Clinical patterns of Fusarium infections in immunocompromised patients.

Fusarium is an ubiquitous fungus commonly found in soil and on plants. Human infection usually occurs as a result of inoculation of the organism through the body surface, thus causing skin infection, onychomycosis, keratitis, endophthalmitis and arthritis. Dissemination may occur in subjects with underlying immunodeficiency. Among immunocompromised hosts, Fusarium sp. is an emerging pathogen in neutropenic patients. To our knowledge, since 1973, when the first disseminated fusariosis in a child with acute leukemia was reported, about 80 new cases have been reported, mainly occurring in patients with haematologic malignancies. Specific portals of entry are not well understood, nevertheless the respiratory tract, colonised gastrointestinal tract, onychomycosis, disrupted skin barrier and central venous catheter have been reported as entry sites of deep seated Fusarium infections. Fever, positive blood cultures, severe myalgias, disseminated ecthyma gangrenosum-like skin lesions, ocular symptoms and multiple-organ-system involvement are distinctive features in most cases of disseminated fusariosis. The prognosis is very poor with death generally following despite antifungal therapy, unless an increase in the white blood cell count occurs. All available antifungal drugs show a low activity against the various species of Fusarium. Nevertheless, amphotericin B seems to have the highest in vitro activity and, even if it does not appear to be effective in persistently neutropenic patients, it should be currently considered to be the treatment of choice.