Acute bacterial meningitis without cerebrospinal fluid pleocytosis in children: results from a nationwide prospective surveillance system between 2001 and 2022.

OBJECTIVES: We aimed to describe cases of acute bacterial meningitis (ABM) without cerebrospinal fluid (CSF) pleocytosis and clinical and biological characteristics of children. METHODS: We analyzed results of a nation-wide population-based prospective surveillance study of acute ABM in children aged 3 months to 15 years in France. Absence of CSF pleocytosis was defined as CSF leukocyte count ≤5/mm. RESULTS WE INCLUDED: 4,754 cases of acute ABM from 2001 to 2022: 173 patients (3.6%) did not have CSF pleocytosis. ABM cases without CSF pleocytosis were mainly related to meningococcus (70% vs 44% with CSF pleocytosis, p<0.001). When performed in CSF with normal leukocyte count, Gram staining was positive for 33%, culture for 80%, PCR results for 41%, and antigen detection for 20% of cases. Case fatality rate was higher for cases without than with CSF pleocytosis (18% vs 6%, p<0.001). On multivariate analysis, absence of CSF pleocytosis was only associated with seizures before hospital arrival (adjusted odds ratio 2.3, 95% confidence interval 1.2-4.6, p<0.01). CONCLUSIONS: ABM without CSF pleocytosis is infrequent but not exceptional, particularly in children with seizures before hospital arrival. Extended vaccination against meningococcus could prevent this clinical form with a high case fatality rate.

Tularemia in Pediatric Patients: A Case Series and Review of the Literature.

BACKGROUND: Unfamiliar to pediatricians, tularemia can lead to delays in diagnosis and hinder appropriate treatment, as its clinical presentation often shares similarities with other more prevalent causes of lymphadenopathy diseases in children. We conducted a comprehensive literature review to offer contemporary insights into the clinical manifestations and treatment strategies for tularemia infection in children. METHODS: Three cases of glandular tularemia were diagnosed in the Pediatric Robert Debré Hospital (Paris) between October 2020 and February 2022. In addition, we conducted a literature search using PubMed in December 2023 of cases of tularemia in children published in English. RESULTS: The 94 cases of the literature review highlight the large age range (from 6 weeks to 17 years) and multiple sources of infection, including diverse zoonotic transmission (86.7%) and contact with contaminated water (13.3%). Fever was a consistent symptom. Ulceroglandular (46.7%), glandular (17%) and oropharyngeal forms (18.1%) predominated. The most frequently used diagnostic method was serology (60.6%). The median time to diagnosis for tularemia was 23.5 days. Hospitalization was required in 63.2% of cases, with a median duration of 4 days. Targeted treatment was based on aminoglycosides (37.6%), fluoroquinolones (30.6%) or tetracyclines (12.9%), in accordance with WHO recommendations, with a mainly favorable outcome, although several cases of meningitis were observed. CONCLUSION: Pediatricians should be aware of the etiology of this febrile lymphadenopathy, notably when experiencing beta-lactam treatment failure, even in young infants, which could help reduce the extra costs associated with inappropriate antibiotic use and hospitalization.

First Isolation of the Heteropathotype Shiga Toxin-Producing and Extra-Intestinal Pathogenic (STEC-ExPEC) E. coli O80:H2 in French Healthy Cattle: Genomic Characterization and Phylogenetic Position.

The emerging heteropathotype shigatoxigenic (STEC) and extra-intestinal pathogenic Escherichia coli (ExPEC) O80:H2 has been the second leading cause of pediatric HUS in France since the mid-2010s. In contrast with other highly pathogenic STEC serotypes, for which ruminants have clearly been identified as the main human infection source, this heteropathotype's reservoir remains unknown. In this context, we describe for the first time the isolation of seven STEC O80:H2 strains from healthy cattle on a single cattle farm in France. This study aimed at (i) characterizing the genome and (ii) investigating the phylogenetic positions of these O80:H2 STEC strains. The virulomes, resistomes, and phylogenetic positions of the seven bovine isolates were investigated using in silico typing tools, antimicrobial susceptibility testing and cgMLST analysis after short-read whole genome sequencing (WGS). One representative isolate (A13P112V1) was also subjected to long-read sequencing. The seven isolates possessed ExPEC-related virulence genes on a pR444_A-like mosaic plasmid, previously described in strain RDEx444 and known to confer multi-drug resistance. All isolates were clonally related and clustered with human clinical strains from France and Switzerland with a range of locus differences of only one to five. In conclusion, our findings suggest that healthy cattle in France could potentially act as a reservoir of the STEC-ExPEC O80:H2 pathotype.

Diagnostic Accuracy of Blind Bronchial Sample Testing by BioFire Pneumonia plus Panel in Pediatric Intensive Care Unit Patients and Its Impact in Early Adaptation of Antimicrobial Therapy: A Prospective Observational Study.

BACKGROUND: Community-acquired and nosocomial lower-respiratory-tract infections in critically ill pediatric patients require early appropriate antibiotic therapy to optimize outcomes. Using blind bronchial samples, we assessed the diagnostic performance of the rapid-multiplex polymerase chain reaction (PCR) assay BioFire Pneumonia plus Panel vs. reference standard culturing with antimicrobial susceptibility testing. METHODS: For this prospective observational study in a single pediatric intensive care unit, we included consecutive patients younger than 18 years admitted for suspected community-, hospital- or ventilator-associated pneumonia in 2021-2022. Sensitivity, specificity, positive predictive value and negative predictive value of the multiplex PCR assay were determined. The kappa coefficient was computed to assess agreement, and univariate analyses were done to identify factors associated with discrepancies between the 2 diagnostic methods. RESULTS: Of the 36 included patients (median age, 1.4 years; interquartile range, 0.2-9.2), 41.7%, 27.8%, and 30.5% had community-, hospital- and ventilator-associated pneumonia, respectively. The overall κ was 0.74, indicating good agreement. Overall, the sensitivity of the multiplex PCR assay was 92% (95% CI: 77%-98%) and specificity 95% (95% CI: 92%-97%), with variations across microorganisms. The median time from sample collection to antimicrobial susceptibility test results was 3.9 (2.5-15) hours with the multiplex PCR assay and 60.5 (47.6-72.2) hours with the reference technique. CONCLUSION: The BioFire Pneumonia plus Panel used to test blind bronchial samples had satisfactory diagnostic performance in critically ill pediatric patients. The rapid results provided by this test may improve the appropriateness of antimicrobial therapy and help minimize the use of antibiotics.

A live attenuated vaccine to prevent severe neonatal Escherichia coli K1 infections.

Preterm birth is currently the leading cause of neonatal morbidity and mortality. Genetic, immunological and infectious causes are suspected. Preterm infants have a higher risk of severe bacterial neonatal infections, most of which are caused by Escherichia coli an in particular E. coli K1strains. Women with history of preterm delivery have a high risk of recurrence and therefore constitute a target population for the development of vaccine against E. coli neonatal infections. Here, we characterize the immunological, microbiological and protective properties of a live attenuated vaccine candidate in adult female mice and their pups against after a challenge by K1 and non-K1 strains of E. coli. Our results show that the E. coli K1 E11 ∆aroA vaccine induces strong immunity, driven by polyclonal bactericidal antibodies. In our model of meningitis, mothers immunized prior to mating transfer maternal antibodies to pups, which protect newborn mice against various K1 and non-K1 strains of E. coli. Given the very high mortality rate and the neurological sequalae associated with neonatal E. coli K1 meningitis, our results constitute preclinical proof of concept for the development of a live attenuated vaccine against severe E. coli infections in women at risk of preterm delivery.

Temocillin for febrile urinary tract infections caused by ESBL-producing Enterobacteriaceae in children: a monocentric exposed/non-exposed study.

OBJECTIVES: To compare the efficacy of temocillin with standard of care (SOC) for treatment of ESBL-producing Enterobacteriaceae (ESBL-E) febrile urinary tract infection (ESBL-E FUTI) in children. METHODS: A monocentric retrospective study of children hospitalized with confirmed ESBL-E FUTI from January 2015 to May 2022 was conducted, comparing clinical cure and a 3 month relapse between two groups of patients: 'exposed' patients (EP) and 'non-exposed' patients (NEP) to temocillin. EP received temocillin for at least 3 days. They were matched (1:1 ratio) on age group, sex and presence of uropathy with NEP who received SOC antibiotic therapy. RESULTS: Thirty-six temocillin-treated children (EP) were matched with 36 SOC children (NEP); 72.2% were under 2 years old (n = 52) and 75.0% had a congenital uropathy (n = 54). EPs had more FUTI history (97.2%, n = 35) than NEPs (61.1%, n = 22) (P < 0.01). Clinical cure rate was 98.6% overall, with no difference between the two groups, as for the FUTI relapse rate, which was 37.1% for EPs versus 27.8% for NEPs (P = 0.45). In bivariate analyses, factors associated with relapses were congenital uropathy (91.3% versus 66.7%, P = 0.04) and subtypes of uropathy, with refluxing uropathy and posterior urethral valves being the more prevalent. Median duration of hospitalization was longer in the EPs (8.0 versus 5.0 days) (P = 0.01). CONCLUSIONS: The high clinical cure rate and comparable outcomes suggest that temocillin may be an effective therapeutic alternative to standard treatment for ESBL-E FUTI in children.

MALDI-MS in first-line screening of newborns for sickle cell disease: results from a prospective study in comparison to HPLC.

OBJECTIVES: Newborn screening (NBS) for sickle cell disease (SCD) requires a robust, high-throughput method to detect hemoglobin S (HbS). Screening for SCD is performed by qualitative methods, such as isoelectric focusing (IEF), and both qualitative and quantitative methods such as high performance liquid chromatography (HPLC), capillary electrophoresis (CE), and tandem mass spectrometry (MS/MS). All these methods detect HbS, as well as low-level or absent HbA, and also other variants of hemoglobin. HPLC is considered as a reference method for NBS, because of its high sensitivity and specificity in detecting HbS. NeoSickle®, a fully automated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) platform, combined with automated sample processing, a laboratory information management system and NeoSickle® software for automatic data interpretation, has increased the throughput of SCD testing. The purpose of this study was to compare the performances of NeoSickle® and HPLC. METHODS: A prospective study was conducted including 9,571 samples from the NBS program to compare MALDI-MS using NeoSickle® with an HPLC method. Correlation between the two methods was studied. For the MALDI-MS method, sensitivity, specificity, NPV, and PPV were calculated. RESULTS: We found over 99.4 % correlation between the HPLC and MALDI-MS results. NeoSickle® showed 100 % of sensitivity and specificity in detecting SCD syndrome, leading to positive and negative predictive values of 100 %. CONCLUSIONS: NeoSickle® is adapted to NBS for SCD, and can be used in first-line high-throughput screening to detect HbS, and beta-thalassemia major warning. When HbS is detected, second-line use of another specific method as HPLC is necessary.

Early-Onset Infection Caused by Escherichia coli Sequence Type 1193 in Late Preterm and Full-Term Neonates.

Using whole-genome sequencing, we characterized Escherichia coli strains causing early-onset sepsis (EOS) in 32 neonatal cases from a 2019-2021 prospective multicenter study in France and compared them to E. coli strains collected from vaginal swab specimens from women in third-trimester gestation. We observed no major differences in phylogenetic groups or virulence profiles between the 2 collections. However, sequence type (ST) analysis showed the presence of 6/32 (19%) ST1193 strains causing EOS, the same frequency as in the highly virulent clonal group ST95. Three ST1193 strains caused meningitis, and 3 harbored extended-spectrum ß-lactamase. No ST1193 strains were isolated from vaginal swab specimens. Emerging ST1193 appears to be highly prevalent, virulent, and antimicrobial resistant in neonates. However, the physiopathology of EOS caused by ST1193 has not yet been elucidated. Clinicians should be aware of the possible presence of E. coli ST1193 in prenatal and neonatal contexts and provide appropriate monitoring and treatment.

Vaccine-preventable Pediatric Acute Bacterial Meningitis in France: A Time Series Analysis of a 19-Year Prospective National Surveillance Network.

BACKGROUND: In France, vaccination has been implemented against Hi serotype b (Hib), pneumococcus with pneumococcal conjugate vaccines (PCV), and Neisseria meningitidis serogroup C (MenC). These interventions with different coverage and uptake have disrupted the epidemiology of vaccine-preventable acute bacterial meningitis (ABM). METHODS: We analyzed data from a French prospective surveillance network of ABM in children ≤15 years old enrolled by 259 pediatric wards (estimated national coverage: 61%). From 2001 to 2020, the effect of vaccine implementation was estimated with segmented linear regression. RESULTS: We analyzed 7,186 cases, mainly due to meningococcus (35.0%), pneumococcus (29.8%), and Hi (3.7%). MenC ABM incidence decreased (-0.12%/month, 95% CI: -0.17 to -0.07, P < 0.001) with no change for the overall meningococcal ABM when comparing the pre-MenC vaccination and the post-MenC vaccination trends. Despite a decreasing MenB ABM incidence without a vaccination program (-0.43%/month, 95% CI: -0.53 to -0.34, P < 0.001), 68.3% of meningococcal ABM involved MenB. No change in pneumococcal ABM incidence was observed after the PCV7 recommendation. By contrast, this incidence significantly decreased after the switch to PCV13 (-0.9%/month, 95% CI: -1.6 to -0.2%, P = 0.01). After May 2014, a rebound occurred (0.5%/month, 95% CI: 0.3-0.8%, P < 0.001), with 89.5% of non-PCV13 vaccine serotypes. Hib ABM incidence increased after June 2017. CONCLUSIONS: PCV7 and MenC vaccine introduction in France, with slow vaccine uptake and low coverage, had no to little impact as compared to the switch from PCV7 to PCV13, which occurred when coverage was optimal. Our data suggest that MenB and next-generation PCVs could prevent a large part of the ABM incidence in France.

Antibiotic Resistance of Haemophilus influenzae in Nasopharyngeal Carriage of Children with Acute Otitis Media and in Middle Ear Fluid from Otorrhea.

Haemophilus influenzae (Hi) is one of the leading bacteria implicated in childhood acute otitis media (AOM). Recent concerns have been raised about the emergence of Hi-resistant strains. We aimed to analyze the evolution of ß-lactam resistance to Hi among strains isolated from nasopharyngeal carriage in children with AOM and in mild ear fluid (MEF) after the spontaneous perforation of the tympanic membrane (SPTM) in France. In this national ambulatory-based cohort study over 16 years, we analyzed the rate of Hi nasopharyngeal carriage and the proportion of ß-lactam-resistant Hi strains over time using a segmented linear regression model. Among the 13,865 children (median [IQR] age, 12.7 [9.3-17.3] months; 7400 [53.4%] male) with AOM included from November 2006 to July 2022, Hi was isolated in 7311 (52.7%) children by nasopharyngeal sampling. The proportion of ß-lactamase-producing and ß-lactamase-negative, ampicillin-resistant (BLNAR) Hi strains in nasopharyngeal carriage remained stable during the study period. Among the 783 children (median [IQR] age, 20 [12.3-37.8] months; 409 [52.2%] male) with SPTM included from October 2015 to July 2022, Hi was isolated in 177 (22.6%) cases by MEF sampling. The proportions of ß-lactamase-producing and BLNAR Hi strains did not significantly differ between nasopharyngeal (17.6% and 8.8%, respectively) and MEF (12.6% and 7.4%) samples. Accordingly, amoxicillin remains a valid recommendation as the first-line drug for AOM in France.

Sporadic Shiga Toxin-Producing Escherichia coli-Associated Pediatric Hemolytic Uremic Syndrome, France, 2012-2021.

Shiga toxin-producing Escherichia coli-associated pediatric hemolytic uremic syndrome (STEC-HUS) remains an important public health risk in France. Cases are primarily sporadic, and geographic heterogeneity has been observed in crude incidence rates. We conducted a retrospective study of 1,255 sporadic pediatric STEC-HUS cases reported during 2012-2021 to describe spatiotemporal dynamics and geographic patterns of higher STEC-HUS risk. Annual case notifications ranged from 109 to 163. Most cases (n = 780 [62%]) were in children <3 years of age. STEC serogroups O26, O80, and O157 accounted for 78% (559/717) of cases with serogroup data. We identified 13 significant space-time clusters and 3 major geographic zones of interest; areas of southeastern France were included in >5 annual space-time clusters. The results of this study have numerous implications for outbreak detection and investigation and research perspectives to improve knowledge of environmental risk factors associated with geographic disparities in STEC-HUS in France.

Diagnostic accuracy of a rapid nucleic acid test for group A streptococcal pharyngitis using saliva samples: protocol for a prospective multicenter study in primary care.

BACKGROUND: Group A streptococcus is found in 20-40% of cases of childhood pharyngitis; the remaining cases are viral. Streptococcal pharyngitis ("strep throat") is usually treated with antibiotics, while these are not indicated in viral cases. Most guidelines recommend relying on a diagnostic test confirming the presence of group A streptococcus before prescribing antibiotics. Conventional first-line tests are rapid antigen detection tests based on throat swabs. Recently, rapid nucleic acid tests were developed; they allow the detection of elements of the genome of group A streptococcus. We hypothesize that these rapid nucleic acid tests are sensitive enough to be performed on saliva samples instead of throat swabs, which could be more convenient in practice. METHODS: This is a multicenter, prospective diagnostic accuracy study evaluating the performance of a rapid nucleic acid test for group A streptococcus (Abbott ID NOW STREP A2) in saliva, compared with a conventional pharyngeal rapid antigen detection test (EXACTO PRO STREPTATEST, lateral flow assay, comparator test), with a composite reference standard of throat culture and group A streptococcus PCR in children with pharyngitis in primary care (i.e., 27 primary care pediatricians or general practitioners). To ensure group A streptococcus is not missed, the salivary rapid nucleic acid test requires a minimally acceptable value of sensitivity (primary outcome) set at 80%. Assuming 35% of participants will have group A streptococcus, we will recruit 800 consecutive children with pharyngitis. Secondary outcomes will include difference in sensitivity between the pharyngeal rapid antigen detection test and the salivary rapid nucleic acid test; variability in sensitivity and specificity of the salivary rapid nucleic acid test with the level of McIsaac score; time to obtain the result of the salivary rapid nucleic acid test; patient, physician, and parents satisfaction; and barriers and facilitators to using rapid tests for group A streptococcus in primary care. ETHICS AND DISSEMINATION: Approved by the Institutional Review Board "Comité de protection des personnes Ile de France I" (no. 2022-A00085-38). Results will be presented at international meetings and disseminated in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov: NCT05521568.

Fatal Meningitis from Shiga Toxin-Producing Escherichia coli in 2 Full-Term Neonates, France.

We report fatal meningitis in 2 neonates in France caused by Shiga toxin 1-producing Escherichia coli. Virulence factors capsular K1 antigen and salmochelin were present in both strains, potentially representing a new hybrid pathotype. Clinicians should remain aware of emerging pathotypes and design therapeutic strategies for neonatal E. coli infections.

Diagnostic Accuracy of Group A Streptococcus Rapid Antigen Detection Test on Middle Ear Fluid in Children With Acute Otitis Media With Spontaneous Perforation: A Prospective Multicenter Evaluation.

Group A Streptococcus is one of the leading causes of otorrhea. The performance of rapid antigen tests in 256 children with otorrhea showed excellent sensitivity, 97.3% (95% confidence interval: 90.7%-99.7%), and specificity, 100% (95% confidence interval: 98.0%-100%). In a period of increasing invasive and noninvasive group A Streptococcus infections, an early diagnosis could be useful.

Dynamics of Antibiotic Resistance of Streptococcus pneumoniae in France: A Pediatric Prospective Nasopharyngeal Carriage Study from 2001 to 2022.

Epidemiological surveillance of nasopharyngeal pneumococcal carriage is important for monitoring serotype distribution and antibiotic resistance, particularly before and after the implementation of pneumococcal conjugate vaccines (PCVs). With a prospective surveillance study in France, we aimed to analyze the dynamics of pneumococcal carriage, antibiotic susceptibility and serotype distribution in children aged 6 to 24 months who had acute otitis media between 2001 and 2022 with a focus on the late PCV13 period from May 2014 to July 2022. Trends were analyzed with segmented linear regression with autoregressive error. For the 17,136 children enrolled, overall pneumococcal carriage was stable during the study. During the late PCV13 period, the five most frequent serotypes were all non-PCV13 serotypes: 15B/C (14.3%), 23B (11.0%), 11A (9.6%), 15A (7.4%) and 35B (6.5%). During the same period, we observed a rebound of penicillin non-susceptibility (+0.15% per month, 95% confidence interval, +0.08 to 0.22, p < 0.001). Five serotypes accounted for 64.4% of the penicillin non-susceptible strains: 11A (17.5%), 35B (14.9%), 15A (13.9%), 15B/C (9.9%) and 19F (8.2%); non-PCV13/PCV15 accounted for <1%, and non-PCV15/PCV20 accounted for 28%. The next generation PCVs, particularly PCV20, may disrupt nasopharyngeal carriage and contribute to decreasing the rate of antibiotic resistance among pneumococci.

Otorrhea bacterial profile, epidemiology before widespread use of the third-generation pneumococcal conjugate vaccine in French children, a prospective study from 2015 to 2023.

OBJECTIVES: The aim of this study was to describe the bacterial profile of middle ear fluid from spontaneous perforation of the tympanic membrane (SPTM) prior to widespread utilization of third- generation pneumococcal conjugate vaccines (PCVs). PATIENTS AND METHODS: From October 2015 to January 2023, children with SPTM were prospectively enrolled by pediatricians. RESULTS: Among the 852 children with SPTM, 73.2% were less than 3 years old; more frequently than older children, they were and suffering from complex acute otitis media (AOM) (27.9%) and conjunctivitis (13.1%). In children under 3 years of age, NT Haemophilus influenzae (49.7%) was the main otopathogen isolated, particularly in those with complex AOM (57.1%). In children over 3 years of age, Group A Streptococcus accounted for 57%. In pneumococcal cases (25.1%), serotype 3 was the main serotype isolated (16.2%), followed by 23B (15.2%). CONCLUSION: Our data from 2015 to 2023 represent a robust baseline preceding the widespread utilization of next-generation PCVs.

Unexpected Increase in Invasive Group A Streptococcal Infections in Children After Respiratory Viruses Outbreak in France: A 15-Year Time-Series Analysis.

In a 15-year pediatric time-series analysis, we showed a rise of invasive Group A streptococcal (iGAS) infections since October 2022, mainly involving pleural empyema, simultaneously to a respiratory virus outbreak. Physicians should be aware of this increased risk of pediatric iGAS infections, especially in settings with intense respiratory viruses' circulation.

Meningitis caused by extended-spectrum ß-lactamase-producing Escherichia coli in infants in France: a case series.

Objectives: We report the first case series focusing on clinical and biological characteristics of meningitis caused by ESBL-producing Escherichia coli in infants. Methods: Between 2001 and 2020, data on all cases of E. coli meningitis were prospectively collected from a network of 259 paediatric wards and 168 microbiology laboratories in France. We analysed the clinical and biological characteristics, short-term complications and long-term sequelae of ESBL-producing E. coli meningitis cases in patients <6 months old. Results: In total, 548 cases of E. coli paediatric meningitis were reported. ESBL-producing E. coli represented 12 (2.2%) cases. We included 10 patients aged <6 months old. Eight (80%) patients presented at least one sign of clinical severity: six needed mechanical ventilation, three presented signs of shock and one was in a coma. The overall short-term prognosis was good, with only one meningitis-attributed death in the first hours of care. All surviving children received carbapenems for a median of 21 days (range 9-28). Two relapses occurred, including one in a patient who received only 14 days of imipenem. We reported no long-term sequelae at a median follow-up of 20 months. Conclusions: Meropenem seems to be the treatment of choice for ESBL-producing E. coli meningitis in children and needs to be given as early as possible (<48 h) and for at least 21 days. Maternal colonization or infection with ESBL-producing Enterobacteriaceae needs to be reported to the neonatal or paediatric ICU team, in order to adapt the empirical antibiotic therapy.

Factors linked to Staphylococcus aureus healthcare-associated infections among pediatric intensive care unit colonized patients.

BACKGROUND: Staphylococcus aureus (SA) is one of the main pathogens responsible for healthcare-associated infection (HCAI) in pediatrics. The aim of this study was to describe the prevalence of SA-HCAI among colonized patients and the factors associated with it in the pediatric intensive care unit (PICU). METHODS: We designed a 6-year retrospective cohort study of a PICU in a French university children's hospital including all children admitted to the PICU from January 1, 2011, to December 31, 2016, who had SA colonization on PICU admission. For each patient, the past medical history and the hospitalization data were collected. HCAIs related to SA were verified according to the criteria of the United States Centers for Disease Control and Prevention. RESULTS: Among all patients colonized with SA (n = 1381, 26%), 105 (8%) had methicillin-resistant SA carriage and 41 (3%) developed an HCAI caused by SA. The main HCAIs were ventilator-associated pneumonia (51%) and central line-associated bloodstream infections (27%). Patients developing HCAI caused by SA had a significantly longer length of hospital stay and a higher mortality rate than the rest of the population. Using a multivariate logistic regression model, the presence of mechanical ventilation, the implementation of a surgical procedure during the PICU stay, and the onset of at least one episode of anemia during the PICU stay were significantly associated with the occurrence of HCAI due to SA. CONCLUSION: HCAIs linked to SA carriage are rare but severe. Mechanical ventilation, surgery during the PICU stay, and anemia are factors associated with SA-HCAI.