Invasive filamentous fungal disease in critically ill patients has become one of the hardest infectious problems in the intensive care unit. Aspergillus, the Mucorales order and Fusarium account for most cases, and the patients who develop them are no longer only those with low neutrophil counts. The disease is fast, the signs are vague, and the mortality runs from 40 percent to over 80 percent depending on the pathogen. This article explains what the disease is, who is at risk in the ICU, how the diagnosis is built, and how the main antifungal regimens are chosen and adjusted. Quick answer Invasive filamentous fungal disease in critically ill patients is driven…