Species distribution and spread of non-tuberculous Mycobacteria in patients of Shaanxi Provincial Tuberculosis Prevention and Control Hospital, 2019−2021

  Objective  To understand the species distribution and spread of non-tuberculous Mycobacteria ( NTM ) in Shaanxi province and provide evidence for clinical diagnosis and prevention of the infections.

  Methods  Retrospective analysis was conducted on the Mycobacterium nucleic acid positive respiratory tract samples collected in Shaanxi Provincial Tuberculosis Prevention and Control Hospital from July 2019 to December 2021. The detected NTM strains were identified by gene chip method and the composition ratio of different species was analyzed. The demographic data and clinical characteristics of the cases were analyzed by χ² test. Logistic regression analysis was used to evaluate the pathological damage degree of different NTMs in lungs based on the severity of lung lesions.

  Results  The isolation rate of NTM was 3.5% (128/3646). A total of 7 species of NTM were detected, the first 3 were M. intracellular (36.7%, 47/128), M . chelonis/abscess (26.6%, 34/128), and M. Kansas (25.0%, 32/128). The difference in distribution ratio of different NTM infected patients was significant among different age group (χ²=25.727, P<0.001) and among people with different residence (χ²=15.227, P=0.002). Multivariate logistic regression analysis showed that M. chelonis/abscess caused milder lung pathologic damage compared with the other two species (OR=0.188, P=0.039).

  Conclusion  The NTM detected in this study were mainly M. intracellular, M. chelonis/abscess and M. kansans, and different NTM caused different degrees of pathological damage in lungs.