Fusariosis in immunocompromised pediatric patients: results of a single-center study

Over the past two decades, the incidence of rare invasive mycoses, including fusariosis, has increased. Fusariosis remains diagnostically challenging and is associated with high mortality. Here, we present the results of a retrospective-prospective single-center study conducted between 01.01.2013 and 01.11.2025 at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of the Russian Federation. The study aimed to evaluate the clinical characteristics, diagnostic performance, and treatment outcomes of immunocompromised children with fusariosis. It included 16 patients (10 males and 6 females), the median age was 11.5 years (range 2.5–16.0). Hematological malignancies were present in 70% of the cases; primary immunodeficiency, aplastic anemia, osteosarcoma, and systemic lupus erythematosus were less common. Fusariosis developed after chemotherapy (n = 9), hematopoietic stem cell transplantation (n = 4), or immunosuppressive therapy (n = 3). The major risk factors included severe neutropenia and corticosteroid use (87.5%). Disseminated disease occurred in 50% of the patients, localized fusariosis was diagnosed in 40% of the patients, and isolated fungemia was reported in one case. The most frequently affected sites were skin/soft tissues (50%), paranasal sinuses (50%), and lungs (43.75%). Parenchymal organs, bones and eyes were involved less often. The main pathogens were Fusarium solani (n = 6) and Fusarium proliferatum (n = 5), followed by Fusarium oxysporum, Fusarium verticilioides, and Fusarium petroliphilum. Seven patients developed invasive fungal co-infections with Aspergillus flavus (n = 4), Rhizopus spp. (n = 1), Scedosporium aurantiacum (n = 1) and Candida glabrata (n = 1) which was associated with increased mortality. First-line therapy included lipid formulations of amphotericin B (81%) and voriconazole (56%); combination therapy was used in 62.5% of the cases. Fourteen patients achieved a rapid partial response (the median time to response was 21 days), which correlated with favorable outcomes: all these patients were cured and had significantly higher overall survival. In the entire cohort, the 6-week survival was 81%, the overall survival was 69%. The study demonstrated the effectiveness of timely diagnosis and specific therapy for invasive fusariosis in the most vulnerable category of immunocompromised children.