Respiratory viral infections are known causes of mortality after allogeneic hematopoietic stem cell transplantation (HSCT). Here, we report a unique case of a child with viral pneumonia caused by coinfection with human metapneumovirus (MPV), respiratory syncytial virus (RSV), and SARS‐CoV‐2 after HSCT. A 9‐year‐old girl with acute lymphoblastic leukemia underwent allogeneic HSCT from a matched, unrelated donor. During the post‐transplant period, in profound leukopenia (below 10 leukocytes/µL), she was diagnosed with SARS‐CoV‐2, MPV, and RSV pneumonia and was treated with ribavirin and chloroquine. Before leukocyte recovery, the girl became asymptomatic, and SARS‐CoV‐2 and RSV clearance was achieved. The shedding of SARS‐CoV‐2 stopped before immune system recovery, and one may hypothesize that the lack of an inflammatory response might have been a contributing factor to the mild clinical course. Post‐transplant care in HSCT recipients with COVID‐19 infection is feasible in regular transplant units, provided the patient does not present with respiratory failure. Early and repeated testing for SARS‐CoV‐2 in post‐transplant patients with concomitant infection mitigation strategies should be considered in children after HSCT who develop fever, respiratory symptoms, and perhaps gastrointestinal symptoms to control the spread of COVID‐19 both in patients and in healthcare workers in hospital environments. Training of staff and the availability of personal protective equipment are crucial for containing SARS‐CoV‐2 infection.

Background. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a lifesaving procedure in malignant and nonmalignant diseases. However, it is associated with a considerable risk of graft-versus-host disease (GvHD). Steroids are a first-line therapy for acute GvHD (aGvHD), but there is no standard treatment for steroid-resistant (SR) gastrointestinal (GI) aGvHD, which has a poor prognosis. The anti-integrin antibody, vedolizumab, could help in controlling SR GI aGvHD symptoms by blocking lymphocyte extravasation and infiltration of the intestinal wall. Objectives. To report the outcomes of 3 children with SR GI aGvHD after allo-HSCT, treated with vedolizumab as the last chance drug. Materials and methods. The study included 3 patients aged from 8 to 10 years who underwent HSCT in Department of Pediatric Bone Marrow Transplantation, Oncology and Hematology at Wroclaw Medical University, Poland, and who developed severe SR GI aGvHD. All patients had grade IV SR aGvHD with GI stage 4 manifestation. Vedolizumab was given as salvage therapy after an ineffective treatment with etanercept, basiliximab, ruxolitinib, extracorporeal photopheresis, and mesenchymal stem cell infusions. Vedolizumab was administered intravenously at a dose of 300 mg. Results. Only 1 patient achieved GvHD remission and was alive and well 9 months after the discontinuation of the therapy. One child developed a relapse of malignant disease and eventually died, and the third child died of severe aGvHD. Conclusions. Vedolizumab can be safely used in children with SR GI aGvHD, offering an additional chance for heavily pretreated patients. Prospective pediatric studies on both prophylactic and therapeutic use of the drug are warranted, according to the preliminary results.

Severe aplastic anemia (SAA) is a bone marrow failure syndrome that can be treated with hematopoietic cell transplantation (HCT) or immunosuppressive (IS) therapy. A retrospective cohort of 56 children with SAA undergoing transplantation with fludarabine–cyclophosphamide–ATG-based conditioning (FluCyATG) was analyzed. The endpoints were overall survival (OS), event-free survival (EFS), cumulative incidence (CI) of graft versus host disease (GVHD) and CI of viral replication. Engraftment was achieved in 53/56 patients, and four patients died (two due to fungal infection, and two of neuroinfection). The median time to neutrophil engraftment was 14 days and to platelet engraftment was 16 days, and median donor chimerism was above 98%. The overall incidence of acute GVHD was 41.5%, and that of grade III-IV acute GVHD was 14.3%. Chronic GVHD was diagnosed in 14.2% of children. The probability of 2-year GVHD-free survival was 76.1%. In the univariate analysis, a higher dose of cyclophosphamide and previous IS therapy were significant risk factors for worse overall survival. Episodes of viral replication occurred in 33/56 (58.9%) patients, but did not influence OS. The main advantages of FluCyATG include early engraftment with a very high level of donor chimerism, high overall survival and a low risk of viral replication after HCT.

Hospital environments host diverse microbial communities that may contribute to nosocomial infections. Moisture-retaining surfaces such as cleaning sponges and faucet edges represent high-contact, under-investigated hygiene hotspots, particularly in wards caring for immunocompromised patients. Environmental samples were collected from cleaning sponges (n = 14) and faucet edges (n = 4) across multiple hospital rooms of a paediatric haematology–oncology unit, with domestic physician sponges as controls (n = 3). DNA was extracted and sequenced targeting the V3–V4 and V7–V9 hypervariable regions of the 16S rRNA gene on the Illumina MiSeq platform. Taxonomic composition and alpha/beta diversity were assessed using QIIME 2 and R. Sponge samples were dominated by Moraxellaceae, particularly Acinetobacter and Enhydrobacter, and showed significantly lower alpha diversity than faucet samples (Shannon index: Kruskal–Wallis H = 8.4, p = 0.01; Faith’s phylogenetic diversity: H = 9.17, p = 0.01). Faucet samples were enriched in human-associated genera including Staphylococcus, Streptococcus, and Chryseobacterium. Statistically significant beta-diversity differences were detected between sponge and faucet communities by PERMANOVA based on Bray–Curtis dissimilarity (p = 0.01), whereas no significant clustering by room or floor location was observed (p = 0.29). Potentially pathogenic taxa including Aeromonas, Pseudomonas, and Enterobacteriaceae were identified across both surface types. Domestic control sponges showed distinct microbiome profiles from hospital samples. Microbial communities differ significantly between hospital sponges and faucets, with surface type rather than location as the primary determinant of community structure. The presence of opportunistic pathogens on both surface types highlights the importance of enhanced hygiene protocols, inclusion of faucet edges and sink drains in routine decontamination schedules, and regular microbiological surveillance in clinical settings caring for immunocompromised patients.