Pseudallescheria boydii (Anamorph Scedosporium apiospermum) Infection in Solid Organ Transplant Recipients in a Tertiary Medical Center and Review of the Literature

Abstract

Scedosporium apiospermum (Sca) is a ubiquitous filamentous fungus capable of causing invasive disease. We reviewed our electronic microbiology records and the English-language literature. Between 1976 and December 1999 we identified 23 solid organ transplant recipients with Sca infection, 7 of which occurred between December 1987 and December 1999 at our institution. Overall incidence was 1 per 1,000 patients, with a trend of higher incidence in patients receiving lung transplants compared with other transplant organs (p = 0.06). The 23 patients included liver (4), kidney (8), heart (8), lung (2), and heart/lung (1) recipients. Male to female ratio was 19:4, and the mean age was 46 ± 12 (SD) years. Fungal infection was diag-nosed at a median of 4 months (range, 0.4–156 mo) after transplant. The clinical presentation included disseminated disease (8), skin lesions (3), lung disease (5), endophthalmitis (1), meningitis (1), brain abscess with or without extension to eye (3), fungal mycotic aneurysm (1), and sinusitis (1). Seven (30%) patients had intravascular infection, and 11 (48%) patients had central nervous system involvement. Antifungal therapy was accompanied by surgical debridement in 9 cases. Three additional patients were found to have airway colonization only and received itraconazole prophylaxis, without evidence of disease. Of 22 patients with known outcome, 16 (72.7%) died. Five of 6 patients who survived had localized infections: skin lesions (n = 3), sinus fungus ball (n = 1), and solitary lung nodule (n = 1). All patients with disseminated disease and 10 of 11 patients with central nervous system disease died. An exception was 1 patient with a brain abscess, successfully treated with voriconazole and surgical drainage. Sca infection is rare but is associated with high mortality. Early diagnosis by culture is important because Sca is resistant to amphotericin B, routinely used in the empiric therapy of invasive fungal infections. Treatment with the combination of an antifungal and surgery may have a better outcome. Voriconazole promises to be an effective antifungal agent. Cultures positive for Sca should not be ignored, and long-term antifungal prophylaxis in candidates and transplant recipients should be considered.