Water distribution systems in Sardinian hospitals host invasive clonal lineages of the Fusarium oxysporum and Fusarium solani species complexes

Invasive fusariosis

Invasive fusariosis is a serious invasive fungal disease, affecting immunocompetent and, more frequently, immunocompromised patients. Localized disease is the typical clinical form in immunocompetent patients. Immunocompromised hosts at elevated risk of developing invasive fusariosis are patients with acute leukemia receiving chemotherapeutic regimens for remission induction, and those undergoing allogeneic hematopoietic cell transplant. In this setting, the infection is usually disseminated with positive blood cultures, multiple painful metastatic skin lesions, and lung involvement. Currently available antifungal agents have poor in vitro activity against Fusarium species, but a clear-cut correlation between in vitro activity and clinical effectiveness does not exist. The outcome of invasive fusariosis is largely dependent on the resolution of immunosuppression, especially neutrophil recovery in neutropenic patients.

Invasive fusariosis in acute leukaemia patients-An outbreak in the haematology ward

Fusarium, a common fungus, emerges as a pathogen in severely immunocompromised patients. We present a series of patients who developed invasive fusariosis (IF) during admission to an acute leukaemia ward: an outbreak of 12 cases in June and July 2018, followed by four sporadic cases until 2021. No case was reported earlier. All patients were clustered in the same location with indoor air and water installations found to be contaminated with Fusarium spp. thus a nosocomial outbreak was assumed. Following the water installation replacement, the number of Fusarium cases dramatically dropped to one or two isolated instances per year in the same location. All 16 patients had acute leukaemia and developed IF during severe neutropenia following induction therapy. IF diagnosis was based on positive blood cultures (14 patients) and/or on tissue biopsies (3 patients). The median time from admission to the IF onset was 20 days, and from the first day of severe neutropenia (≤500/mm3) was 11.5 days. All patients were febrile, eight had moderate-to-severe myalgias, eight had respiratory involvements: lung lesions and/or sinusitis and seven had characteristic skin lesions. Follow-up: 12 out of 16 (75%) were alive on Day 90; nine out of 15 (60%) were alive on Month 6. All with intractable neutropenia died. In severely neutropenic febrile patients, the triad of respiratory involvement/skin lesions/severe myalgia may suggest Fusarium aetiology. The ability to recover from neutropenia is critical to surmount IF. The indoor environment in immunocompromised dedicated settings must be constantly controlled.

Invasive Fusariosis in Patients with Hematologic Diseases

Fusarium species are filamentous fungi widely encountered in nature, and may cause invasive disease in patients with hematologic conditions. Patients at higher risk are those with acute leukemia receiving induction remission chemotherapy or allogeneic hematopoietic cell transplant recipients. In these hosts, invasive fusariosis presents typically with disseminated disease, fever, metastatic skin lesions, pneumonia, and positive blood cultures. The prognosis is poor and the outcome is largely dependent on the immune status of the host, with virtually a 100% death rate in persistently neutropenic patients, despite monotherapy or combination antifungal therapy. In this paper, we will review the epidemiology, clinical manifestations, diagnosis, and management of invasive fusariosis affecting patients with hematologic diseases.