Epidemiology of nosocomial acquisition of Candida lusitaniae

Candida species are important nosocomial pathogens; however, little is known about the epidemiology of Candida lusitaniae, an organism frequently resistant to amphotericin B. We evaluated 98 patients admitted to the bone marrow transplant and medical intensive care units of a tertiary-care hospital. Each patient with C. lusitaniae was matched with control patients. Restriction fragment analysis of DNA was used to determine strain relatedness. Seven patients (7.1%) with C. lusitaniae were identified; five acquired C. lusitaniae after admission to the study unit. All isolates were susceptible to amphotericin B. There were no differences between patients and controls with regard to duration of stay in the study unit, antibiotic administration, antifungal therapy, immunosuppressive therapy, catheter use, or underlying disease. Temporal and geographic clustering of five patients with identical strains occurred. No common source was identified. Restriction fragment analysis revealed a total of eight strains, and five patients shared one strain type. These results demonstrate exogenous acquisition of C. lusitaniae. The mechanism of acquisition is probably indirect contact transmission between patients.