Airborne transmission of invasive fusariosis in patients with hematologic malignancies

Abstract

From 2006 to 2013, an increasing incidence of fusariosis was observed in the hematologic patients of our University Hospital. We suspected of an environmental source, and the indoor hospital air was investigated as a potential source of the fungemia. Air samplings were performed in the hematology and bone marrow transplant (BMT) wards using an air sampler with pre-defined air volumes. To study the molecular relationship among environmental and clinical isolates, 18 Fusarium spp. recovered from blood cultures were included in the study. DNA sequencing of a partial portion of TEF1α gene was performed for molecular identification. Molecular typing was carried out by multi-locus sequence typing (MLST) using a four-gene scheme: TEF1α, rDNA, RPB1 and RPB2. One hundred four isolates were recovered from the air of the hematology (n = 76) and the BMT (n = 28) wards. Fusarium isolates from the air were from five species complexes: Fusarium fujikuroi (FFSC, n = 56), Fusarium incarnatum-equiseti (FIESC, n = 24), Fusarium solani (FSSC, n = 13), Fusarium chlamydosporum (FCSC, n = 10), and Fusarium oxysporum (FOSC, n = 1). Fifteen Fusarium isolates recovered from blood belonged to FSSC, and three to FFSC. MLST identified the same sequence type (ST) in clinical and environmental isolates. ST1 was found in 5 isolates from blood and in 7 from the air, both identified as FSSC (Fusarium petroliphilum). STn1 was found in one isolate from blood and in one from the air, both identified as FFSC (Fusarium napiforme). F. napiforme was isolated from the air of the hospital room of the patient with fungemia due to F. napiforme. These findings suggested a possible clonal origin of the Fusarium spp. recovered from air and bloodcultures. In conclusion, our study found a diversity of Fusarium species in the air of our hospital, and a possible role of the air as source of systemic fusariosis in our immunocompromised patients.

Molecular identification of Fusarium species complex isolated from clinical samples and its antifungal susceptibility patterns

“…he fungi belonging to the genus Fusarium possess such attributes as the capability to grow on a wide range of substrates and present as biofilms [1] on water and in plumbing systems, setting the ground for the widespread distribution of this fungus [2,3]. These species are well-known plant pathogens [4] that account for the contamination and spoilage of food [5]. More than 300 Fusarium species [6] have been identified, out of which around 70 species are involved in human infections, causing fusariosis [7].…”

“…Some of these species complexes that are commonly implicated in human infections include F. solani species complex (FSSC), F. fujikuroi species complex (FFSC), F. incarnatum-equiseti species complex (FIESC), F. oxysporum species complex (FOSC), F. dimerum species complex (FDSC), F. chlamydosporum species complex (FCSC), and F. tricinctum species complex (FTSC) [7]. The majority of Fusarium infections in immunocompetent individuals are superficial and subcutaneous, while systemic or disseminated infections are seen in immunocompromised individuals [4,15]. Although Fusarium can be identified fairly well morphologically, molecular tests facilitate the accurate identification of the species and their classification in proper species complex [16].…”

Successful management of disseminated Fusarium infection in a patient with acute myeloid leukemia

“…The risk factors for invasive or DFIs include: HMs particularly AML, acute lymphoblastic leukemia (ALL), lymphoma, and multiple myeloma; recipients of HSCT particularly those having GVHD; recipients of solid organ transplantations; solid tumors; human immunode iciency virus patients; drugs such as corticosteroids, immunosuppressive agents and cytotoxic chemotherapy; neutropenia; hyperglycemia; burns; wounds; CVCs; active smoking; blood transfusions; pyoderma gangrenosum; and previous IFI [1,2,5- 7,11,13,14,16,17,18-37]. In patients with HMs who are severely immunocompromised, airborne transmission of invasive fusariosis may occur [38]. The sites of invasive infections caused by Fusarium sp.…”

Bioaerosols and Health: Current Knowledge and Gaps in the Field of Waste Management

“…Bioaerosol inhalation is recognised as one of the main transmission routes for infectious diseases (Eames et al, 2009;Moretti et al, 2018;Qian and Zheng, 2018;Valade et al, 2015;Yates et al, 2016). Infection requires that a micro-organism (bacteria, viruses, fungi) be alive, and the severity of the disease depends on the virulence of the strain and individual risk factors, such as immune deficiency.…”