S4.1a Fusariosis: MICs, mono versus combination therapy and fosmanogepix

S4.1 TREATMENT OF RARE MOLD INFECTIONS IN 2021: THE ROLE OF NEW AND OLD ANTIFUNGALS, SEPTEMBER 22, 2022, 10:30 AM - 12:00 PM: Fusarium is one of the most clinically prevalent rare molds causing superficial infections such as keratitis in immunocompetent hosts and severe disseminated infections frequently presenting as fungemia in the immunocompromised. These fungi are ubiquitous in nature and are found in soil and air. Only a few of the ˃ 70 Fusarium spp. are opportunistic pathogens in humans. F. solani and F. oxysporum species complexes are specifically important, causing ˃50% and about 20% of severe fusariosis cases, respectively. Although galactomannan and also beta D glucan may result positive in fusariosis, fungal culture from either blood, BAL, or skin biopsy remains the most frequently utilized test for diagnosing fusariosis. Susceptibility testing of isolates recovered in culture should be used for epidemiologic purposes in defining the range of minimal inhibitory concentrations (MIC) distribution of Fusarium spp., however, studies that prove that susceptibility testing results should be utilized to inform antifungal drug choice are lacking. Although there are no interpretive breakpoints for antifungal agents against Fusarium spp., compounds with MICs that are off-scale, such as >16 μg/ml, at the highest range of concentrations are unlikely to be active in vivo or in patients. Initial combination therapy with a lipid formulation of amphotericin B plus voriconazole, deescalated to monotherapy once MICs come back, is, therefore, a frequently chosen management pathway. : A number of drugs in the antifungal pipeline will present additional treatment options for Fusarium, including Fosmanogepix and Olorofim.