[Clinical analysis of 26 cases of nocardiosis]

To describe the clinical characteristics of nocardiosis.

The clinical and radiological data of 26 patients with nocardiosis admitted into Peking Union Medical College Hospital from 1st January 1990 to 1st January 2010 were retrospectively analyzed. All of the patients had our microbiology laboratory identified nocardia species in one or more clinical specimens.

Nocardiosis was diagnosed in 10 men, aged from 29 to 80 years, mean (52 ± 14) years, and in 16 women, aged from 15 to 71 years, mean (42 ± 17) years. No cases were identified in children. Six patients had no significant underlying conditions, while the other patients had at least one underlying condition, including autoimmune diseases (n = 6), chronic lung disease (n = 6), neoplastic disease (n = 2), chronic renal disease (n = 3), diabetes mellitus (n = 1), chest crush injuries (n = 1) and Cushing's syndrome (n = 1). Eleven cases had been receiving corticosteroids. The most common manifestations were moderate to high fever (n = 25), cough (n = 22), expectoration (n = 19), pleuritic chest pain (n = 10), hemoptysis (n = 8) and moist rales (n = 10). Some of them had subcutaneous (n = 5) and brain abscess (n = 4). Blood tests showed elevated ESR in 14 cases and decreased albumin levels in 14 cases. Patchy infiltrates or consolidation (n = 21) and cavitations (n = 10) were the main manifestations of chest radiology. Pleural effusions (n = 13) were common complicated manifestations. Thoracic lesions were always bilateral (n = 15). Only 4 patients were diagnosed by sputum culture. The other patients were diagnosed by culture of specimens obtained invasively: 8 positive pleural effusions, 2 positive bronchioalveolar lavage culture, 1 positive bronchial washings, 4 positive abscesses, 7 positive lung tissues, and 1 positive brain abscess. Nocardia brasiliensis (n = 9) and Nocardia asteroids (n = 6) were the main species. There was one case with Nocardia otitisdiscaviarium infection and the other cases with Nocardia undifferentiated. Result of antimicrobial susceptibility was unavailable in 10 cases. Among the other 16 results, 7 strains of nocardia were resistant to trimethoprim sulfamethoxazole (TMP(CO)). Six cases were treated with a single drug, 5 cases with trimethoprim-sulfamethoxazole and 1 with minocycline. The other patients were given combination treatment, including trimethoprim-sulfamethoxazole, amikacin, cefuroxime, ceftriaxone, amoxicillin-clavulanic acid, streptomycin, evofloxacin, ciprofloxacin, minocycline and imipenem. Four patients died, 2 patients relapsed and the other 20 cases cured.

For immunosuppressed patients, nocardia infections should be considered when they had moderate to high fever and respiratory manifestations, especially accompanied with subcutaneous and/or brain abscess, and the chest radiology showed patchy infiltrates and/or consolidations. Further specific microbiological studies and sufficient therapy should be obtained as quickly as possible.