Clinical Analysis of Pulmonary Nocardiosis in a Tertiary Hospital

This study aimed to clarify the clinical characteristics of pulmonary nocardiosis in our tertiary hospital. The subjects consisted of five cases with pulmonary nocardiosis who received a definite diagnosis in our hospital from January 2006 to December 2016. The five patients with pulmonary nocardiosis included four females and one male with a mean age of 65.6 years old. All patients had underlying diseases. The detection methods were respiratory symptoms in four patients and an abnormal chest shadow in one. There were no characteristic laboratory findings. Regarding the radiological findings, an infiltration shadow was the most common finding in this study. In addition, a mass shadow that required differentiation from lung cancer was recognized in one patient. The diagnosis was reached using bronchoscopic specimens in all patients. The causative microorganisims consisted of Nocardia farcinica in three, Nocardia puris in one and Nocardia elegans in one. The drug susceptibility Totrimethoprim/Sulfamethoxazole (TMP/SMZ) was sensitive in four of five patients. Although TMP/SMZ was administered to all patients as treatment, two patients required a change of antimicrobial agents because of adverse drug events. However, the clinical effect was good for all patients because of early treatment initiation. The conclusions of this study areas follows: (1) pulmonary nocardiosis occursin immunocompetent patients with underlying respiratory diseases and patients undergoing immunosuppressive treatments; (2) there are no characteristic findings of pulmonary nocardiosis in the laboratory or radiological findings; (3) local respiratory clinical specimens using bronchoscopy were useful to obtain a definite diagnosis; (4) no patients had contracted TMP/SMZ-resistant Nocardia species and the clinical effect and prognosis were good.