Objective  To investigate and analyze the clinical characteristics, pathogen species composition and drug sensitivity to first-line anti-tuberculosis drugs of patients with non-tuberculosis mycobacterium (NTM) pulmonary disease from Nanyang, Henan province, and provide evidence to improve the diagnosis and treatment of NTM pulmonary disease.

  Methods  A total of 276 patients with NTM pulmonary disease (all living in Nanyang) who visited the Sixth People's Hospital of Nanyang City from January 2015 to December 2019 were enrolled retrospectively. The baseline data, clinical symptoms, imaging manifestations and other information of the patients were collected, PCR reverse dot blot hybridization was used to identify NTM strains, and absolute concentration method was used for drug sensitivity test. SPSS18.0 was used for statistical analysis.

  Results  From 2015 to 2019, the identification rates of NTM patients in suspected tuberculosis (TB) patients were 1.05%, 1.11%, 1.23%, 1.54% and 1.70%, respectively. Among the 276 NTM patients, men accounted for 61.59% (170/276), and the average age of the patients at onset was（51.21 ± 8.33）years. The main clinical manifestations were cough, expectoration, chest tightness, shortness of breath or anhelation. The most common imaging manifestations were pleural thickening (53.62%, 148/276), bronchiectasis (42.39%, 117/276) and cavity (40.58%, 112/276). Eight NTM strains were identified, and the top four strains were Mycobacterium intracellular (32.61%, 90/276), Mycobacterium kansaii (23.91%, 66/276), Mycobacterium abscessus (21.38%, 59/276) and Mycobacterium avium (14.49%, 40/276). The drug resistance rates of the four major NTM to isoniazid, rifampicin, ethambutol, streptomycin, kanamycin and ofloxacin were 92.55% (236/255), 83.53% (213/255), 54.51% (139/255), 89.02% (227/255), 78.82% (201/255) and 64.31% (164/255), respectively. In NTM subspecies, M. aeruginosa was more likely to cause symptoms such as fever, chest tightness, shortness of breath or anhelation and imaging findings such as bronchiectasis and cavity compared with M. avium.

  Conclusion  The identification rate of NTM pulmonary disease in Nanyang increased year by year. The clinical characteristics were similar to those of patients with pulmonary TB. Close attention should be paid to the patients with risk factors and complications in clinical practice, and the imaging manifestations and bacteriological characteristic should be differentiated. The common NTM strains had high resistance to the first-line anti-TB drugs, so the treatment plan should be standardized.