Nirsevimab Effectiveness Against Cases of Respiratory Syncytial Virus Bronchiolitis Hospitalised in Paediatric Intensive Care Units in France, September 2023-January 2024.

In September 2023, France was one of the first countries that started a national immunisation campaign with nirsevimab, a new monoclonal antibody against respiratory syncytial virus (RSV). Using data from a network of paediatric intensive care units (PICUs), we aimed to estimate nirsevimab effectiveness against severe cases of RSV bronchiolitis in France. We conducted a case-control study based on the test-negative design and included 288 infants reported by 20 PICUs. We estimated nirsevimab effectiveness at 75.9% (48.5-88.7) in the main analysis and 80.6% (61.6-90.3) and 80.4% (61.7-89.9) in two sensitivity analyses. These real-world estimates confirmed the efficacy observed in clinical studies.

Elevated monocyte HLA-DR in pediatric secondary hemophagocytic lymphohistiocytosis: a retrospective study.

Introduction: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition, and its diagnosis may be challenging. In particular, some cases show close similarities to sepsis (fever, organ failure, and high ferritin), but their treatment, while urgent, differ: prompt broad-spectrum antibiotherapy for sepsis and immunosuppressive treatment for HLH. We questioned whether monocyte human leucocyte antigen (mHLA)-DR could be a diagnostic marker for secondary HLH (sHLH). Methods: We retrospectively reviewed data from patients with a sHLH diagnosis and mHLA-DR quantification. mHLA-DR data from healthy children and children with septic shock, whose HLA-DR expression is reduced, from a previously published study were also included for comparison. Results: Six patients with sHLH had mHLA-DR quantification. The median level of monocyte mHLA-DR expression in patients with sHLH [79,409 antibodies bound per cell (AB/C), interquartile range (IQR) (75,734-86,453)] was significantly higher than that in healthy children and those with septic shock (29,668 AB/C, IQR (24,335-39,199), and 7,493 AB/C, IQR (3,758-14,659), respectively). Each patient with sHLH had a mHLA-DR higher than our laboratory normal values. Four patients had a second mHLA-DR sampling 2 to 4 days after the initial analysis and treatment initiation with high-dose corticosteroids; for all patients, mHLA-DR decreased to within or close to the normal range. One patient with systemic juvenile idiopathic arthritis had repeated mHLA-DR measurements over a 200-day period during which she underwent four HLH episodes. mHLA-DR increased during relapses and normalized after treatment incrementation. Conclusion: In this small series, mHLA-DR was systematically elevated in patients with sHLH. Elevated mHLA-DR could contribute to sHLH diagnosis and help earlier distinction with septic shock.

Central-line-associated bloodstream infections in a pediatric oncology and hematology hospital at home program.

OBJECTIVE: Central-line-associated bloodstream infections (CLABSIs) are associated with significant morbidity among pediatric oncology-hematology patients, and risk factors remain largely unknown in the setting of hospital at home (HAH). Children in HAH receive intensive treatment (eg, chemotherapy and parenteral nutrition), with frequent central-line handling; thus, they may be at higher risk for CLABSI. METHODS: We conducted a monocentric retrospective study of patients with a central line included in our HAH program from January 1 to December 31, 2016. HAH patient characteristics for children developing CLABSIs were compared to those who did not, based on blood cultures positive for infection and clinical data of all patients included. RESULTS: Overall, 492 HAH stays were analyzed, with 144 patients. The overall CLABSI rate in these patients was 2.6 per 1,000 central-line days. Children who developed CLABSIs were younger (median age, 2.5 vs 8.8 years; P < .001), suffered more from hematological pathologies (malignant or nonmalignant, 75% vs 52%; P = .02), and had more frequently undergone hematopoietic stem-cell transplantation (30.8% vs 6.5%; P = .01). In addition, these patients often had a tunneled externalized catheter as the central line and were more frequently given parenteral nutrition at home (46% vs 8%; P < .001). CONCLUSIONS: CLABSI rates for children in HAH were more similar to those of inpatients than to rates previously reported for ambulatory patients. The factors associated with infection identified herein should be further validated in multicentric studies and considered to improve HAH practices, parallel to prevention measures used in the inpatient setting.