fusariosis

Fusariosis is an infection caused by Fusarium species, a group of ubiquitous hyaline molds found in soil, plants, and water. In humans, fusariosis ranges from localized, superficial disease such as keratitis and cutaneous lesions to invasive disseminated infection, particularly in individuals with impaired immune function.

Fusarium infections occur worldwide but are more common in tropical and subtropical climates. Risk factors include severe neutropenia, hematologic malignancies, solid organ or stem cell transplantation, prolonged corticosteroid or immunosuppressive therapy, and exposure to environmental sources such as soil or plant material, including ocular trauma or contact lens use.

Clinical manifestations vary by site and host status. Localized cutaneous disease may follow trauma and present as necrotic eschars or ulcerations. Keratitis is a notable presentation, especially among contact lens wearers. Respiratory or sinus involvement can occur, and disseminated fusariosis may present with fungemia and multifocal organ involvement in severely immunocompromised patients.

Diagnosis relies on microbiological methods. Fungal cultures from blood, tissue, or sterile sites typically grow Fusarium spp. Microscopy shows hyaline, septate hyphae and characteristic multicellular, boat-shaped macroconidia. Molecular methods and species-level identification by PCR can aid in diagnosis and epidemiologic tracking.

Treatment is challenging due to variable antifungal susceptibility. Liposomal amphotericin B or voriconazole is commonly used, with posaconazole or combination therapy considered in some cases. Management also includes addressing immunosuppression when possible and, for localized infections such as keratitis or soft-tissue lesions, surgical debridement or topical therapy as appropriate.

Prognosis is poor for disseminated fusariosis, especially in neutropenic patients, while localized infections have a better outlook with timely therapy. Prevention focuses on minimizing exposure to environmental sources and meticulous wound and eye care, particularly in high-risk individuals.