in the neonatal intensive care unit: central line-associated bloodstream infections and catheter-associated urinary tract infections. Hand hygiene is discussed as the cornerstone for prevention of all healthcare associated infections. Specific recommendations for education and training of health care personnel who insert and maintain central venous catheters and urinary tract catheters are made and best practices for insertion and maintenance of these catheters are discussed. Throughout this article, the emphasis is on prevention of these high morbidity and mortality healthcare associated infections.

Early neutropenia is not associated with an increased rate of nosocomial infection in very low-birth-weight infants

BACKGROUND

Evidence is contradictory whether very low-birth-weight (VLBW, birth weight <1500 g) infants with early neutropenia (NP), especially those born to mothers with preeclampsia experience a greater incidence of nosocomial infection (NI).

OBJECTIVE

To investigate whether NP within the first 7 days of life is a risk factor for NI in VLBW infants.

METHODS

Over a 42-month period, we identified all VLBW infants born at <or=34 weeks gestation who survived for more than 72 h. Infants who had no evidence of early infection, who had at least one complete blood count performed in the first week of life, and who were not given prophylactic recombinant human granulocyte colony-stimulating factor (rhG-CSF) were included in this retrospective study. Early NP was defined as an absolute neutrophil count less than 1500 per microl at any time during the first week of life. NI was defined as the culture of a bacterial or fungal pathogen from a sterile body fluid that was obtained after 72 h of life in an infant with one or more clinical signs of infection.

RESULTS

A total of 338 VLBW infants were reviewed. Of those, 51 infants were excluded because of death or onset of an infection before 72 h of age, lack of a complete blood count in the first week of life or treatment with rhG-CSF. Of the remaining 287 infants, NI occurred in 11 of 77 (14.3%) infants with early NP compared to 42 of 210 (20.0%) infants without early NP (P=0.31). Infants who developed NI were smaller and less mature, had lower Apgar scores, were more frequently instrumented with central lines and required a longer duration of parenteral nutrition compared to infants without NI. Infants with NI also had a higher mortality and a greater incidence of necrotizing enterocolitis, severe intraventricular hemorrhage and threshold retinopathy of prematurity. However, using stepwise multivariate logistic regression analysis, only the duration of parenteral nutrition and gestational age were significant risk factors for NI.

CONCLUSION

Our data do not support the hypothesis that early NP increases the risk for NI in VLBW infants.

Nosocomial infection in neonates: inevitable or preventable?

In the neonatal intensive care unit population the nosocomial infection rate is highest in the lowest-birth-weight infants. It is this group of infants who require the most therapeutic interventions to support them leading to frequent invasive procedures and the longest exposure to the hospital environment. However, infection rates vary from one unit to another, suggesting that there are differences in either how infection rates are determined or the care provided in the various units. This article will describe nosocomial infections and rates in the neonatal intensive care unit and identify strategies of care to minimize the risks of nosocomial infection in low-birth-weight infants.

Incidence of healthcare-associated infections in high-risk neonates: results from the German surveillance system for very-low-birthweight infants

Infants with birthweight <1500g (VLBW) are at high risk of healthcare-associated infection (HAI). We present surveillance data from the NEO-KISS surveillance system, collected between 2000 and 2005 by 52 neonatology departments in Germany. Infants were stratified into two birthweight categories (<1000 and 1000-1499 g), and rates of nosocomial bloodstream infection (BSI), nosocomial pneumonia and necrotising enterocolitis (NEC) were calculated. The data presented comprise 8677 VLBW and 339,972 patient-days. The incidence of bloodstream infection was 6.5 per 1000 patient-days (8.5 and 4.0 according to birthweight category). The incidence of central venous catheter (CVC)-associated BSI was 11.1 per 1000 CVC-days and the incidence of peripheral venous catheter (PVC)-associated BSI was 7.8 per 1000 PVC-days. The incidence of pneumonia was 0.9 per 1000 patient-days (1.3 and 0.4 according to birthweight category). The incidence of pneumonia among intubated patients was 2.7 per 1000 ventilator-days, while the incidence of pneumonia among patients receiving continuous nasel positive airway pressure (CPAP) was 1.0 per 1000 CPAP-days. The incidence of NEC was 0.9 per 1000 patient-days (1.1 and 0.6 according to birthweight category). HAI is frequent among VLBW and shows wide variation between neonatology departments. Preventive strategies to reduce infections in these infants should be prioritised.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Antibiotic regimens for suspected late onset sepsis in newborn infants

BACKGROUND

Late onset neonatal sepsis (systemic infection after 48 hours of age) continues to be a significant cause of morbidity and mortality. Early treatment with antibiotics is essential as infants can deteriorate rapidly. It is not clear which antibiotic regimen is most suitable for initial treatment of suspected late onset sepsis.

OBJECTIVES

To compare the effectiveness and adverse effects of different antibiotic regimens for treatment of suspected late onset sepsis in newborn infants.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used. This includes electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2004), MEDLINE (1966 - Dec 2004), EMBASE (1980 - Dec 2004) and CINAHL (1982 - Dec 2004), electronic abstracts of Pediatric Academic Society meetings (1996 - Dec 2004) and previous reviews including cross references (all articles referenced).

SELECTION CRITERIA

Randomised and quasi randomised controlled trials comparing different initial antibiotic regimens in neonates with suspected late onset sepsis were evaluated.

DATA COLLECTION AND ANALYSIS

Both reviewer authors screened abstracts and papers against the inclusion criteria, appraised the quality of and extracted data from papers. For dichotomous outcomes, treatment effect was expressed as relative risk and risk difference with 95% confidence intervals. NNT was calculated for outcomes for which there was a statistically significant reduction in risk difference.

MAIN RESULTS

Thirteen studies were identified as possibly eligible for inclusion. The majority of studies were excluded as they did not separate data for early and late onset infection. Two studies are still awaiting assessment. Only one small study, in 24 neonates, was included in this review. It compared beta-lactam therapy with a combination of beta lactam plus aminoglycoside. The study did not meet our prespecified criteria for good methodological quality. In babies with suspected infection there was no significant difference in mortality (RR 0.17, 95% CI 0.01 to 3.23) or treatment failure (RR 0.17, 95% CI 0.01 to 3.23). Antibiotic resistance was assessed and there were no cases in either group.

AUTHORS' CONCLUSIONS

There is inadequate evidence from randomised trials in favour of any particular antibiotic regimen for the treatment of suspected late onset neonatal sepsis. The available evidence is not of high quality. Although suspected sepsis and antibiotic use is common, quality research is required to specifically address both narrow and broad spectrum antibiotic use for late onset neonatal sepsis. Future research also needs to assess cost effectiveness and the impact of antibiotics in different settings such as developed or developing countries and lower gestational age groups.

Gram-negative bacilli associated with catheter-associated and non-catheter-associated bloodstream infections and hand carriage by healthcare workers in neonatal intensive care units

OBJECTIVE

Bloodstream infections caused by Gram-negative bacilli are a substantial cause of morbidity and mortality in infants in neonatal intensive care units. This study describes the species of Gram-negative bacilli causing bloodstream infections in two neonatal intensive care units, compares characteristics of catheter-related and non-catheter-related bloodstream infections, and compares species and antibiotic resistance patterns of these organisms with those isolated from the hands of nurses working in the same neonatal intensive care units.

DESIGN

Interventional study.

SETTING

Two high-risk neonatal intensive care units.

PATIENTS

Neonates hospitalized for >or =24 hrs.

INTERVENTIONS

Prospective surveillance for bloodstream infections was performed in two neonatal intensive care units from March 2001 to January 2003. Hand cultures were obtained quarterly from participating nurses immediately after they performed hand hygiene.

MEASUREMENTS AND MAIN RESULTS

There were 298 episodes of bloodstream infections among 2,935 admissions (5.75 episodes per 1,000 patient-days); 77 of 298 (26%) episodes were caused by Gram-negative bacilli. Among these, 47 (61.0%) were catheter-related bloodstream infections (2.61 episodes per 1,000 catheter-days). Eleven and 24 Gram-negative bacilli species were isolated from neonates and nurses, respectively. The most common Gram-negative bacilli causing bloodstream infections were Klebsiella pneumoniae (38.7%), Escherichia coli (21.2%), Enterobacter cloacae (11.2%), and Serratia marcescens (11.2%). In contrast, Acinetobacter lwoffi (18.1%), K. pneumoniae (11.7%), E. cloacae (10.6%), K. oxytoca (10.6%), and Pseudomonas spp. (7.4%) were most commonly isolated from hands of nurses. E. coli, P. aeruginosa, E. cloacae, and E. aerogenes were significantly more likely to cause bloodstream infections than to be isolated from nurses' hands (all p < .001). Although 39% of bloodstream infections were non-catheter-related, there were no significant differences in types of organisms or antimicrobial resistance patterns between catheter-related bloodstream infections and non-catheter-related bloodstream infections (all p > or = .35). Resistance patterns were similar between Gram-negative bacilli isolates from neonates and nurses' hands except for a significantly higher proportion of resistance to cefotaxime and gentamicin among neonatal isolates of K. pneumoniae (p < .05).

CONCLUSIONS

Gram-negative bacilli species isolated from neonatal bloodstream infections and nurses' hands varied significantly. Clean hands of providers are an unlikely source of endemic Gram-negative bacilli, suggesting that prevention strategies should focus more on control of endogenous neonatal flora or environmental sources.

[Epidemiology of nosocomial infections in neonates]

L’épidémiologie des infections nosocomiales chez les nouveau-nés doit, pour être utile, être décrite en tenant compte des définitions (exclusion des infections néonatales précoces) et de la structure de prise en charge. Les nouveau-nés sont soumis au risque nosocomial en maternité (3 % d’infections), en néonatalogie (incidence 7,5 à 12,7 % et densité d’incidence 1,3 à 8,5/1000 jours en niveau I et II) et en réanimation (incidence 14,2 % et densité d’incidence 11,7/1000 jours). Les septicémies à staphylocoque coagulase négative prédominent encore en réanimation mais les gastro-entérites nosocomiales virales sont plus fréquentes en néonatologie. Les facteurs de risque majeurs sont le petit poids, le faible âge gestationnel et la présence d’un cathéter en réanimation, les visites et les épidémies communautaires pour les infections nosocomiales virales.

Nosocomial infection in the NICU: a medical complication or unavoidable problem?

Nosocomial sepsis is a serious problem for neonates who are admitted for intensive care. As it is associated with increases in mortality, morbidity, and prolonged length of hospital stay, both the human and fiscal costs of these infections are high. Although the rate of nosocomial sepsis increases with the degree of both prematurity and low birth weight, no specific lab test has been shown to be very useful in improving our ability to predict who has a "real" blood-stream infection and, therefore, who needs to be treated with a full course of antibiotics. As a result, antibiotic use is double the rate of "proven" sepsis and we are facilitating the growth of resistant organisms in the neonatal intensive care unit. The purpose of this article is to review the topic of nosocomial infections in neonates.

Late-onset infection and the role of antibiotic prescribing policies

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Molecular epidemiology of gram-negative bacilli from infected neonates and health care workers' hands in neonatal intensive care units

We sought to characterize the molecular epidemiology of gram-negative bacilli (GNB) causing infections in infants and associated with carriage on nurses' hands after hand hygiene was performed. From March 2001 to January 2003, GNB caused 192 (34%) of 562 hospital-acquired infections in the 2 participating neonatal intensive care units (NICUs) and were isolated from the hands of 45 (38%) of 119 nurses. Five species--Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens and Enterobacter cloacae, all of which were typed by pulsed-field gel electrophoresis--caused 169 (88%) of 192 of GNB infections. Overall, 58% of infections were caused by unique strains not cultured from other infants or nurses, and 31% of infections were part of unrecognized molecular clusters. In contrast, only 9% of strains that caused infections were cultured from nurses' hands. These data suggest that practices in addition to hand hygiene are needed to prevent horizontal transmission of GNB in the NICU.

Decreasing incidence of neonatal nosocomial bloodstream infections in a neonatal intensive care unit: antenatal corticosteroid treatment an innocent bystander?

We studied the effect of the use of antenatal steroid treatment on the incidence of nosocomial bloodstream infections (NBSI). All episodes of culture proven NBSI occurring after 96 h of hospitalisation were identified retrospectively during a 10-year period (1991-2001). Throughout the study period, the use of antenatal steroids, demographic characteristics and morbidity of the patients were recorded prospectively. Since 1996 more efforts were made to use antenatal steroids to decrease neonatal morbidity and mortality. The incidence rates of NBSI were compared between period 1 (1991-1995) and period 2 (1996-2001). The overall incidence rate of NBSI dropped significantly from 7.4% (6.1%-8.9%) in period 1 to 5.0% (4.0%-6.2%) in period 2 and was most pronounced in the birth weight category 1000 g-1500 g (11.7%, 7.9%-15.0% to 6.9%, 4.3%-10.5%) and 1500 g-2500 g (3.6%, 2.2%-5.6% to 1.4%, 0.6%-2.8%). Antenatal use of steroids increased overall from 19% in 1991 to 51% in 2001 ( P<0.001). Since 1996 there was a decreasing number of ventilation days ( P=0.011) and decreasing incidence of patent ductus arteriosus ( P=0.001), while the incidence of neonatal surgery, chronic lung disease and duration of hospitalisation remained constant over time.

CONCLUSION

increased use of antenatal steroids is associated with a decreasing incidence rate of nosocomial bloodstream infections in neonates with birth weights between 1000 g and 2500 g, probably by decreasing the incidence of patent ductus arteriosus and/or due to improved respiratory outcome. This finding needs to be confirmed by randomised control trials or by a large prospective cohort study in similar population groups.

The role of early enteral nutrition in protecting premature infants from sepsis

Care of critically ill, preterm infants is a major challenge. Because of their small size and complex health problems, preterm infants require long-term hospitalization in the intensive care unit where they are exposed to serious microorganisms and other antigens that can overwhelm their immature immune systems. As smaller and more fragile preterm infants are surviving NICU care, these infants are at increased risk for nosocomial infections. Although modern antimicrobial agents are invaluable in the management of infection, they can result in biologic stress to the immature physiology of the preterm infant. Nonpharmacologic strategies to enhance the immunocompetence of the preterm immune systems provide another alternative in the management of these infants. Because the gastrointestinal tract is one of the largest immune organs within the body, strategies to maximize its immune functions can improve the outcome of these infants and help prevent or minimize the risk of infection. One such strategy is the early introduction of enteral feedings designed to stimulate or prime the gut. Early introduction of enteral feedings in the acutely ill preterm infant appears to be well tolerated in a variety of small clinical studies. Although the studies vary considerably in design and variables measured, collectively they show a solid trend toward improved outcomes. By preventing the negative consequences of a prolonged period of NPO, early enteral feedings promote the normal processes of the gut as a physical, mechanical, physiologic, and immunologic barrier. A solid understanding of the pathophysiology of prolonged NPO status and the physiology of the gut's immune properties enables critical care nurses to improve care of these vulnerable NICU patients.

Molecular typing strategies

Nosocomial infections among infants in neonatal intensive care units are an increasing cause of morbidity and mortality. Efforts to rapidly detect, contain and ultimately prevent cross-transmission of these pathogens require constant vigilance by members of the epidemiology team. A vital component of an epidemiological evaluation is the ability to assess the interrelatedness of clinical isolates. This review focuses on the basic principles, strengths and weaknesses of some of the most commonly used molecular-based procedures, which determine clonal identity of outbreak strains in neonatal settings. Published evidence for the cogent selection of the method best suited for studying a particular organism and technological advances that await the new science of Molecular Epidemiology are also presented. The appropriate use of molecular typing technologies should enable reliable tracking of epidemic clones and thereby enhance the effectiveness of infection control strategies.

Pseudomonas aeruginosa infections in the neonatal intensive care unit

Pseudomonas aeruginosa is a highly adaptable gram-negative bacillus with the ability to cause serious disease in vulnerable populations. This article reviews the relevant epidemiology of this pathogen in the hospital setting with particular attention to the neonatal unit. Issues related to reservoirs of the organism with special consideration of the hands of staff are also addressed. Virulence factors and pathogenic mechanisms are highlighted as well as the important role of antimicrobial resistance patterns. Finally, there is a discussion of the clinical syndromes found in neonates and the appropriate antibiotic usage strategies for effective treatment of this pathogen of continuing importance.

Outbreak investigation in a neonatal intensive care unit

Outbreaks of healthcare-acquired infection can be devastating in neonatal intensive care units. Neonates are especially susceptible hosts because of prematurity of organ systems, low birth weight, and the use of invasive devices. This article outlines methodologies for infection surveillance and recognition of outbreak events. Principles of infection control in the neonatal intensive care unit are reviewed in reference to an outbreak setting, and a multidisciplinary team approach to developing a plan of action to halt the outbreak and find the source is discussed. Epidemiologic methods for determining the geographical extent and timeline of an outbreak, potential reservoirs or a common source of infection are reviewed.

Prevention of nosocomial infections in the neonatal intensive care unit

Nosocomial infections are responsible for significant morbidity and late mortality among neonatal intensive care unit patients. The number of neonatal patients at risk for acquiring nosocomial infections is increasing because of the improved survival of very low birthweight infants and their need for invasive monitoring and supportive care. Effective strategies to prevent nosocomial infection must include continuous monitoring and surveillance of infection rates and distribution of pathogens; strategic nursery design and staffing; emphasis on handwashing compliance; minimizing central venous catheter use and contamination, and prudent use of antimicrobial agents. Educational programs and feedback to nursery personnel improve compliance with infection control programs.