fusariosis fusariosis fusariosis is an infection seen in people with low neutrophils, a type of white blood cell that fights infection. it is a significant opportunistic pathogen in people with blood cancer.: 330 fusariosisspecialtydermatology, infectious diseases risk factorsneutropenia, blood cancerprognosispoor it is associated with infections with fusarium species, such as fusarium proliferatum.it is fatal in more than half of cases.