Fusarium

Background

Macroscopic: colonies grow rapidly with wooly texture (sometimes mucoid), and white, yellow, pink, purple, or pale brown surface and pale, red, violet, brown, or blue reverse.
Microscopic: septate hyaline hyphae. Microconidia are unicellular (sometimes bicellular) and hyaline, ovoid to ellipsoid, in chains or singly from denticles. Macroconidia are curved and multicellular, with a foot cell at the base. Chlamydospores may be present.
- The macroconidia are the typical finding used to identify Fusarium spp.
Species of medical importance include:
- F. solani: most common overall, and a common cause of keratitis
- F. oxysporum: second-most common
- F. verticillioides: third-most common
- F. moniliforme
- F. proliferatum
- F. chlamydosporum
- F. anthophilum
- F. dimerum
- F. sacchari

Ubiquitous, common in soil and organic debris, and a common cause of disease in plants.
In humans, infection is rare and generally occurs after penetrating trauma.
Disseminated and CNS disease is more common in immunocompromised hosts, including prolonged neutropenia.

Superficial
- Keratitis and endophthalmitis: big outbreak associated with contact lens solution back in the day
- Onychomycosis
- Skin and musculoskeletal infections (including mycetoma)
Locally invasive
- Pneumonia
- Peritonitis associated with peritoneal dialysis
- Brain abscess
Disseminated infection
- Fungemia: can be detected in blood culture
- Disseminated infection

Remove indwelling lines, if possble
Treat underlying immunocompromise, if possible
Amphotericin B (high dose) is the antifungal of choice, although voriconazole and posaconazole have also been used
Some species are inherently resistant to amphotericin, so may need to treat with combination amphotericin and voriconazole until susceptibilities are available