Analysis on the non-tuberculosis mycobacteria isolated from the cases with tuberculosis suspicious symptoms domiciling in Yuexiu and Haizhu District of Guangzhou from 2012 to 2016

Objective To understand the prevalence of non-tuberculosis mycobacteria (NTM) in old urban areas of Guangzhou. Methods The information of NTM isolated from the cases with tuberculosis suspicious symptoms domiciling in Yuexiu and Haizhu District of Guangzhou from 2012 to 2016, based on the data of the mycobacteria cultured from laboratory of Tuberculosis Prevention and Control Institute of Yuexiu District in Guangzhou, was collected and analyzed according to year, gender, age-group (≤44, 45-65, and ≥65 years old), and seasons retrospectively. And the difference between groups was compared by χ2 test. Results (1) 1 689 strains of NTM were isolated from 40 418 samples, and the rate was 4.18%. The isolated rates from 2012 to 2016 were 4.05%, 4.58%, 3.24%, 4.67%, and 4.28% respectively, and that in 2014 was significantly lower compared with other years. There was statistically significantly difference in the isolated rate between male and female (3.64% vs.5.18%; P=0.000). The isolated rates of three age-groups were 2.85%, 5.16%, and 7.37% respectively, with statistically significantly differences between age groups (P=0.000). The isolated rates from spring to winter were 3.39%, 4.72%, 4.66%, and 4.00% respectively, with statistically significantly differences of the pairwise comparisons except for summer vs.autumn (all P<0.05). (2) In 716 identified NTM strains, the top 5 species were M.chelonae-abscessus (304 strains), M.avium complex (172 strains), M.kansasii (99 strains), M.gordonae (74 strains), and M.fortuitum (51 strains) respectively. Conclusion The prevalence of NTM in old urban districts in Guangzhou are led by M.chelonae-abscessus, M.avium complex, M.kansasii, M.gordonae, and M.fortuitum, which is mainly affected by gender, age, and season. Key words: Non-tuberculosis mycobacteria; Epidemic characteristics; Mycobacterial culture; Guangzhou