title: Clinical and radiographic characteristics of pulmonary nocardiosis: clues to earlier diagnosis.
abstract: OBJECTIVE
  Pulmonary nocardiosis (PN) is a rare but life-threatening disease that is caused by Nocardia spp. The aim of this study was to characterize the common risk factors, clinical features, imaging findings, treatment and outcomes of PN, which are useful for an early diagnosis and patient management.
  
  
  METHODS
  From January 2009 to June 2013, a retrospective study was performed on all PN cases that were diagnosed at our hospital.
  
  
  RESULTS
  The study included 17 patients who were diagnosed with PN. Of these patients, 4 developed concomitant disseminated disease. A male predominance was observed among the patients with PN (76.47%). The most common risk factors were corticosteroid therapy (64.71%), diabetes mellitus (29.41) and chronic lung disease (23.53%). Cough and fever were the most common symptoms (94% and 71%, respectively). One or more nodules or masses (82.35%) and consolidations (58.82%) were the most frequent radiologic abnormalities, and cavitation mostly occurred within two weeks. The median time to diagnosis was 25 days. Overall, the mortality rate was 18.75% for PN, and death was most frequent among patients who received immunosuppressive drugs. For the patients with central nervous system involvement, the mortality rate was 50%.
  
  
  CONCLUSIONS
  PN remains a rare opportunistic infection that mainly affects immunocompromised patients. A high clinical index of suspicion is necessary for an early diagnosis and timely treatment in immunocompromised patients who present with new nodules or masses evolving into cavitation in a short amount of time.
authors.affiliation: Department of Respiratory Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.
authors.forename: Junjun
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Respiratory Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Department of Respiratory Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.
authors.forename: Panfeng
authors.initials: P
authors.lastname: Xu
authors.affiliation: Department of Respiratory Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.
authors.forename: Pei
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Department of Respiratory Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.
authors.forename: Shanni
authors.initials: S
authors.lastname: Ma
authors.affiliation: Department of Respiratory Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.
authors.forename: Jianying
authors.initials: J
authors.lastname: Zhou
mesh_terms: D000305:Adrenal Cortex Hormones / Q000009:adverse effects; D002681:China / Q000453:epidemiology; D048909:Diabetes Complications / Q000150:complications; D005260:Female; D006801:Humans; D008297:Male; D009617:Nocardia Infections / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000453:epidemiology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D061665:Time-to-Treatment; D014057:Tomography, X-Ray Computed
chemical_list: D000305:Adrenal Cortex Hormones