No abstract

Most cases of infection with Fusarium spp. fungi involved primary skin lesions.

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.

BackgroundInvasive fusariosis (IF) is a rare but often fatal fungal infection in immunosuppressed patients. In 2007, cases of IF above the expected epidemiologic baseline were detected in the hematology ward of a hospital in Rio de Janeiro, Brazil. Possible sources of infection were investigated by performing environmental sampling and patient isolate collection, followed by molecular typing. Isolates from dermatology patients with superficial fusariosis were included in the study for comparison to molecular types found in the community.MethodsEnvironmental sampling focused on water-related sources in and around the hematology ward. Initially, we characterized 166 clinical and environmental isolates using the Fusarium translation elongation factor 1α (EF-1α) genetic locus. Isolates included 68 collected from water-related sources in the hospital environment, 55 from 18 hematology patients, and 43 from the skin/nails of 40 outpatients seen at the hospital dermatology clinic. Multi-locus sequence typing was performed on Fusarium solani species complex (FSSC) species 1 and 2 isolates to investigate their relatedness further.ResultsMost of the hematology samples were FSSC species 2, with species type FSSC 2-d the most commonly isolated from these patients. Most of the outpatient dermatology samples were also FSSC 2, with type 2-d again predominating. In contrast, environmental isolates from water sources were mostly Fusarium oxysporum species complex (FOSC) and those from air samples mostly Fusarium incarnatum-equiseti species complex (FIESC). A third of the environmental samples were FSSC, with species types FSSC 1-a and FSSC 1-b predominating.ConclusionsFusarium isolate species types from hematology patient infections were highly similar to those recovered from dermatology patients in the community. Four species types (FSSC 1-a, 1-b, 2-d and 2-f) were shared between hematology patients and the environment. Limitations in environmental sampling do not allow for nosocomial sources of infection to be ruled out. Future studies will focus on environmental factors that may have influenced the prevalence of FSSC fusariosis in this hematology ward.