Objective    To investigate the clinical characteristics of pulmonary nocardiosis in the immunocompetent patients so as to improve the awareness

diagnosis and treatment of this disease.     Methods    The clinical data of 3 immunocompetent patients suffering from pulmonary nocardiosis were collected and analyzed

and the related literatures were reviewed.      Results        All the 3 subjected immunocompetent patients of pulmonary nocardiosis were farmers. Their clinical manifestations were fever

cough

sputum

dyspnea

thin figure

fatigue

and so on. Abnormal laboratory findings included risen neutrophils and lactic dehydrogenase

accelerated erythrocyte sedimentation rate

and reduced albumin in the serum

but normal T lymphocyte subsets. Chest CT findings were nonspecific. Pulmonary nocardiosis was confirmed by positive nocardiosis in sputum in 2 cases and pathological examination in 1 case. All patients were treated by oral trimethoprimsulfamethoxazole (SMZco) combined with other antibiotics

and obvious efficiency was observed in all 3 patients.    Conclusion     Pulmonary nocardiosis is manifested as a chronic pulmonary infectious disease in the immunocompetent patients

with rare hematogenous and normal T lymphocyte subsets. It is usually mis-diagnosed as pulmonary tuberculosis or other bacterial infection. Pathogenic and pathological examinations are helpful for diagnosis. The treatment regimen is oral SMZco combined with other antibiotics.