Clinical characteristics, microbiology, and outcomes for patients with lung and disseminated nocardiosis in a tertiary hospital

Abstract

Nocardia are ubiquitous in the environment worldwide and cause a variety of infections. Clinical manifestations and outcomes of nocardiosis can vary with different populations, host immunity, and presentations. The purpose of this study was to analyze the differences in clinical characteristics, antimicrobial susceptibility, and outcomes for patients with skin, lung, and disseminated nocardiosis. We conducted a retrospective survey of culture-proven nocardial infections in 81 patients with invasive nocardiosis over an 18-year period at the National Taiwan University Hospital. The clinical syndromes included skin infections (n = 44), localized pulmonary infections (n = 24), and disseminated infections (n = 13). Disseminated nocardiosis included lung and brain involvement (7 patients), brain and skin involvement (2 patients), localized brain abscess (1 patient), lung involvement with bacteremia (1 patient), lymphadenitis (1 patient), and liver cirrhosis with spontaneous nocardial peritonitis (1 patient). Eleven (14%) of all patients died due to nocardiosis. In comparison with those with skin infections, patients with lung and disseminated nocardiosis tended to have chronic lung disease, malignancy, concomitant bacteremia, were often misdiagnosed as having tuberculosis, were receiving immunosuppressive treatments, and demonstrated an increased mortality. Nocardia strains isolated from patients with lung infections or disseminated infections tended to have lower in vitro antimicrobial susceptibility than those isolated from skin infections [cefotaxime: 67% (lung) vs. 86% (skin); trimethoprim/sulfamethoxazole: 75% (disseminated) vs. 97% (skin)]. These results highlight the protean disease manifestations and antimicrobial susceptibility of Nocardia and indicate the need to address the option of combined antimicrobial therapy for lung and disseminated nocardiosis.