Risk of catheter-associated bloodstream infection by catheter type in a neonatal intensive care unit: a large cohort study of more than 1100 intravascular catheters.

BACKGROUND: The aim of this study was to evaluate the risk of catheter-associated bloodstream infection (CABSI) among different catheter types using a large prospective database in the neonatal intensive care unit (NICU) of a tertiary care centre in Switzerland. METHODS: We included all neonates admitted to the NICU with at least one central intravascular catheter inserted between January 2017 and December 2020. We used marginal Cox model to determine the risk of CABSI among different catheter types. RESULTS: A total of 574 neonates and 1103 intravascular catheters were included in the study: 581 venous umbilical catheters, 198 arterial umbilical catheters and 324 peripherally inserted central catheters (PICCs). We identified 17, four and four CABSIs in neonates with venous umbilical catheters, arterial umbilical catheters and PICCs, respectively. The risk of CABSI increased after two days of umbilical catheter maintenance. Using univariable Cox models, and adjusting for sex and gestational age, we observed a similar CABSI risk between venous and arterial umbilical catheters (HR 0.57; 95% CI 0.16e2.08). Birth weight was associated with CABSI, with higher weight being protective (HR 0.37, 95% CI 0.16e0.81). CONCLUSIONS: Strategies aimed at reducing umbilical catheter dwell time, particularly in low and very low birth weight neonates, may be effective in decreasing the incidence of CABSI in this population.

[Therapeutic management of neonatal arterial cerebral infarction and neuroprotection perspectives]. / Prise en charge thérapeutique des convulsions associées à l'accident vasculaire cérébral du nouveau-né et perspectives de neuroprotection à la phase aiguë.

Neonatal seizure related to stroke is a common diagnostic feature. Their treatment, although widely debated even today must be initiated in case of status epilepticus, clinical seizures of more than 5 minutes duration or short (> 30 secondes) and repeated clinical seizures (2 or more per hour). The treatment of neonatal seizures is a challenge that remains only partially solved. It should take into account the etiology of seizures, type of brain lesions and clinical/electrical response to treatment after the first line treatment. It is based on using a single anti-epileptic at its maximum dosage, and if needed, on the association with another anti-epileptic drug with a different mechanism of action. Phenobarbital remains the most commonly used drug for initial treatment of neonatal seizures and for which the most clinical experience has been accumulated. The lack of randomized controlled trials makes difficult recommendations about the optimal duration of treatment, but most experts agree that once arrested seizures, the duration of treatment should be as short as possible because of its potential risk on the developing brain. Novel neuroprotective strategies for reducing impact of neonatal stroke or promoting brain repair remain for the moment the concept stage, pre-clinical or parcel clinical data.

[Neonatal arterial ischemic stroke: Review of the current guidelines]. / Accidents vasculaires cérébraux ischémiques artériels néonatals : synthèse des recommandations.

Neonatal arterial ischemic stroke (NAIS) is a rare event that occurs in approximately one in 5000 term or close-to-term infants. Most affected infants will present with seizures. Although a well-recognized clinical entity, many questions remain regarding diagnosis, risk factors, treatment, and follow-up modalities. In the absence of a known pathophysiological mechanism and lack of evidence-based guidelines, only supportive care is currently provided. To address these issues, a French national committee set up by the French Neonatal Society (Société française de néonatologie) and the national referral center (Centre national de référence) for arterial ischemic stroke in children drew up guidelines based on an HAS (Haute Autorité de santé [HAS]; French national authority for health) methodology. The main findings and recommendations established by the study group are: (1) among the risk factors, male sex, primiparity, caesarean section, perinatal hypoxia, and fetal/neonatal infection (mainly bacterial meningitis) seem to be the most frequent. As for guidelines, the study group recommends the following: (1) the transfer of neonates with suspected NAIS to a neonatal intensive care unit with available equipment to establish a reliable diagnosis with MRI imaging and neurophysiological monitoring, preferably by continuous video EEG; (2) acute treatment of suspected infection or other life-threatening processes should be addressed immediately by the primary medical team. Persistent seizures should be treated with a loading dose of phenobarbital 20mg/kg i.v.; (3) MRI of the brain is considered optimal for the diagnosis of NAIS. Diffusion-weighted imaging with apparent diffusion coefficient is considered the most sensitive measure for identifying infarct in the neonatal brain. The location and extent of the lesions are best assessed between 2 and 4 days after the onset of stroke; (4) routine testing for thrombophilia (AT, PC PS deficiency, FV Leiden or FII20210A) or for detecting other biological risk factors such as antiphospholipid antibodies, high FVIII, homocysteinemia, the Lp(a) test, the MTHFR thermolabile variant should not be considered in neonates with NAIS. Testing for FV Leiden can be performed only in case of a documented family history of venous thromboembolic disease. Testing neonates for the presence of antiphospholipid antibodies should be considered only in case of clinical events arguing in favor of antiphospholipid syndrome in the mother; (5) unlike childhood arterial ischemic stroke, NAIS has a low 5-year recurrence rate (approximately 1 %), except in those children with congenital heart disease or multiple genetic thrombophilia. Therefore, initiation of anticoagulation or antithrombotic agents, including heparin products, is not recommended in the newborn without identifiable risk factors; (6) the study group recommends that in case of delayed motor milestones or early handedness, multidisciplinary rehabilitation is recommended as early as possible. Newborns should have physical therapy evaluation and ongoing outpatient follow-up. Given the risk of later-onset cognitive, language, and behavioral disabilities, neuropsychological testing in preschool and at school age is highly recommended.

Varicella outbreak in Sudanese refugees from Calais.

We describe an outbreak of varicella in 31 Sudanese refugees (all except one were male, mean age: 26 ± 1), from the Calais migrant camp and sheltered in a French transit area. The attack rate was 39%. Adults are scantly immunized against varicella zoster virus in East Africa and may be exposed to epidemics once in France.

[Insulin treatment of gestational diabetes and respiratory outcome in late-preterm and term babies]. / Diabète gestationnel traité par insuline et risque de détresse respiratoire sévère chez le nouveau-né de plus de 34 semaines d'aménorrhée.

While the incidence of diabetes mellitus (DM) during pregnancy has been steadily increasing in recent years, the link between gestational DM and respiratory outcome in neonates has not been firmly established. To address this gap in understanding, we asked whether DM status and its treatment during pregnancy influence risk of neonatal respiratory distress. We conducted retrospective analysis of a large cohort to determine the relationship between maternal DM status (non-DM, insulin-treated DM [DTI], and non-insulin-treated DM [DTR]) and respiratory distress in term and near-term singletons, born at Robert-Debré Hospital over a 7-year period. Of 18,095 singletons delivered at 34 weeks of gestation or later, 412 (2.3%) were admitted to the NICU for respiratory distress within the first hours of life. The incidence of NICU admissions due to respiratory distress was 2.2% in the non-DM group, 2.1% in the DTR group, and 5.7% in the DTI group. Insulin treatment of DM, together with several other perinatal factors, was associated with an increased risk for severe respiratory distress. In a multivariate model, we found that DTI, but not DTR, was a risk factor independent of gestational age and cesarean section, with an IRR of 1.44 (95% CI, 1.00-2.08). The data indicate that newborns of mothers with DM treated with diet are not at risk for severe respiratory distress. Conversely, newborns of mothers with DM treated with insulin are associated with elevated risk for severe respiratory disease and should therefore be closely monitored.

Evaluation of the efficacy and tolerance of a short 7 day third-generation cephalosporin treatment in the management of acute pyelonephritis in young women in the emergency department.

OBJECTIVES: Urinary tract infections, among the leading causes of antibiotic prescriptions in adult women, are complicated by increasing antibiotic resistance. Current recommendations propose a 7 day treatment with fluoroquinolones or a 10-14 day course of third-generation cephalosporins (3GC). Our aim was to study the efficiency and tolerance of a short 7 day treatment with 3GC in uncomplicated acute pyelonephritis in women aged between 18 and 65 years. PATIENTS AND METHODS: This study was an open, prospective, non-comparative, monocentric pilot study with consecutive patients. We included women between 18 and 65 years old who had been admitted to the emergency department with a diagnosis of acute pyelonephritis. The treatment consisted of 1 g of ceftriaxone injection followed by 6 days of 400 mg of cefixime per day. The primary endpoint was negative urine cultures on day 9. We opted for Fleming's multistage design for this trial. ClinicalTrials.gov number: NCT01390623. RESULTS: Thirty-seven patients were analysed. The bacteriological response consisted of negative urine cultures for all 37 patients on day 9. On day 9, 30 patients were completely asymptomatic, while 7 exhibited clinical improvement though persistence of bladder irritation or flank pain. On day 37, there were no remaining symptoms and no recurrences of urinary tract infection, as noted during the last follow-up visits. CONCLUSIONS: These results suggest that acute pyelonephritis in women could be successfully treated with a short-term course of 1 g of ceftriaxone on the first day followed by 400 mg of cefixime per day for 6 days. These positive results must be confirmed by a non-inferiority study.

Early Recruitment of Cerebral Microcirculation by Neuronal Nitric Oxide Synthase Inhibition in a Juvenile Ischemic Rat Model.

BACKGROUND: The development of collateral circulation is proposed as an inherent compensatory mechanism to restore impaired blood perfusion after ischemia, at least in the penumbra. We have studied the dynamic macro- and microcirculation after ischemia-reperfusion in the juvenile rat brain and evaluated the impact of neuronal nitric oxide synthase (nNOS) inhibition on the collateral flow. METHODS: Fourteen-day-old (P14) rats were subjected to ischemia-reperfusion and treated with either PBS or 7-nitroindazole (7-NI, an nNOS inhibitor, 25 mg/kg). Arterial blood flow (BF) was measured using 2D-color-coded pulsed ultrasound imaging. Laser speckle contrast (LSC) imaging and sidestream dark-field videomicroscopy were used to measure cortical and microvascular BF, respectively. RESULTS: In basal conditions, 7-NI reduced BF in the internal carotids (by ∼ 25%) and cortical (by ∼ 30%) BF, as compared to PBS. During ischemia, the increased mean BF velocity in the basilar trunk after both PBS and 7-NI demonstrated the establishment of collateral support and patency. Upon re-flow, BF immediately recovered to basal values in the internal carotid arteries under both conditions. The 7-NI group showed increased collateral flow in the penumbral tissue during early re-flow compared to PBS, as shown with both LSC imaging and side-stream dark-field videomicroscopy. The proportion of perfused capillaries was significantly increased under 7-NI as compared to PBS when given before ischemia (67.0 ± 3.9 vs. 46.8 ± 8.8, p < 0.01). Perfused capillaries (63.1 ± 17.7 vs. 81.1 ± 20.7, p < 0.001) and the BF index (2.4 ± 0.6 vs. 1.3 ± 0.1, p < 0.001) significantly increased under 7-NI given at the re-flow onset. CONCLUSIONS: Collateral support in the penumbra is initiated during ischemia, and may be increased during early re-flow by neuronal NOS inhibition (given in pre- and post-treatment), which may preserve brain tissue in juvenile rats.

[Recombinant human erythropoietin in neonates: guidelines for clinical practice from the French Society of Neonatology]. / L'érythropoïétine humaine recombinante chez le nouveau-né : recommandations pour la pratique clinique de la Société française de néonatologie.

OBJECTIVE: 1/To assess the effectiveness and safety of EPO in reducing red blood cell (RBC) transfusions in preterm infants. 2/To provide guidelines for clinical practice in France. METHODS: 1/This systematic evidence review is based on PubMed search, Cochrane library. 2/Using French National Authority for Health methods concerning guidelines for clinical practice. RESULTS: Early EPO reduced the risk of RBC transfusions, donor exposure, and the number of transfusions in very preterm infants (LE2). Late EPO reduced the risk of RBC transfusions and the number of transfusions in very preterm infants (LE2). There is no difference between the effectiveness of early and late EPO (LE2). There is no difference between high-dose and low-dose EPO (LE2). The level of evidence is too low to recommend the intravenous route. EPO has no impact on the rate of bronchopulmonary dysplasia, necrotizing enterocolitis (LE3), and retinopathy of prematurity (LE2). The level of evidence is too low to recommend EPO for neuroprotection in very preterm or term infants. CONCLUSIONS: EPO to reduce RBC transfusion in very preterm infants is recommended (Level A). The optimal time to start therapy is unknown (Level B). The recommended dose is 750IU/kg/week via three subcutaneous injections for 6weeks (Level B).

[Language acquisition in preterm infants during the first year of life]. / Acquisition du langage chez l'enfant prématuré durant la première année de vie.

Previous studies have shown that preterm children are at a higher risk for cognitive and language delays than full-term children. Most of these studies have concentrated on the effects of prematurity during the preschool or school years, while the effect of preterm birth on the early development of language, much of which occurs during the first year of life, remains very little explored. This article focuses on this crucial period and reviews the studies that have explored early phonological and lexical development in preterm infants. The results of these studies show uneven proficiency in different language subdomains in preterm infants. This raises the possibility that different constraints apply to the acquisition of different linguistic subcomponents in this population, in part as a result of a complex interaction between maturation, experience, and language subdomains.

Impaired alveolarization and intra-uterine growth restriction in rats: a postnatal genome-wide analysis.

Intra-uterine growth restriction (IUGR) dramatically increases the risk of bronchopulmonary dysplasia in preterm babies, a disease characterized by arrested alveolarization and abnormal microvascular angiogenesis. We have previously described a rodent low protein diet (LPD) model of IUGR inducing impaired alveolarization, but failed to demonstrate any modification of the classical factors involved in lung development. We performed a genome-wide microarray analysis in 120 rat pups with LPD-induced IUGR and their controls, at three key time points of the alveolarization process: postnatal day 4 (P4): start of alveolarization; P10: peak of the alveolarization process and P21: end of the alveolarization process. Results were analysed using Arraymining, DAVID and KEGG software and validated by qRT-PCR and western blots. Considering a cut-off of 2:1 as significant, 67 transcripts at P4, 102 transcripts at P10 and 451 transcripts at P21 were up-regulated, and 89 transcripts at P4, 25 transcripts at P10 and 585 transcripts at P21 were down-regulated. Automatic functional classification identified three main modified pathways, 'cell adhesion molecules', 'cardiac muscle contraction' and 'peroxisome proliferator-activated receptor' (PPAR). Protein analysis confirmed involvement of the PPAR pathway, with an increase of FABP4, an activator of this pathway, at P4 and an increase of adiponectin at P21. Other data also suggest involvement of the PPAR pathway in impaired alveolarization. Our results show that deregulation of the PPAR pathway may be an important component of the mechanism inducing impaired alveolarization observed in IUGR. The complete dataset is available as GEO profiles on the Gene Expression Omnibus (GEO) database ( www.ncbi.nih.gov/geo/, GEO Accession No. GSE56956).

[Neonatal enterovirus infections reported in France in 2012]. / Infections néonatales à entérovirus en France en 2012.

Enteroviruses (EVs) are among the most common viruses infecting humans. One-third of EV infections affect children under 1 year of age. Neonatal EV infections lead to a wide range of clinical manifestations, from mild febrile illness to severe, potentially fatal sepsis-like conditions with multiorgan failure. EV detections by serotype are reported by the National Reference Centre for EV Infections Lyon on a monthly basis. Demographic, clinical, and biological data were also collected in neonates hospitalized in 2012 for EV infection. Two subgroups were identified according to the beginning of symptoms: until 8 days of life (D8) or strictly after D8. There were 120 neonatal EV infections. Before D8, children with severe infection were born more prematurely with a low birth weight. The EVs most commonly detected in neonates were CV-B4 and E-11. Risk factors for severe EV infections included liver (73% before D8) and hematological damage (thrombocytopenia, 82%; coagulopathy, 64% before D8). This study suggests that systematic serotyping of neonatal EV infections and biological monitoring of liver function could be useful for early identification of children at high risk of clinical severity and fatality.

First outbreak of community-acquired MRSA USA300 in France: failure to suppress prolonged MRSA carriage despite decontamination procedures.

The first French outbreak of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) USA300 clone was investigated. After outbreak investigation, hygiene measures were implemented in all family households and childminders' homes. Several decontamination procedures were performed, which used a combination of topical mupirocin, total body application of chlorhexidine, chlorhexidine gargle (if >6 years old) and a course of antibiotic therapy in cases of infection or decontamination failure. Patients were followed up for MRSA skin and soft tissue infections (SSTIs) and carriage. Strains were characterised by antimicrobial drug resistance profile, pulsed-field gel electrophoresis (PFGE) and DNA microarrays. Between June 2011 and June 2012, six children and six adults among the ten corresponding relatives developed 28 SSTIs. None of the family members, including the index case, had any contact with foreigners or individuals known to have SSTIs. After infection control measures and prolonged decontamination have been implemented with a high adherence, six patients remained sustained CA-MRSA USA300 carriers, including one who developed mupirocin resistance and six who experienced minor CA-MRSA-related SSTIs. A baby was identified as an MRSA carrier 2 months after delivery. CA-MRSA decontamination using mupirocin and chlorhexidine in the community setting may also be a questionable strategy, associated with failure and resistance to both agents. Close monitoring of CA-MRSA SSTIs is required in France and in other European countries where MRSA USA300 has recently emerged. We showed that a closed management based on hygiene measures reinforcement, decolonisation and extended screening may fail to suppress CA-MRSA carriage and subsequent infections.

Early inhaled nitric oxide at high dose enhances rat lung development after birth.

RATIONAL: Inhaled nitric oxide (NO) is frequently administered to full term and preterm newborns in various clinical settings in order to alleviate pulmonary hypertension whilst improving oxygenation. However, the physiological effect of NO on early postnatal lung development has not yet been clearly described. We therefore investigated whether NO administered by inhalation affects lung development at early postnatal life. METHODS: Pregnant rats were placed in a chamber containing 5 ppm (iNO-5 ppm group) and 20 ppm NO (iNO-20 ppm group), started from the last day of their pregnancy in order to keep rat pups under ambient NO from birth to 7 days postnatal. Control animals were kept at room air and all rat pups were sacrificed at postnatal day 7 and day 14. RESULTS: Lung-to-body weight and wet-to-dry lung weight ratios did not significantly differ among 3 groups at postnatal day 7 and day 14. Vascular volume densities (Vv) in both NO groups (5 and 20 ppm) were higher than controls (P<0.05; P<0.001). Pulmonary vessel number was significantly increased in iNO-20 ppm group. Radial alveolar counts (RAC) and mean linear intercepts (MLI) markedly increased (consistent with increased alveolarization) in iNO-20 ppm group. This was associated with upregulation of VEGF/VEGFR-2, MT1-MMP/MMP2 and HO-1 protein expression in iNO-20 ppm group. CONCLUSIONS: We concluded that inhaled NO at 20 ppm enhanced lung development possibly through increased expression of HO-1, VEGF/VEGFR-2, and MMP2 at early stage of postnatal rat life.

[Intrauterine growth retardation and the developing brain]. / Retard de croissance intra-utérin et cerveau en développement.

Fetal growth restriction is the second leading cause of perinatal morbidity and mortality, behind prematurity, and is present in 5-12% of all pregnancies in the general population. Often confused with children constitutionally small for gestational age, those who had not achieved their potential for fetal growth and therefore having true growth restriction can be identified using customized growth curves. The point is to accurately identify fetuses with slowing growth or cessation of growth reflecting a pathological process, because these are at risk of death in utero or chronic fetal hypoxia with a significant impact on brain development. The kinetics of growth and prenatal markers of fetal growth restriction will influence the decision to extract the fetus and the gestational age at birth, as well as other factors involved in the neurodevelopmental outcome. Cognitive deficits and executive, motor, and behavioral dysfunctions described in the short term seem to persist together with greater risk of metabolic syndrome in adulthood. Decisions of fetal extraction by C-section continue to be debated until new epidemiological data will be available on large cohorts monitored over the long term using accurate neurocognitive tools. Understanding the effects of fetal growth restriction on the structure and function of the developing brain is essential for improving the relevance of fetal extraction decisions, perinatal care, and early evaluation of treatments for the prevention of neurodevelopmental disorders.

[Investigation of hospital epidemics and guidelines for the management of suspected cases of measles and invasive meningococcal disease]. / Investigation d'une épidémie hospitalière et règles de prise en charge des cas suspects de rougeole ou d'infection invasive à méningocoque en établissement de soins.

Outbreaks of infectious diseases within healthcare institutions must be detected early and controlled. Hospitals should develop a plan for coordinating all hospital components to respond to these critical situations. The knowledge of the different steps in an outbreak investigation can help identify the source of ongoing outbreaks and prevent additional cases. Outbreak investigation is based on a multidisciplinary approach and is an opportunity for research, training and program considerations.

[Cerebellar injury in premature infants less than 30 weeks of gestation]. / Lésions acquises du cervelet chez le grand prématuré : prévalence, facteurs de risque et conséquences fonctionnelles.

UNLABELLED: Traditionally, the cerebellum has been regarded as a central component of the motor system. Recent studies suggest an important role played by the cerebellum in the development of cognitive and social functions. The objective of this study was to evaluate the incidence of cerebellar injury and to define the obstetrical, neonatal, and radiologic characteristics, as well as the functional outcomes in a population of very preterm infants. METHODS: This retrospective study included neonates born before 30 weeks of gestational age between March 2004 and July 2007. Infants underwent MRI studies at a term-adjusted age; for each preterm infant with cerebellar injury, we identified two infants for the control group with normal MRI, matched on the basis of gestational age. We collected pertinent demographic, prenatal, and acute postnatal data for all infants. Follow-up assessment was performed at 2 years, using the Brunet-Lezine scale. RESULTS: A total of 148 ex-preterm infants were studied. Cerebellar injury was present in 14 (9 %) cases and associated with supratentorial parenchymal injury in 90 %. Duration of ventilation was longer in children with cerebellar injury, compared to controls (19.5 days vs 16.5 days; P=0.03). The other neonatal criteria analyzed were comparable between the two groups. Global developmental, functional, and social-behavioral deficits were more common and profound in preterm infants with cerebellar injury, with no significant difference. CONCLUSION: This study confirms the high incidence of cerebellar injury in very preterm infants and the importance of a specific neurobehavioral follow-up.

[The use of postnatal corticosteroid therapy in premature infants to prevent or treat bronchopulmonary dysplasia: current situation and recommendations]. / Utilisation de la corticothérapie postnatale chez le nouveau-né prématuré dans la prévention et le traitement de la dysplasie bronchopulmonaire : état des lieux et conduite à tenir.

In the last few years, several studies related to the benefit/risk balance of postnatal corticosteroids administered to premature neonates for prevention or treatment of bronchopulmonary dysplasia (BPD) have been published. These data encourage caution, given the risk of long-term adverse neurodevelopmental outcomes. In the meantime, the clinical profile of BPD has been altered based on the progress made in the pre- and postnatal care of premature infants. In 2006, a survey conducted in France in neonatal centers showed that corticosteroids were still frequently used (57% of the centers) following various protocols in very preterm-born infants for respiratory impairment. To promote safer practices and rational use of corticosteroids in the prevention and treatment of BPD in preterm-born neonates, we reviewed the available data in order to establish recommendations. Systemic administration of corticosteroids for prevention or treatment of BPD: (i) should not be used during the first 4 days of life; (ii) is not indicated in the first 3 weeks of life nor (iii) in extubated infants (nasal ventilation or oxygen therapy). The systemic administration of steroids can only be considered after the first 3 weeks of life in very preterm-born ventilator-dependent infants to facilitate extubation (or prevent reintubation related to the severity of BPD). Postnatal dexamethasone administration studied in several randomized clinical trials was shown to have an unfavorable benefit/risk profile, mainly because of the long-term adverse neurocognitive outcomes. Very few studies have been conducted with betamethasone in the postnatal period. According to sparse data, this drug might be as efficacious as dexamethasone, but its long-term risk profile is unknown. It should be noted that following prenatal administration, the benefit/risk profile of betamethasone is better than that of dexamethasone, especially with regard to neurocognitive development. Intravenous hydrocortisone administered at an early stage for the prevention of BPD is being evaluated and should not be administered in this indication, except within clinical trials approved by the ethics committee. No other corticosteroids have been evaluated in the postnatal period in respiratory indications. In conclusion, in the situations described above for which systemic corticosteroids could be justified, the use of betamethasone (or hydrocortisone) appears to be better. As usual, the lowest possible dose of corticosteroids should be administered for the shortest possible duration. The betamethasone-equivalent dose of 0.125 mg/kg/day for 3 days is deemed adequate. If inhaled, corticosteroid therapy may facilitate extubation. Neither its efficacy in respiratory diseases nor its long-term risk profile has been so far established.

Multidrug-resistant Klebsiella pneumoniae outbreak after endoscopic retrograde cholangiopancreatography.

BACKGROUND AND STUDY AIMS: Infection is a recognized complication of endoscopic retrograde cholangiopancreatography (ERCP). We describe the epidemiologic and molecular investigations of an outbreak of ERCP-related severe nosocomial infection due to KLEBSIELLA PNEUMONIAE producing extended-spectrum beta-lactamase (ESBL). PATIENTS AND METHODS: We conducted epidemiologic and molecular investigations to identify the source of the outbreak in patients undergoing ERCP. We carried out reviews of the medical and endoscopic charts and microbiological data, practice audits, surveillance cultures of duodenoscopes and environmental sites, and molecular typing of clinical and environmental isolates. RESULTS: Between December 2008 and August 2009, 16 patients were identified post-ERCP with KLEBSIELLA PNEUMONIAE that produced extended-spectrum beta-lactamase type CTX-M-15. There were 8 bloodstream infections, 4 biliary tract infections, and 4 cases of fecal carriage. The microorganism was isolated only from patients who had undergone ERCP. Environmental investigations found no contamination of the washer-disinfectors or the surfaces of the endoscopy rooms. Routine surveillance cultures of endoscopes were repeatedly negative during the outbreak but the epidemic strain was finally isolated from one duodenoscope by flushing and brushing the channels. Molecular typing confirmed the identity of the clinical and environmental strains. Practice audits showed that manual cleaning and drying before storage were insufficient. Strict adherence to reprocessing procedures ended the outbreak. CONCLUSIONS: The endoscopes used for ERCP can act as a reservoir for the emerging ESBL-producing K. PNEUMONIAE. Regular audits to ensure rigorous application of cleaning, high-level disinfection, and drying steps are crucial to avoid contamination.